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+The Project Gutenberg EBook of Photographs of Nebulae and Clusters, by
+James Edward Keeler
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: Photographs of Nebulae and Clusters
+       Made with the Crossley Reflector
+
+Author: James Edward Keeler
+
+Release Date: June 19, 2011 [EBook #36470]
+
+Language: English
+
+Character set encoding: ASCII
+
+*** START OF THIS PROJECT GUTENBERG EBOOK PHOTOGRAPHS OF NEBULAE AND CLUSTERS ***
+
+
+
+
+Produced by Bryan Ness and the Online Distributed
+Proofreading Team at http://www.pgdp.net (This file was
+produced from images generously made available by The
+Internet Archive/American Libraries.)
+
+
+
+
+
+
+
+
+
+NOTE.
+
+
+In the original negatives of subjects 10 and 12, there are faint dark
+rings immediately surrounding some of the stars in the denser parts of the
+nebulosity. This effect has no doubt been accentuated in the subsequent
+photographic processes. On the plates of these two subjects in the
+completed volume, these rings are very distinct and give rise to a
+suspicion that the effect has been enhanced by the engraver. A critical
+examination of the prints seems to confirm this view. In the original
+proofs these rings were inconspicuous and were not noticed. The processes
+of steel-facing and printing appear to have increased the effect markedly,
+as it is much stronger on the sheets printed for the edition than in any
+of the early proofs.
+
+Inasmuch as these effects were not and could not be discovered until the
+sheets were assembled in Sacramento for binding, it has not been thought
+desirable to delay the issue of the volume for several weeks additional in
+order to have new plates and new prints of these subjects made by the
+distant engraver.
+
+  Lick Observatory,
+  Mount Hamilton,
+  November, 1908.
+
+
+
+
+[Illustration: _Plate 10_
+
+_THE GREAT NEBULA IN ORION_]
+
+
+
+
+  UNIVERSITY OF CALIFORNIA PUBLICATIONS
+
+  PUBLICATIONS
+  OF THE
+  LICK OBSERVATORY
+
+  PRINTED BY AUTHORITY OF THE REGENTS OF THE UNIVERSITY
+
+
+  VOLUME VIII
+
+  SACRAMENTO
+  W. W. SHANNON      SUPERINTENDENT OF STATE PRINTING
+  1908
+
+
+
+
+AS A TRIBUTE TO THE MEMORY OF
+
+JAMES EDWARD KEELER
+
+and in recognition of his great worth as a man and as an astronomer, the
+plates for this volume have been provided by
+
+  MR. WILLIAM ALVORD,            MR. F. M. SMITH,
+  MR. ROBERT BRUCE,              MISS JENNIE SMITH,
+  MR. WILLIAM H. CROCKER,        MISS MATILDA H. SMITH,
+  MRS. WILLIAM H. CROCKER,       MR. BENJAMIN THAW,
+  MR. E. J. DE SABLA,            MRS. WILLIAM THAW,
+  MR. J. A. DONOHOE,             MR. ROBERT J. TOBIN,
+  MRS. PHOEBE A. HEARST,         THE UNIVERSITY OF CALIFORNIA,
+  MR. JOHN B. JACKSON,           THE STATE OF CALIFORNIA.
+  MR. E. J. MOLERA,
+
+
+
+
+ORGANIZATION OF THE LICK OBSERVATORY.
+
+
+  HON. CHARLES W. SLACK,  HON. WARREN R. PORTER,
+
+  HON. WILLIAM H. CROCKER,  REV. PETER C. YORKE,
+
+  _Committee of the Regents for the Lick Observatory._
+
+
+  BENJAMIN IDE WHEELER,   _President of the University_.
+
+  W. W. CAMPBELL,         _Director and Astronomer_.
+
+  R. H. TUCKER,*          _Astronomer_.
+
+  C. D. PERRINE,          _Astronomer_.
+
+  H. D. CURTIS,           _Mills Acting Astronomer_.
+
+  R. G. AITKEN,           _Astronomer_.
+
+  W. H. WRIGHT,           _Astronomer_.
+
+  J. H. MOORE,            _Assistant Astronomer_.
+
+  SEBASTIAN ALBRECHT,     _Assistant Astronomer_.
+
+  MISS A. M. HOBE,        _Carnegie Assistant_.
+
+  G. F. PADDOCK,          _Mills Assistant_.
+
+  MISS L. B. ALLEN,       _Carnegie Assistant_.
+
+  E. A. FATH,             _Fellow_.
+
+  J. C. DUNCAN,           _Fellow_.
+
+  MISS A. E. GLANCY,      _Fellow_.
+
+  MISS M. E. FRENCH,*     _Secretary_.
+
+  MISS A. J. VAN COOVER,  _Secretary_.
+
+    * Absent on leave.
+
+
+
+
+  PHOTOGRAPHS OF NEBULAE AND CLUSTERS,
+  MADE WITH
+  THE CROSSLEY REFLECTOR,
+
+
+  BY JAMES EDWARD KEELER,
+  DIRECTOR OF THE LICK OBSERVATORY.
+
+
+  1898-1900.
+
+
+
+
+PREFACE.
+
+
+When Professor Keeler entered upon the duties of Director of the Lick
+Observatory, on June 1, 1898, he planned to devote his observing time for
+several years to photographing the brighter nebulae and star clusters, with
+the Crossley reflector. The story of his wonderful success with this
+difficult instrument is familiar to all readers of astronomical
+literature: this form of telescope was in effect born again; and his
+contributions to our knowledge of the nebulae were epoch-making.
+
+Professor Keeler's observing programme included one hundred and four
+subjects. At the time of his lamented death, on August 12, 1900,
+satisfactory negatives of two-thirds of the selected objects had been
+secured. The unphotographed objects were mainly those which come into
+observing position in the unfavorable winter and spring months. The
+completion of the programme was entrusted to Assistant Astronomer Perrine.
+The observers were assisted chiefly by Mr. H. K. Palmer, and in smaller
+degree by Messrs. Joel Stebbins, C. G. Dall, R. H. Curtiss and Sebastian
+Albrecht.
+
+Professor Keeler's photographs enabled him to make two discoveries of
+prime importance, not to mention several that are scarcely secondary to
+them.
+
+1st.--"Many thousands of unrecorded nebulae exist in the sky. A
+conservative estimate places the number within reach of the Crossley
+reflector at about 120,000. The number of nebulae in our catalogues is but
+a small fraction of this." [The number already discovered and catalogued
+did not exceed 13,000. Later observations with the Crossley reflector,
+with longer exposure-times and more sensitive plates, render it probable
+that the number of nebulae discoverable with this powerful instrument is of
+the order of half a million.]
+
+2d.--"Most of these nebulae have a spiral structure."
+
+The photographs of the one hundred and four subjects contain the images of
+744 nebulae not previously observed. A catalogue of these is published in
+the present volume. Their positions, which are thought to be accurate
+within 1'', were determined by Messrs. Palmer, Curtiss, and Albrecht.
+
+The main purpose of this volume is to reproduce and make available for
+study, the larger and more interesting nebulae and clusters on the
+programme, sixty-eight in number. The thirty-six subjects not reproduced
+are for the most part small or apparently not of special interest. The
+difficulties attending the reproduction of astronomical photographs by
+mechanical processes are well-known to all who have made the attempt. It
+seems necessary to recognize, at least at present, that delicate details
+of structure will be lost, and that contrasts between very bright and very
+faint regions will be changed, especially if a good sky background is
+preserved; in other words, that the best obtainable reproductions fall far
+short of doing justice to the original photographs. Technical studies
+should be based upon the original negatives or upon copies on glass.
+
+After considerable experimental work, involving several methods and
+several firms, the making of the heliogravure plates and the hand-press
+prints was entrusted to The Photogravure and Color Company of New York
+City. To this firm's continued interest and willingness to act on
+constructive criticism is due much of the excellence of the results.
+
+The expensive reproductions could hardly have been undertaken without the
+generous assistance of the donors mentioned on a preceding page.
+
+Professor Keeler's description of the Crossley reflector, of his methods
+of observing, and of the chief results obtained, was written only a short
+time before his death. It is here republished. Other results of his work
+are described in the several papers to which the footnotes refer.
+
+
+
+
+TABLE OF CONTENTS.
+
+
+  The Orion Nebula,                                         _Frontispiece_
+
+  The Crossley Reflector of the Lick Observatory,                  Page 11
+
+  List of Nebulae and Clusters Photographed,                          "  30
+
+  Catalogue of New Nebulae Discovered on the Negatives,               "  31
+
+  Positions of Known Nebulae Determined from the Crossley Negatives,  "  42
+
+  List of Illustrations,                                             "  45
+
+  Illustrations,                                          following  "  46
+
+
+
+
+THE CROSSLEY REFLECTOR OF THE LICK OBSERVATORY.[1]
+
+By JAMES E. KEELER.
+
+
+The Crossley reflector, at present the largest instrument of its class in
+America, was made in 1879 by Dr. A. A. Common, of London, in order to
+carry out, and test by practical observation, certain ideas of his
+respecting the design of large reflecting telescopes. For the construction
+of the instrument embodying these ideas, and for some fine astronomical
+photographs obtained with it, Dr. Common was awarded the gold medal of the
+Royal Astronomical Society in 1884.
+
+In 1885, Dr. Common, wishing to make a larger telescope on a somewhat
+similar plan, sold the instrument to Edward Crossley, Esq., F. R. A. S.,
+of Halifax, England. Mr. Crossley provided the telescope with a dome of
+the usual form, in place of the sliding roof used by its former owner, and
+made observations with it for some years; but the climate of Halifax not
+being suitable for the best use of such a telescope, he consented, at the
+request of Dr. Holden, then Director of the Lick Observatory, to present
+it to this institution. The funds for transporting the telescope and dome
+to California, and setting them up on Mount Hamilton, were subscribed by
+friends of the Lick Observatory, for the most part citizens of California.
+The work was completed, and the telescope housed in a suitable observatory
+building, in 1895.[2]
+
+On taking charge of the Lick Observatory in 1898, I decided to devote my
+own observing time to the Crossley reflector, although the whole of my
+previous experience had been with refracting telescopes. I was more
+particularly desirous of testing the reflector with my own hands, because
+such preliminary trials of it as had been made had given rise to somewhat
+conflicting opinions as to its merits.[3] The result of my experience is
+given in the following article, which is written chiefly with reference to
+American readers. If I have taken occasion to point out what I regard as
+defects in the design or construction of the instrument, I have done so,
+not from any desire to look a gift horse in the mouth, but in the interest
+of future improvement, and to make intelligible the circumstances under
+which the work of the reflector is now being done and will be done
+hereafter. The most important improvements which have suggested themselves
+have indeed already been made by Dr. Common himself, in constructing his
+five-foot telescope. The three-foot reflector is, in spite of numerous
+idiosyncracies which make its management very different from the
+comparatively simple manipulation of a refractor, by far the most
+effective instrument in the Observatory for certain classes of
+astronomical work. Certainly no one has more reason than I to appreciate
+the great value of Mr. Crossley's generous gift.
+
+
+[Illustration: DOME OF THE CROSSLEY REFLECTOR.]
+
+
+The Crossley dome is about 350 yards from the main Observatory, at the end
+of a long rocky spur which extends from the Observatory summit toward the
+south, and on which are two of the houses occupied by members of the
+Observatory staff. It is below the level of the lowest reservoir,
+"Huyghens," which receives the discharge from the hydraulic machinery of
+the 36-inch refractor, and therefore the water engine furnished by Mr.
+Crossley for turning the dome can not be used, unless a new water
+system--overflow reservoir, pump and windmill--is provided. In this
+respect a better site would have been a point on the south slope of
+"Kepler,"--the middle peak of Mount Hamilton--just above the Huyghens
+reservoir. No addition to the present water system would then have been
+needed. The slope of the mountain at this place might cut off the view of
+the north horizon, but since the telescope can not be turned below the
+pole, this would be a matter of no consequence. Water-power for the dome
+is not, however, really necessary.
+
+The cylindrical walls of the dome, 36-1/4 feet inside diameter, are
+double, and provided with ventilators. Opening into the dome, on the left
+of the entrance, are three small rooms, one of which has been fitted up as
+a photographic dark room, and another, containing a sidereal clock and a
+telephone, which communicates with the main Observatory, as a study, while
+the third is used for tools and storage. There is also a small room for
+the water engine, in case it should be used. The dome is at present
+supplied with water from only the middle reservoir, Kepler, which is
+reserved for domestic purposes and is not allowed to pass through the
+machinery.
+
+The dome itself, 38 feet 9 inches in diameter, is made of sheet-iron
+plates riveted to iron girders. It also carries the wooden gallery,
+ladders, and observing platform, which are suspended from it by iron rods.
+The apparatus for turning the dome consists of a cast-iron circular rack
+bolted to the lower side of the sole-plate, and a set of gears terminating
+in a sprocket-wheel, from which hangs an endless rope. As the dome does
+not turn easily, it has been necessary to multiply the gearing of the
+mechanism so that one arm's-length pull on the rope moves the dome only
+about one inch. In some positions of the telescope the dome can not be
+moved more than six or eight inches at a time without danger of striking
+the tube, and this slowness of motion is then not disadvantageous. It is
+only when the dome has to be moved through a considerable angle, as in
+turning to a fresh object, or in photographing some object which passes
+nearly through the zenith, that the need for a mechanical means of
+rotation is felt.
+
+The observing slit, 6 feet wide, extends considerably beyond the zenith.
+It is closed by a double shutter, which is operated by an endless rope.
+The upper part, within the dome, is also closed by a hood, or shield,
+which serves to protect the telescope from any water that may find its way
+through the shutter, and which is rolled back to the north when
+observations are made near the zenith. I have recently fitted the lower
+half of the slit with a wind-screen, which has proved to be a most useful
+addition. It is made of tarpaulin, attached to slats which slide between
+the two main girders, and is raised or lowered by halliards, which belay
+to cleats on the north rail of the gallery. A more detailed description of
+the dome has been given in an article by Mr. Crossley,[4] from which the
+reduced figure in Fig. 1[5] has been taken.
+
+The mounting of the three-foot reflector has been very completely
+described and illustrated by Dr. Common,[6] so that only a very general
+description need be given here. The most important feature of the
+mounting is that the telescope tube, instead of being on one side of the
+polar axis, as in the usual construction, is central, so that the axis of
+the mirror and the polar axis are in the same line when the telescope is
+directed to the pole. The declination axis is short, and is supported by a
+massive goose-neck bolted to the upper end of the polar axis. The mirror
+is placed just _above_ the declination axis. Its weight, and the weight of
+the whole tube and eye-end, are counterpoised by slabs of lead, placed in
+two iron boxes, between which the goose-neck of the polar axis passes. The
+great advantage of this arrangement, and the controlling principle of the
+design, is that the telescope is perfectly free to pass the meridian at
+all zenith distances. No reversal of the instrument is needed, or is
+indeed possible.
+
+
+[Illustration: THE CROSSLEY REFLECTOR.]
+
+
+For long-exposure photography, the advantage above referred to is obvious,
+but it is attended by certain disadvantages. One of these is that a very
+much larger dome is required than for the usual form of mounting. Another
+is the great amount of dead weight which the axes must carry; for the
+mirror, instead of helping to counterpoise the upper end of the tube, must
+itself be counterpoised. When anything is attached to the eye-end (and in
+astrophysical work one is always attaching things to the eye-end of a
+telescope), from ten to twenty times as much weight must be placed in the
+counterpoise boxes below the declination axis. Where room is to be found
+for the weights required to counterpoise the Bruce spectrograph, is a
+problem which I have not yet succeeded in solving.
+
+In his five-foot reflector, Dr. Common has caused the telescope tube to
+swing between two large ears, which project from the upper end of the
+boiler-like polar axis, the pivots constituting the declination axis being
+near, but above, the lower end of the tube. The mirror, therefore, helps
+to counterpoise the upper end of the tube. This I regard as a distinct
+improvement. The danger of large masses of metal near the mirror injuring
+the definition is, in my opinion, imaginary; at least there is no such
+danger on Mount Hamilton, where the temperature variations are unusually
+small. Experience with the Crossley reflector, as well as with the other
+instruments of the Lick Observatory, shows that the definition depends
+almost entirely on external conditions.
+
+My first trials of the reflector, as first mounted at the Lick
+Observatory, showed that the center of motion was inconveniently high.
+Among other difficulties arising from this circumstance, the spectroscope
+projected beyond the top of the dome, so that it had to be removed before
+the shutter could be closed. In July, 1898, the pier was therefore cut
+down two feet. This brought the eye-end down nearly to the level of the
+gallery rail, where it was at a convenient height for the observer when
+sitting on a camp-stool, and it made all parts of the mounting more
+accessible. Toward the north and south, the range of the telescope, being
+limited in these directions by the construction of the mounting, was not
+affected by the change, but the telescope can not now be used at such low
+altitudes as formerly, near the east and west points of the horizon. The
+only occasion likely to call for the use of the reflector in these
+positions is the appearance of a large comet near the Sun, and, after some
+consideration, I decided to sacrifice these chances for the sake of
+increasing the general usefulness of the instrument. Except in rare cases,
+all observations are made within three hours of the meridian.
+
+To adapt the mounting to the latitude of Mount Hamilton, a wedge-shaped
+casting, shown in the illustration, had been provided, but through some
+error, arising probably from the fact that the telescope had been used in
+two different latitudes in England, the angle of the casting was too
+great. When the pier was cut down its upper surface was therefore sloped
+toward the south, in order to compensate the error in the casting. Plate
+VII shows the instrument very nearly as it is at the present time.
+
+The polar axis of the Crossley reflector is a long, hollow cylinder,
+separated by a space of about one-eighth of an inch from its concentric
+casing. The idea was to fill this space with mercury, and float the
+greater part of the thrust of the axis, the function of a small steel pin
+at the lower end being merely to steady the axis. But this mercury
+flotation, as applied to the Crossley telescope, is a delusion, as I think
+Mr. Crossley had already found. The mercury, it is true, relieves the
+thrust to some extent, but it greatly increases the already enormous side
+pressure on the steel pin at the bottom, thus creating a much greater evil
+than the one it is intended to remedy. The workmen who set up the mounting
+inform me that the small bearing at the lower end of the polar axis is
+badly worn, as I should expect it to be. Instead of putting mercury into
+the space intended for it, I have therefore poured in a pint or so of oil,
+to keep the lower bearing lubricated. For the reasons indicated above, the
+force required to move the telescope in right ascension is perhaps five
+times greater than it should be. The lower end of the polar axis ought to
+be fitted with ball bearings to take the thrust, and with a pair of
+friction wheels on top; but it would be difficult to make these changes
+now. It should be observed that the disadvantages of the mercury flotation
+are considerably greater at Mount Hamilton than at the latitude for which
+the telescope was designed.
+
+
+[Illustration: THE CROSSLEY REFLECTOR.]
+
+
+As already stated above, the range of the telescope is limited on the
+south by the construction of the mounting. The greatest southern
+declination which can be observed is 25 deg.. In England this would doubtless
+mark the limit set by atmospheric conditions, but at Mount Hamilton it
+would be easy to photograph objects 15 deg. farther south, if the telescope
+could be pointed to them.
+
+The original driving-clock having proved to be inefficient, at least
+without an electric control, a new and powerful driving-clock was made by
+the Observatory instrument maker, from designs by Professor Hussey. In its
+general plan it is like that of the 36-inch refractor. The winding
+apparatus, contained in the large casting of the original mounting, has no
+maintaining power, and can not easily be fitted with one. The clock could
+in no case be wound during a photographic exposure, on account of the
+tremors attending the operation, but it would be somewhat more convenient
+to have the stars remain on the plate during the winding. With a little
+practice, however, one can wind the clock without actually stopping it,
+though the object must afterwards be brought back to its place by means of
+the slow motion in right ascension.
+
+Two finders have recently been fitted to the Crossley reflector. One has
+an object-glass of four inches aperture and eight feet six inches focal
+length, with a field of about 1 deg. 2', which is very nearly the photographic
+field of the main telescope. Its standards are bolted to one of the corner
+tubes of the reflector. The other finder has a three-inch objective and a
+large field. It had not been mounted when the photograph for the plate was
+made.
+
+When a telescope is used for photographing objects near the pole, with
+long exposures, the polar axis must be quite accurately adjusted, for
+otherwise the centers of motion of the stars and of the telescope will not
+agree, and the star images will be distorted. It is true that with a
+double-slide plate-holder, like the one used with the Crossley reflector,
+one star--namely, the guiding star--is forced to remain in a fixed
+position with respect to the plate; but the differential motion of the
+other stars causes them to describe short arcs, or trails, around this
+star as a center. A considerable part of the spring of 1899 was spent in
+efforts to perfect the adjustment of the polar axis, an operation which,
+on account of the peculiar form of the mounting, offers unusual
+difficulties.
+
+In the first plan which was tried, the reflector was used as a transit
+instrument. The inclination of the declination axis was determined with a
+hanging level which had been provided by Mr. Crossley, the hour circle and
+polar axis being very firmly clamped. The clock correction being known
+from the records kept at the Observatory, the collimation and azimuth
+constants were found by the usual formulae. This method failed to give
+satisfactory results, and it was found later that the declination and
+polar axis were not exactly at right angles.
+
+There is only one part of the sky on which the telescope can be reversed;
+namely, the pole. A method which promised well, and on which some time was
+spent, consists in photographing the pole (the declination axis being
+horizontal) by allowing the stars near it to trail for ten or fifteen
+minutes, then turning the polar axis 180 deg. and photographing the pole again
+on the same plate. Half the distance between the images gives the error of
+the polar axis, which, if the plate is properly oriented, is easily
+resolved into horizontal and vertical components; while the distance of
+each image from the center of the plate is this error increased or
+diminished by twice the deviation of the telescope axis. In this case the
+vertical component depends upon the reading of the declination circle, and
+the horizontal component gives the error of collimation. This method
+failed, however, to give consistent results, mainly on account of
+instability of the mirror, and was abandoned.
+
+The use of the large mirror for purposes of adjustment was finally given
+up, and the axis was adjusted by observations of _Polaris_ with the long
+finder, in the usual manner. In order to reach the star at lower
+culmination the finder tube had to be thrown out of parallelism with the
+main telescope.
+
+The base-plate having no definite center of rotation in azimuth, and the
+wedges and crowbars used for moving it being uncertain in their action, a
+watch telescope, provided with a micrometer eyepiece, was firmly secured
+to the mounting throughout these operations, in such manner that a mark on
+the southern horizon could be observed through one of the windows of the
+dome. The errors of the polar axis were finally reduced to within the
+limits of error of observation.
+
+The movable hour circle and driving wheel of the Crossley reflector has
+two sets of graduations. The driving screw having been thrown out of gear,
+the circle is turned until the outer vernier indicates the sidereal time,
+whereupon the driving screw is thrown into gear again. The inner vernier
+is then set to the right ascension of the object which it is desired to
+observe. As an inconsistency, of minor importance, in the design of the
+mounting, I may note that the slow motion in right ascension changes the
+reading of the outer vernier instead of that of the inner one. In
+practice, however, no inconvenience is caused by this construction.
+
+In the early experiments and photographic work with the Crossley
+telescope, irregularities in driving were a source of great annoyance. Dr.
+Roberts, in laying down the conditions which should be fulfilled by a good
+photographic telescope, says that a star should remain bisected by a
+thread in the eyepiece for two minutes at a time. The Crossley telescope
+was so far from fulfilling this condition that a star would not keep its
+place for two consecutive seconds; and the greatest alertness on the part
+of the observer did not suffice to ensure round star images on a
+photographic plate. It was obvious that the fault did not lie with the
+driving clock; in fact, many of the sudden jumps in right ascension, if
+explained in this way, would have required the clock to run backward;
+nevertheless the clock was tested by causing its revolutions to be
+recorded on a chronograph at the main Observatory, together with the beats
+of one of the standard clocks. For this purpose a break-circuit attachment
+was made by Mr. Palmer. The errors of the clock were in this way found to
+be quite small.
+
+The principal source of the irregularities was found in the concealed
+upper differential wheel of the Grubb slow motion. This wheel turned with
+uncertain friction, sometimes rotating on its axis, and sometimes
+remaining at rest. After it was checked the driving was much better, and
+was still farther improved by repairing some defective parts of the train.
+Small irregularities still remain. They seem to be partly due to
+inaccuracies in the cutting of the gears, or of the teeth of the large
+driving wheel, and partly to the springing of the various parts, due to
+the very considerable friction of the polar axis in its bearings. The
+remaining irregularities are so small, however, that they are easily
+corrected by the screws of the sliding plate-holder, and with reasonable
+attention on the part of the observer, round star images are obtained with
+exposures of four hours' duration.
+
+The large mirror, the most important part of the telescope, has an
+aperture of three feet, and a focal length of 17 feet 6.1 inches. It was
+made by Mr. Calver. Its figure is excellent. On cutting off the cone of
+rays from a star, by a knife-edge at the focus, according to the method of
+Foucault, the illumination of the mirror is very uniform, while the star
+disks as seen in an ordinary eyepiece are small and almost perfectly
+round. They are not, I think, quite so good as the images seen with a
+large refractor; still, they are very good indeed, as the following
+observations of double stars, made recently for this purpose, will show.
+
+Several close double stars were examined on the night of April 17, 1900,
+with a power of 620. The seeing was four on a scale of five. The
+magnitudes and distances of the components, as given in the table, are
+from recent observations by Professor Hussey with the 36-inch refractor.
+
+             Star.                 Mag.      _d._      Result of Obs.
+
+  [Greek: Omega Sigma] 208
+    ([Greek: phi] _Urs. Maj._)   5.0, 5.5   0''.35   Not resolved; too
+                                                      bright.
+
+  [Greek: Omega Sigma] 249, AB   7.2, 8.0   0 .54   Easily resolved.
+
+  [Greek: Omega Sigma] 250       7.7, 8.0   0 .44   Resolved.
+
+  [Greek: Omega Sigma] 267       8.0, 8.2   0 .30   Just resolved at best
+                                                      moments.
+
+Although the theoretical limit of resolution for a three-foot aperture is
+not reached in these observations, I do not think the mirror can do any
+better.
+
+The small mirror, or flat, at the upper end of the tube, is circular, the
+diameter being nine inches. Its projection on the plane of the
+photographic plate is therefore elliptical; but the projection of the
+mirror and its cell on the plane of the great mirror is very nearly
+circular.
+
+The small mirror, acting as a central stop, has the effect of diminishing
+the size of the central disk of the diffraction pattern, at the expense of
+an increase in the brightness of the system of rings. To this effect may
+be due, in part, the inferiority of the reflector for resolving bright
+doubles, as compared with a refractor of the same aperture. For
+photographic purposes, it is evident that the mirror is practically
+perfect.
+
+The upper end of the tube can be rotated, carrying with it the flat and
+the eye-end. Whenever the position is changed, the mirrors have to be
+re-collimated. In practice it is seldom necessary to touch the adjusting
+screws of the mirrors themselves. The adjustment is effected by means of
+clamping and butting screws on the eye-end, and a change of the line of
+collimation, with respect to the finders and the circles, is avoided. The
+operation is generally referred to, however, as an adjustment of the
+mirrors.
+
+For adjusting the mirrors there are two collimators. One of these is of
+the form devised by Mr. Crossley.[7] It is very convenient in use, and is
+sufficiently accurate for the adjustment of the eye-end when the telescope
+is used for photographic purposes, inasmuch as the exact place where the
+axis of the large mirror cuts the photographic plate is not then a matter
+of great importance, so long as it is near the center. Moreover, as stated
+farther below, the direction of the axis changes during a long exposure.
+The other collimator is of a form originally due, I think, to Dr.
+Johnstone Stoney. It consists of a small telescope, which fits the
+draw-tube at the eye-end. In the focus of the eyepiece are, instead of
+cross-wires, two adjustable terminals, between which an electric spark can
+be passed, generated by a small induction machine, like a replenisher,
+held in the observer's hand. The terminals are at such a distance inside
+the principal focus of the objective, that the light from the spark, after
+reflection from the flat, appears to proceed from the center of curvature
+of the large mirror. The rays are therefore reflected back normally, and
+form an image of the spark which, when the mirrors are in perfect
+adjustment, coincides with the spark itself. The precision of this method
+is very great. It is in fact out of proportion to the degree of refinement
+attained in other adjustments of the reflector, for a slight pressure of
+the hand on the draw-tube, or movement of the telescope to a different
+altitude, instantly destroys the perfection of the adjustment. I have
+provided these collimators with an adapter which fits the photographic
+apparatus, so that one can adjust the mirrors without having to remove
+this apparatus and substitute for it the ordinary eye-end carrying the
+eyepieces.
+
+For visual observation the Crossley telescope is provided with seven
+eyepieces, with powers ranging from 620 downward. The lowest power is only
+60, and consequently utilizes only 12 inches of the mirror, 9 of which are
+covered by the central flat. It is therefore of little value, except for
+finding purposes. The next lowest power utilizes 28 inches of the mirror.
+The other eyepieces call for no remark.
+
+But, while the Crossley reflector would doubtless be serviceable for
+various kinds of visual observations, its photographic applications are
+regarded as having the most importance, and have been chiefly considered
+in deciding upon the different changes and improvements which have been
+made.
+
+The interior of the dome is lighted at night by a large lamp, which is
+enclosed in a suitable box or lantern, fitted with panes of red glass, and
+mounted on a portable stand. In order to diffuse the light in the lower
+part of the dome, where most of the assistant's work is done, the walls
+are painted bright red; while to prevent reflected light from reaching the
+photographic plate, the inner surface of the dome itself, the mounting,
+and the ladders and gallery are painted dead black. The observer is
+therefore in comparative darkness, and not the slightest fogging of the
+plate, from the red light below, is produced during a four-hours'
+exposure. On the few occasions when orthochromatic plates are used the
+lamp need not be lighted.
+
+Experiments have shown that the fogging of the photographic plate, during
+a long exposure, is entirely due to diffuse light from the sky, and is
+therefore unavoidable. For this reason the cloth curtains which lace to
+the corners of the telescope tube, enclosing it and shutting out light
+from the lower part of the dome, have not been used, since their only
+effect would be to catch the wind and cause vibrations of the telescope.
+They would probably have little effect on the definition, and at any rate
+could not be expected to improve it.
+
+For photographing stars and nebulae the Crossley reflector is provided with
+a double-slide plate-holder, of the form invented by Dr. Common.[8] This
+apparatus, which had suffered considerably in transportation, and from
+general wear and tear, was thoroughly overhauled by the Observatory
+instrument-maker. The plates were straightened and the slides refitted. A
+spring was introduced to oppose the right ascension screw and take up the
+lost motion--the most annoying defect that such a piece of apparatus can
+have--and various other improvements were made, as the necessity for them
+became apparent. They are described in detail farther below.
+
+The present appearance of the eye-end is shown in the illustration. The
+plate-holder is there shown, however, on one side of the tube, and its
+longer side is parallel to the axis of the telescope. This is not a good
+position for the eye-end, except for short exposures. In practice, the
+eye-end is always placed on the north or south side of the tube, according
+as the object photographed is north or south of the zenith. The right
+ascension slide is then always at right angles to the telescope axis, and
+the eye-end can not get into an inaccessible position during a long
+exposure.
+
+As the original wooden plate-holders were warped, and could not be
+depended upon to remain in the same position for several hours at a time,
+they were replaced by new ones of metal, and clamping screws were added,
+to hold them firmly in place. The heads of these screws are shown in the
+plate, between the springs which press the plate-holder against its bed.
+
+To illuminate the cross-wires of the guiding eyepiece, a small electric
+lamp is used, the current for which is brought down from the storage
+battery at the main Observatory. The coarse wires have been replaced by
+spider's webs,[9] and reflectors have been introduced, to illuminate the
+declination thread. A collimating lens, placed at its principal focal
+distance from the incandescent filament of the lamp, makes the
+illumination of the wires nearly independent of their position on the
+slide, and a piece of red glass, close to the lens, effectually removes
+all danger of fogging the plate. The light is varied to suit the
+requirements of observation by rotating the reflector which throws the
+light in the direction of the eyepiece.
+
+
+[Illustration: DOUBLE-SLIDE PLATE-HOLDER OF THE CROSSLEY REFLECTOR.]
+
+
+In long exposures it is important for the observer to know at any moment
+the position of the plate with reference to its central or zero position.
+For this purpose scales with indexes are attached to both slides; but as
+they can not be seen in the dark, and, even if illuminated with red light,
+could not be read without removing the eye from the guiding eyepiece, I
+have added two short pins, one of which is attached to the lower side of
+the right ascension slide, and the other to its guide, so that the points
+coincide when the scale reads zero. These pins can be felt by the fingers,
+and with a little practice the observer can tell very closely how far the
+plate is from its central position. It would not be a very difficult
+matter to improve on this contrivance, say by placing an illuminated
+scale, capable of independent adjustment, in the field of the eyepiece,
+but the pins answer every purpose. The declination slide is changed so
+little that no means for indicating its position are necessary.
+
+In this apparatus, as originally constructed, the cross-wires of the
+guiding eyepiece were exactly in the plane of the photographic plate. The
+earlier observations made with the Crossley reflector on Mount Hamilton
+showed that this is not the best position of the cross-wires. The image of
+a star in the guiding eyepiece, which, when in the middle of its slide, is
+nearly three inches from the axis of the mirror, is not round, and its
+shape varies as the eyepiece is pushed in or drawn out. In the plane of
+the photographic plate (assumed to be accurately in focus), it is a
+crescent, with the convex side directed toward the center of the plate.
+This form of image is not suitable for accurate guiding. Outside this
+position the image changes to an arrow-head, the point of which is
+directed toward the axis, and this image can be very accurately bisected
+by the right ascension thread. As the construction of the apparatus did
+not allow the plane of the cross-wires to be changed, the wooden bed of
+the plate-holder was cut down, so as to bring the wires and the plate into
+the proper relative positions.
+
+After some further experience with the instrument, still another change
+was made in this adjustment. It was found that the focus often changed
+very perceptibly during a long exposure, and while the arrow-head image
+above described was suitable for guiding purposes, its form was not
+greatly affected by changes of focus. Between the crescent and the
+arrow-head images there is a transition form, in which two well-defined
+caustic curves in the aberration pattern intersect at an acute angle. The
+intersection of these caustics offers an excellent mark for the
+cross-wires, and is at the same time very sensitive to changes of focus,
+which cause it to travel up or down in the general pattern. The bed of the
+plate-holder was therefore raised, by facing it with a brass plate of the
+proper thickness.
+
+Why the focus of the telescope should change during a long exposure is not
+quite clear. The change is much too great to be accounted for by expansion
+and contraction of the rods forming the tube, following changes of
+temperature, while a simple geometrical construction shows that a drooping
+of the upper end of the tube, increasing the distance of the plate from
+the (unreflected) axis of the mirror, can not displace the focus in a
+direction normal to the plate, if it is assumed that the field is flat.
+The observed effect is probably due to the fact that the focal surface is
+not flat, but curved. During a long exposure, the observer keeps the
+guiding star, and therefore, very approximately, all other stars, in the
+same positions relatively to the plate; but he has no control over the
+position of the axis of the mirror, which, by changes of flexure, wanders
+irregularly over the field. The position of maximum curvature, therefore,
+also varies, and with it the focus of the guiding star relatively to the
+cross-wires, where the focal surface is considerably inclined to the field
+of view. It is certain that the focus does change considerably, whatever
+the cause may be, and that the best photographic star images are obtained
+by keeping the focus of the guiding star unchanged during the exposures.
+This is done by turning the focusing screw of the eye-end.
+
+In making the photographs of nebulae for which the Crossley telescope is at
+present regularly employed, it was at first our practice to adjust the
+driving-clock as accurately as possible to a sidereal rate, and then, when
+the star had drifted too far from its original position, on account of
+changes of rate or of flexure, to bring it back by the right-ascension
+slow motion, the observer either closing the slide of the plate-holder or
+following the motion of the star as best he could with the right-ascension
+screw. Lately a more satisfactory method, suggested by Mr. Palmer, has
+been employed. The slow motion in right ascension is of Grubb's form,[10]
+and the telescope has two slightly different rates, according to whether
+the loose wheel is stopped or allowed to turn freely. The driving-clock is
+adjusted so that one of these rates is too fast, the other too slow. At
+the beginning of an exposure the wheel is, say, unclamped, and the guiding
+star begins to drift very slowly toward the left, the observer following
+it with the screw of the plate-holder. When it has drifted far enough, as
+indicated by the pins mentioned farther above, the wheel is clamped. The
+star then reverses its motion and begins to drift toward the right; and so
+on throughout the exposure. The advantages of this method over the one
+previously employed are, that the star never has to be moved by the slow
+motion of the telescope, and that its general drift is in a known
+direction, so that its movements can be anticipated by the observer. In
+this way photographs are obtained, with four hours' exposure, on which the
+smallest star disks are almost perfectly round near the center of the
+plate, and from 2'' to 3'' in diameter.
+
+The star images are practically round over a field at least 1 inch or 16'
+in diameter. Farther from the center they become parabolic, but they are
+quite good over the entire plate, 3-1/4 by 4-1/4 inches.
+
+From these statements it will be seen that small irregularities in driving
+no longer present any difficulties. But certain irregular motions of the
+image still take place occasionally, and so far it has not been possible
+entirely to prevent their occurrence.
+
+It was found that the declination clamp (the long slow-motion handle
+attached to which is shown in the illustration) was not sufficiently
+powerful to hold the telescope firmly during a long exposure. A screw
+clamp was therefore added, which forces the toothed-declination sector
+strongly against an iron block just behind it, thus restoring, I think,
+the original arrangement of the declination clamp as designed by Dr.
+Common. This clamp holds the tube very firmly.
+
+The irregularities to which I have referred consist in sudden and
+unexpected jumps of the image, which always occur some time after the
+telescope has passed the meridian. These jumps are sometimes quite
+large--as much as one-sixteenth of an inch or 1. They are due to two
+causes: flexure of the tube, and sliding of the mirror on its bed. When
+the jump is due to sudden changes of flexure, the image moves very
+quickly, and vibrates before it comes to rest in its new position, and at
+the same time there is often heard a slight ringing sound from the tension
+rods of the tube. There seems to be no remedy for the sudden motions of
+this class. The tension rods are set up as tightly as possible without
+endangering the threads at their ends or buckling the large corner tubes.
+A round telescope tube, made of spirally-wound steel ribbon riveted at the
+crossings, would probably be better than the square tube now in use.
+
+Jumps due to shifting of the mirror are characterized by a gentle, gliding
+motion. They can be remedied, in part, at least, by tightening the copper
+bands which pass around the circumference of the mirror within its cell.
+This will be done the next time the mirror is resilvered.
+
+All that the observer can do when a jump occurs is to bring back the image
+as quickly as possible to the intersection of the cross-wires. If all the
+stars on the plate are faint, no effect will be produced on the
+photograph; but stars of the eighth magnitude or brighter will leave short
+trails. The nebula, if there is one on the plate, will, of course, be
+unaffected.
+
+Before beginning an exposure the focus is adjusted by means of a
+high-power positive eyepiece. An old negative, from which the film has
+been partially scraped, is placed in one of the plate-holders, and the
+film is brought into the common focus of the eyepiece and the great
+mirror. The appearance of the guiding star, which varies somewhat with the
+position of the guiding eyepiece on its slide, is then carefully noted,
+and is kept constant during the exposure by turning, when necessary, the
+focusing screw of the eye-end. For preliminary adjustments a ground-glass
+screen is often convenient. On it all the _DM._ stars, and even
+considerably fainter ones, as well as the nebulae of Herschel's Class I,
+are easily visible without a lens.
+
+Plates are backed, not more than a day or two before use, with Carbutt's
+"Columbian backing," which is an excellent preparation for this purpose.
+During the exposure the observer and assistant exchange places every half
+hour, thereby greatly relieving the tediousness of the work, though two
+exposures of four hours each, in one night, have proved to be too
+fatiguing for general practice. At the end of the first two hours it is
+necessary to close the slide and wind the clock.
+
+The brightness of the guiding star is a matter of some importance. If the
+star is too bright, its glare is annoying; if it is too faint, the effort
+to see it strains the eye, and changes of focus are not easily recognized.
+A star of the ninth magnitude is about right. In most cases a suitable
+star can be found without difficulty.
+
+In such an apparatus as that described above, the amount by which the
+plate may be allowed to depart from its zero position is subject to a
+limitation which has not, I think, been pointed out, although it is
+sufficiently obvious when one's attention has been called to it. It
+depends upon the fact that the plate necessarily moves as a whole, in a
+straight line which is tangent to a great circle of the sphere, while the
+stars move on small circles around the pole. The compensation for drift,
+when the plate is moved, is therefore exact at the equator only.
+
+Let the guiding star have the declination [Greek: delta]_{1}, and let a
+star on the upper edge of the plate (which, when the telescope is north of
+the zenith, and the eye-end is on the north side of the telescope, will be
+the southern edge) have the declination [Greek: delta]_{2}. Then if the
+guiding star is allowed to drift from its zero position through the
+distance _d_, the other star will drift through the distance _d_ (cos
+[Greek: delta]_{2} / cos [Greek: delta]_{1}). If the guiding star is
+followed by turning the right-ascension screw, the upper edge of the
+plate, as well as the guiding eyepiece, will be moved through the distance
+_d_. Hence there will be produced an elongation of the upper star,
+represented by
+
+  _e_ = _d_ ((cos [Greek: delta]_{2} / cos [Greek: delta]_{1}) - 1)
+
+  from which _d_ = (_e_ cos [Greek: delta]_{1}) /
+                    (cos [Greek: delta]_{2} - cos [Greek: delta_{1}]).
+
+Now, in the Crossley reflector, the upper edge of the plate and the
+guiding eyepiece are just about 3-2/3 inches, or 1 deg., apart. If _e_ is
+given, the above formula serves to determine the maximum range of the
+slide for different positions of the telescope.
+
+It has been stated farther above that the smallest star disks, on a good
+photograph, are sometimes not more than 2'' in diameter, or in a linear
+measure, about 1/20 mm. An elongation of this amount is therefore
+perceptible. There are many nebulae in high northern declinations, and
+there are several particularly fine ones in about +70 deg.. If, therefore, we
+take [Greek: delta]_{2} = 70 deg., [Greek: delta]_{1}, = 71 deg., _e_ = 0.05, and
+substitute these values, we find _d_ = 1.0 mm, which is the greatest
+permissible range of the plate in photographing these nebulae. Before I
+realized the stringency of this requirement, by making the above simple
+computation, I spoiled several otherwise fine negatives by allowing the
+plate to get too far from the center, thus producing elongated star
+images.
+
+There is a corresponding elongation in declination, the amount of which
+can be determined by an adaptation of the formula for reduction to the
+meridian, but it is practically insensible.
+
+On account of the short focal length of the three-foot mirror, the
+photographic resolving power of the telescope is much below its optical
+resolving power. For this reason the photographic images are less
+sensitive to conditions affecting the seeing than the visual images. On
+the finest nights the delicate tracery of bright lines or caustic curves
+in the guiding star is as clear and distinct as in a printed pattern. When
+the seeing is only fair these delicate details are lost, and only the
+general form of the image, with its two principal caustics, is seen. A
+photograph taken on such a night is not, however, perceptibly inferior to
+one taken when the seeing is perfect. When, however, the image is so
+blurred that its general form is barely distinguishable, the photographic
+star disks are likewise blurred and enlarged, and on such nights
+photographic work is not attempted.
+
+The foregoing account of the small changes which have been made in the
+Crossley telescope and its accessories may appear to be unnecessarily
+detailed, yet these small changes have greatly increased the practical
+efficiency of the instrument, and, therefore, small as they are, they are
+important. Particularly with an instrument of this character, the
+difference between poor and good results lies in the observance of just
+such small details as I have described.
+
+At present the Crossley reflector is being used for photographing nebulae,
+for which purpose it is very effective. Some nebulae and clusters, like the
+great nebula in _Andromeda_ and the _Pleiades_, are too large for its
+plate (3-1/4 x 4-1/4 in.), but the great majority of nebulae are very much
+smaller, having a length of only a few minutes of arc, and a large-scale
+photograph is required to show them satisfactorily. It is particularly
+important to have the images of the involved stars as small as they can be
+made.
+
+Many nebulae of Herschel's I and II classes are so bright that fairly good
+photographs can be obtained with exposures of from one to two hours; but
+the results obtained with full-light action are so superior to these, that
+longer exposures of three and one half or four hours are always preferred.
+In some exceptional cases, exposures of only a few minutes are sufficient.
+The amount of detail shown, even in the case of very small nebulae, is
+surprising. It is an interesting fact that these photographs confirm (in
+some cases for the first time) many of the visual observations made with
+the six-foot reflector of the Earl of Rosse.
+
+Incidentally, in making these photographs, great numbers of new nebulae
+have been discovered. The largest number that I have found on any one
+plate is thirty-one. Eight or ten is not an uncommon number, and few
+photographs have been obtained which do not reveal the existence of three
+or four. A catalogue of these new objects will be published in due time.
+
+Some of the results obtained with the Crossley reflector, relating chiefly
+to particular objects of some special interest, have already been
+published.[11] The photographs have also permitted some wider conclusions
+to be drawn, which are constantly receiving further confirmation as the
+work progresses. They may be briefly summarized as follows:
+
+1. Many thousands of unrecorded nebulae exist in the sky. A conservative
+estimate places the number within reach of the Crossley reflector at about
+120,000. The number of nebulae in our catalogues is but a small fraction of
+this.
+
+2. These nebulae exhibit all gradations of apparent size, from the great
+nebula in _Andromeda_ down to an object which is hardly distinguishable
+from a faint star disk.
+
+3. Most of these nebulae have a spiral structure.
+
+To these conclusions I may add another, of more restricted significance,
+though the evidence in favor of it is not yet complete. Among the objects
+which have been photographed with the Crossley telescope are most of the
+"double" nebulae figured in Sir John Herschel's catalogue (_Phil. Trans._,
+1833, Plate XV). The actual nebulae, as photographed, have almost no
+resemblance to the figures. They are, in fact, spirals, sometimes of very
+beautiful and complex structure; and, in any one of the nebulae, the
+secondary nucleus of Herschel's figure is either a part of the spiral
+approaching the main nucleus in brightness, or it can not be identified
+with any real part of the object. The significance of this somewhat
+destructive conclusion lies in the fact that these figures of Herschel
+have sometimes been regarded as furnishing analogies for the figures which
+Poincare had deduced, from theoretical considerations, as being among the
+possible forms assumed by a rotating fluid mass; in other words, they have
+been regarded as illustrating an early stage in the development of double
+star systems. The actual conditions of motion in these particular nebulae,
+as indicated by the photographs, are obviously very much more complicated
+than those considered in the theoretical discussion.
+
+While I must leave to others an estimate of the importance of these
+conclusions, it seems to me that they have a very direct bearing on many,
+if not all, questions concerning the cosmogony. If, for example, the
+spiral is the form normally assumed by a contracting nebulous mass, the
+idea at once suggests itself that the solar system has been evolved from a
+spiral nebula, while the photographs show that the spiral nebula is not,
+as a rule, characterized by the simplicity attributed to the contracting
+mass in the nebular hypothesis. This is a question which has already been
+taken up by Professor Chamberlin and Mr. Moulton of the University of
+Chicago.
+
+The Crossley reflector promises to be useful in a number of fields which
+are fairly well defined. It is clearly unsuitable for photographing the
+Moon and planets, and for star charting. On the other hand, it has proved
+to be of value for finding and photographically observing asteroids whose
+positions are already approximately known.
+
+One of the most fruitful fields for this instrument is undoubtedly stellar
+spectroscopy. Little has been done in this field, as yet, with the
+Crossley reflector, but two spectrographs, with which systematic
+investigations will be made, have nearly been completed by the Observatory
+instrument-maker. One of these, constructed with the aid of a fund given
+by the late Miss C. W. Bruce, has a train of three 60 deg. prisms and one 30 deg.
+prism, and an aperture of two inches; the other, which has a single quartz
+prism, will, I have reason to expect, give measurable, though small,
+spectra of stars nearly at the limit of vision of the telescope.
+
+The photogravure[12] of the Trifid nebula, which accompanies this article,
+was made from a photograph taken with the Crossley reflector on July 6,
+1899, with an exposure of three hours. It was not selected as a specimen
+of the work of the instrument, for the negative was made in the early
+stages of the experiments that I have described, and the star images are
+not good, but rather on account of the interest of the subject. At the
+time the photogravures were ordered no large scale photograph of the
+Trifid nebula had, so far as I am aware, ever been published.[13] The
+remarkable branching structure of the nebula is fairly well shown in the
+photogravure, though less distinctly than in the transparency from which
+it was made. The enlargement, as compared with the original negative, is
+2.9 diameters (1 mm = 13''). The fainter parts of the nebula would be
+shown more satisfactorily by a longer exposure.
+
+LIST OF NEBULAE AND CLUSTERS PHOTOGRAPHED.
+
+  +----------------------------------------------------------------------+
+  |N.G.C.| [Greek: a]|[Greek: d]|            Remarks.                    |
+  |  No. |  1900.0   |  1900.0  |                                        |
+  |----------------------------------------------------------------------|
+  |      |  h  m  s  |   deg.   '   |                                        |
+  | 185  |  0 33 25  | +47 47.3 |H II, 707                               |
+  | 205  |  0 34 56  | +41  8.2 |H V, 18                                 |
+  | 221  |  0 37 15  | +40 19.0 |M 32                                    |
+  | 224  |  0 37 17  | +40 43.4 |Great nebula in _Andromeda_             |
+  | 247  |  0 42 3   | -21 17.9 |H V, 20                                 |
+  | 253  |  0 42 36  | -25 50.6 |H V, I                                  |
+  | 524  |  1 19 33  | + 9  1.0 |H I, 151                                |
+  | 598  |  1 28 12  | +30  8.6 |M 33                                    |
+  | 628  |  1 31 19  | +15 16   |M 74                                    |
+  | 650  |  1 36 0   | +51  4.0 |M 76                                    |
+  | 891  |  2 16 15  | +41 53.6 |H V, 19                                 |
+  |1023  |  2 34 8   | +38 38.0 |H I, 156                                |
+  |1068  |  2 37 34  | - 0 26.3 |M 77                                    |
+  |1084  |  2 41 5   | - 8  0.0 |H I, 64                                 |
+  | ...  |  3 41     | +24      |_Pleiades_ in _Taurus_                  |
+  |1555  |  4 16 8   | +19 17   |T _Tauri_ and Hind's variable nebula    |
+  |1931  |  5 24 48  | +34 10.1 |H I, 261                                |
+  |1952  |  5 28 30  | +21 57   |Crab nebula in _Taurus_                 |
+  | ...  |  5 30     | - 5      |Great nebula in _Orion_                 |
+  |1977  |  5 30 27  | - 4 54.2 |H V, 30                                 |
+  |2024  |  5 36 48  | - 1 54.3 |H V, 28                                 |
+  |2068  |  5 41 37  | + 0  0.8 |M 78                                    |
+  |2239  |  6 25 37  | + 5  1.1 |Cluster and nebula in _Monoceros_       |
+  |2264  |  6 35     | +10  0   |Nebula near 15 _Monocerotis_            |
+  |2287  |  6 42 43  | -20 38.4 |M 14                                    |
+  | ...  |  6 59 40  | -10 18.2 |New nebula in _Monoceros_               |
+  |2359  |  7 12 54  | -13  2.0 |H V, 21                                 |
+  |2366  |  7 18 18  | +69 13.4 |H III, 748                              |
+  |2371-2|  7 19  6  | +29 41.0 | H II, 316-7                            |
+  |2403  |  7 27  9  | +65 48.9 |H V, 44                                 |
+  |2437  |  7 35 24  | -14 35.3 |Cluster and nebula M 46                 |
+  |2632  |  8 34     | +20      |_Praesepe_ cluster                       |
+  |2683  |  8 46 29  | +33 47.8 |H I, 200                                |
+  |2841  |  9 15  6  | +51 24   |H I, 205                                |
+  |2903-0|  9 26 31  | +21 57   |H I, 56-57                              |
+  |3003  |  9 42 38  | +33 52.8 |H V, 26                                 |
+  |3031  |  9 47 18  | +69 32   |M 81                                    |
+  |3079  |  9 55  9  | +56 10.1 |H V, 47                                 |
+  |3115  | 10  0 16  | - 7 14.0 |H I, 163                                |
+  |3169  | 10  9  4  | + 3 57.7 |H I, 4                                  |
+  |3184  | 10 12 15  | +41 55.1 |H I, 168                                |
+  |3198  | 10 13 42  | +46  3.7 |H I, 199                                |
+  |3226-7| 10 17 59  | +20 24.1 |H II, 28-29                             |
+  |3242  | 10 19 29  | -18  5   |H IV, 27                                |
+  | ...  | 10 21  7  | +68 58   |New nebula in _Ursa Major_ (Coddington).|
+  |3556  | 11  5 40  | +56 13.0 |H V, 46                                 |
+  |3587  | 11  9  0  | +55 33.7 |Owl nebula, M 97                        |
+  |3623  | 11 13 43  | +13 38.4 |M 65                                    |
+  |3627  | 11 15  1  | +13 32   |M 66                                    |
+  |3726  | 11 27 56  | +47 35.8 |H II, 730                               |
+  |4244  | 12 12 29  | +38 22.0 |H V, 41                                 |
+  |4254  | 12 13 45  | +14 59   |M 99                                    |
+  |4258  | 12 14  2  | +47 51.6 |H V, 43                                 |
+  |4303  | 12 16 18  | + 5  1.7 |M 61                                    |
+  |4321  | 12 17 52  | +16 22.7 |M 100                                   |
+  |4382  | 12 20 21  | +18 44.7 |M 85                                    |
+  |4485-9| 12 25 40  | +42 15.3 |H I, 197-198                            |
+  |4501  | 12 26 56  | +14 58.5 |M 88                                    |
+  |4536  | 12 29 20  | + 2 44.2 |H V, 2                                  |
+  |4559  | 12 30 59  | +28 30.6 |H I, 92                                 |
+  |4565  | 12 31 24  | +26 32.2 |H V, 24                                 |
+  |4631  | 12 37 19  | +33  5.9 |H V, 42                                 |
+  |4656-5| 12 39  6  | +32 42.8 |H I, 176-7                              |
+  |4725  | 12 45 33  | +26  3   |H I, 84                                 |
+  |4736  | 12 46 13  | +41 39.5 |M 94                                    |
+  |4826  | 12 51 49  | +22 13.9 |M 64                                    |
+  |5055  | 13 11 20  | +42 33.6 |M 63                                    |
+  |5194-5| 13 25 39  | +47 42.6 |M 51                                    |
+  |5247  | 13 32 39  | -17 22.4 |H II, 297                               |
+  |5272  | 13 37 35  | +28 53   |M 3                                     |
+  |5457-8| 13 59 39  | +54 50   |M 101                                   |
+  |5857-9| 15  2 55  | +19 58.9 |H II, 751-2                             |
+  |5866  | 15  3 45  | +56  9.0 |H I, 215                                |
+  |5904  | 15 13 29  | + 2 27   |M 5                                     |
+  |6205  | 16 38  6  | +36 39.0 |M 13                                    |
+  |6218  | 16 42  2  | - 1 46.2 |M 12                                    |
+  |6412  | 17 32 41  | +75 47.3 |H VI, 41                                |
+  |6514  | 17 55 43  | -23  2   |Trifid nebula in _Sagittarius_          |
+  |6523  | 17 57 43  | -24 23   |M 8                                     |
+  |6543  | 17 58 35  | +66 38   |H IV, 37                                |
+  |6618  | 18 15  0  | -16 13   |M 17 Omega nebula                       |
+  |6656  | 18 30 17  | -23 59.3 |M 22                                    |
+  |6705  | 18 45 42  | - 6 23.3 |M 11                                    |
+  |6720  | 18 49 53  | +32 54.0 |M 57                                    |
+  |6853  | 19 55 17  | +22 27   |Dumb-Bell nebula                        |
+  |6894  | 20 12 22  | +30 15.5 |H IV, 13                                |
+  |6946  | 20 32 48  | +59 48.0 |H IV, 76                                |
+  |6951  | 20 35 47  | +65 45.4 |                                        |
+  |6995  | 20 53  0  | +30 49.8 |                                        |
+  |7008  | 20 57 38  | +54 9.5  |H I, 192                                |
+  |7009  | 20 58 11  | -11 48   |H IV, 1                                 |
+  |7023  | 21  0 30  | +67 46.2 |H IV, 74                                |
+  |7078  | 21 25  9  | +11 43.7 |M 15                                    |
+  |7089  | 21 28 19  | - 1 16.0 |M 2                                     |
+  |7099  | 21 34 42  | -23 38.0 |M 30                                    |
+  |7217  | 22  3 24  | +30 52.3 |H II, 207                               |
+  |7331  | 22 32 30  | +33 53.9 |H I, 53                                 |
+  |7448  | 22 55  7  | +15 26.6 |H II, 251                               |
+  |7479  | 22 59 56  | +11 47.0 |H I, 55                                 |
+  |7537-4| 23  9 38  | + 3 59.4 |H II, 429-30                            |
+  |7662  | 23 21  5  | +41 59.2 |H IV, 18                                |
+  |7782  | 23 48 47  | + 7 24.8 |H III, 233                              |
+  |7814  | 23 58  8  | +15 34.5 |H II, 240                               |
+  |7817  | 23 58 52  | +20 11.6 |H II, 227                               |
+  +----------------------------------------------------------------------+
+
+
+CATALOGUE OF NEW NEBULAE DISCOVERED ON THE NEGATIVES.
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |  1| 0  0 27.4| +3.0732  |+20 34 57 | +20.048  |vS eeF                |
+  |  2| 0 32  7.7|  3.2795  |+47 55 29 |  19.855  |eF N                  |
+  |  3| 0 32  8.1|  3.2801  |+48  1 22 |  19.855  |F vbM E140 deg.           |
+  |  4| 0 32  9.3|  3.2776  |+47 37 24 |  19.855  |eF bM                 |
+  |  5| 0 32 28.8|  3.2799  |+47 39  5 |  19.851  |B vE70 deg.               |
+  |  6| 0 33 23.9|  3.2674  |+47 55  5 |  19.841  |eF vS                 |
+  |  7| 0 35 43.1|  3.3009  |+47 46 18 |  19.810  |eF vS                 |
+  |  8| 0 40 51.1|  2.9793  |-21 25 48 |  19.730  |18 vS R               |
+  |  9| 0 47  0.1|  2.9804  |-21  9 17 |  19.727  |16 vS bM 3 sep. parts |
+  | 10| 0 41 16.2|  2.9781  |-21 29 43 |  19.723  |18 vS R bM            |
+  | 11| 0 41 16.7|  2.9792  |-21 15  2 |  19.723  |18 vS R               |
+  | 12| 0 41 29.7|  2.9798  |-21  3  8 |  19.719  |18 vS bM E50 deg.         |
+  | 13| 0 42  4.4|  2.9633  |-26  0  7 |  19.711  |17 vS R bsw           |
+  | 14| 0 42 30.7|  2.9780  |-20 56 38 |  19.703  |18 vS bM E115 deg.        |
+  | 15| 0 42 34.2|  2.9620  |-25 59 10 |  19.702  |17 vS N E160 deg.         |
+  | 16| 0 42 37.6|  2.9776  |-20 58 28 |  19.701  |14 S E stell N        |
+  | 17| 0 42 39.7|  2.9772  |-21  1 54 |  19.701  |17 vS Spiral bM       |
+  | 18| 0 42 39.9|  2.9774  |-21  0  3 |  19.700  |18 vS Ring?           |
+  | 19| 0 42 40.5|  2.9770  |-21  3 55 |  19.700  |15 S Spiral N bM      |
+  | 20| 0 42 40.6|  2.9762  |-21 13 54 |  19.700  |18 vS R               |
+  | 21| 0 43 10.4|  2.9603  |-25 59 36 |  19.692  |18 vS R bM            |
+  | 22| 0 43 16.2|  2.9730  |-21 37 17 |  19.691  |18 vS dif             |
+  | 23| 0 43 27.1|  2.9613  |-25 40 21 |  19.688  |17 vS R N             |
+  | 24| 0 43 29.0|  2.9593  |-26  0 57 |  19.687  |18 vS R gbM           |
+  | 25| 0 44 10.8|  2.9714  |-21 30 29 |  19.676  |18 vS R               |
+  | 26| 0 44 26.6|  2.9735  |-20 58 35 |  19.672  |17 vS R bM            |
+  | 27| 1 18 30.9|  3.1475  |+ 9 27 25 |  18.887  |F S N                 |
+  | 28| 1 18 53.5|  3.1475  |+ 9 24 28 |  18.875  |F vbM Spiral?         |
+  | 29| 1 19 11.3|  3.1474  |+ 9 21 53 |  18.867  |F vbM Spiral?         |
+  | 30| 1 19 30.7|  3.1467  |+ 9 14 18 |  18.857  |F bM E                |
+  | 31| 1 29 50.7|  3.2101  |+15  6 37 |  18.526  |pF E45 deg. bp            |
+  | 32| 1 29 54.4|  3.2161  |+15 43 25 |  18.524  |F R                   |
+  | 33| 1 30 20.9|  3.2127  |+15 17 38 |  18.509  |vF L R                |
+  | 34| 1 30 24.7|  3.2132  |+15 20 28 |  18.507  |pF S vF extension 135 deg.|
+  | 35| 1 30 35.9|  3.2153  |+15 32  2 |  18.501  |S pB pmb M            |
+  | 36| 1 30 54.7|  3.2176  |+15 43  1 |  18.491  |vvF vS                |
+  | 37| 1 31  5.0|  3.2179  |+15 43 38 |  18.485  |F S E95 deg.              |
+  | 38| 1 31 15.9|  3.2159  |+15 30 44 |  18.478  |pF S R                |
+  | 39| 1 31 25.7|  3.2187  |+15 44 34 |  18.473  |vF S R                |
+  | 40| 1 31 44.8|  3.2194  |+15 46 49 |  18.462  |F L R gbM             |
+  | 41| 1 31 44.8|  3.2126  |+15  4 18 |  18.462  |F L gbM R             |
+  | 42| 1 32  5.9|  3.2158  |+15 20 54 |  18.450  |S pB E135 deg.            |
+  | 43| 1 32 41.3|  3.2171  |+15 23 22 |  18.430  |vF S E45 deg.             |
+  | 44| 1 32 48.8|  3.2156  |+15 12 27 |  18.424  |vF pL                 |
+  | 45| 1 33 10.4|  3.2168  |+15 16 49 |  18.413  |vF pL gbM             |
+  | 46| 1 33 13.2|  3.2166  |+15 15 14 |  18.412  |p B R gbM             |
+  | 47| 2 14 10.2|  3.7341  |+41 50  8 |  16.715  |pF E135 deg.              |
+  | 48| 2 14 26.6|  3.7349  |+41 49  1 |  16.701  |pB N R                |
+  | 49| 2 14 33.9|  3.7307  |+41 37 31 |  16.696  |B N                   |
+  | 50| 2 14 36.7|  3.7313  |+41 38 24 |  16.694  |F                     |
+  | 51| 2 14 55.0|  3.7506  |+42 24 20 |  16.677  |eF vS bM E135 deg.        |
+  | 52| 2 15  6.2|  3.7517  |+42 25  6 |  16.668  |F gbM E130 deg. Spiral?   |
+  | 53| 2 15 14.9|  3.7493  |+42 16 44 |  16.661  |F pmbM                |
+  | 54| 2 15 16.1|  3.7484  |+42 14  4 |  16.659  |F B_{*}f              |
+  | 55| 2 15 38.4|  3.7666  |+42 55  0 |  16.641  |eF vS R               |
+  | 56| 2 15 43.8|  3.7503  |+42 13 58 |  16.637  |S F R                 |
+  | 57| 2 15 56.5|  3.7724  |+43  5 24 |  16.626  |F E170 deg. bsf           |
+  | 58| 2 16  1.0|  3.7539  |+42 20 55 |  16.623  |B S vbM E150 deg. bnp     |
+  | 59| 2 16  6.4|  3.7403  |+41 44 51 |  16.619  |S F R                 |
+  | 60| 2 16  9.7|  3.7408  |+41 45 26 |  16.616  |F S pmbM              |
+  | 61| 2 16 13.0|  3.7613  |+42 36 32 |  16.613  |pB vbM E150 deg. Spiral?  |
+  | 62| 2 16 31.1|  3.7640  |+42 39 27 |  16.598  |eeF E50 deg.              |
+  | 63| 2 16 34.5|  3.7412  |+41 42  6 |  16.595  |pB pmbM               |
+  | 64| 2 16 40.3|  3.7620  |+42 33 22 |  16.591  |B S pbM               |
+  | 65| 2 16 43.3|  3.7403  |+41 38 14 |  16.588  |pB E0 deg. pmbM           |
+  | 66| 2 16 53.2|  3.7625  |+42 32 12 |  16.580  |vB S mbM              |
+  | 67| 2 16 57.8|  3.7567  |+42 16 48 |  16.576  |F triN npN            |
+  | 68| 2 17 13.8| +3.7403  |+42 22 37 | +16.563  |pB bs B_{*}p          |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  +----------------------------------------------------------------------+
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  | 69| 2 17 18.9| +3.7661  |+42 36 12 | +16.559  |pS pB gbM E40 deg.        |
+  | 70| 2 17 28.5|  3.7415  |+41 33  3 |  16.551  |pF S R                |
+  | 71| 2 17 28.8|  3.7560  |+42  9 35 |  16.551  |vF                    |
+  | 72| 2 17 33.2|  3.7606  |+42 20 17 |  16.547  |F vS bnp              |
+  | 73| 2 17 36.2|  3.7789  |+43  3 25 |  16.545  |eeF S                 |
+  | 74| 2 17 37.2|  3.7469  |+41 45  2 |  16.544  |F vL vmbM             |
+  | 75| 2 17 41.8|  3.7592  |+42 15  8 |  16.540  |S pB bs               |
+  | 76| 2 17 43.3|  3.7554  |+42  5 21 |  16.539  |F bsp                 |
+  | 77| 2 17 44.6|  3.7441  |+42 18 28 |  16.538  |B S E90 deg. bM           |
+  | 78| 2 17 45.5|  3.7425  |+42 22 45 |  16.537  |F L bM N B_{*}np      |
+  | 79| 2 17 50.8|  3.7743  |+42 50 20 |  16.533  |pB gbM E135 deg.          |
+  | 80| 2 17 51.1|  3.7484  |+41 46 22 |  16.532  |pB E135 deg. gbM          |
+  | 81| 2 18  0.2|  3.7743  |+42 48 30 |  16.525  |vF pL gbM E50 deg.        |
+  | 82| 2 18  0.8|  3.7502  |+41 48 55 |  16.525  |pF L                  |
+  | 83| 2 18  4.2|  3.7603  |+42 14  0 |  16.522  |S B vbM               |
+  | 84| 2 18 14.8|  3.7579  |+42  7 27 |  16.513  |pB E150 deg. Spiral       |
+  | 85| 2 18 23.6|  3.7792  |+42 56 10 |  16.507  |eeF pL E120 deg.          |
+  | 86| 2 18 26.7|  3.7604  |+42 10  8 |  16.503  |vB E45 deg.               |
+  | 87| 2 18 30.7|  3.7465  |+41 34 13 |  16.499  |F E150 deg. bnf           |
+  | 88| 2 18 33.5|  3.7784  |+42 52 19 |  16.498  |B S gbM               |
+  | 89| 2 18 34.0|  3.7628  |+42 14 44 |  16.497  |vS vF bsp             |
+  | 90| 2 18 37.4|  3.7837  |+43  4 26 |  16.495  |S F bs                |
+  | 91| 2 31 51.3|  3.7209  |+38 16 30 |  15.806  |vF vS                 |
+  | 92| 2 33 53.9|  3.7295  |+38 19 27 |  15.694  |F vS N                |
+  | 93| 2 33 56.7|  3.7461  |+38 49 15 |  15.691  |F S bn E0 deg. long N     |
+  | 94| 2 34  7.5|  3.7405  |+38 43  4 |  15.681  |pF S i triN           |
+  | 95| 2 34  9.2|  3.7399  |+38 43 10 |  15.680  |pF vS                 |
+  | 96| 2 34 11.8|  3.7259  |+38  7 39 |  15.678  |F L E40 deg. Spiral on    |
+  |   |          |          |          |          |  edge                |
+  | 97| 2 34 44.2|  3.7402  |+38 38 27 |  15.648  |eeeF doubtful         |
+  | 98| 2 34 44.4|  3.7488  |+38 16 16 |  15.648  |pB N E50 deg. S pmbM      |
+  | 99| 2 35  1.0|  3.7469  |+38 18 45 |  15.632  |L F pmbM              |
+  |100| 2 36 32.9|  3.7436  |+38 30 26 |  15.548  |S F E100 deg.             |
+  |101| 2 36 53.3|  3.0662  |- 0 24 48 |  15.525  |vS vF gbM             |
+  |102| 2 37  6.0|  3.0728  |- 0  2 43 |  15.518  |vS F m E30 deg.           |
+  |103| 2 38 44.2|  3.0688  |- 0 16 20 |  15.427  |F S m E80 deg.            |
+  |104| 2 41 11.6|  2.9503  |- 8  3 17 |  15.294  |pB vS E135 deg.           |
+  |105| 2 41 53.7|  2.9564  |- 7 38  9 |  15.254  |vF vS mbM             |
+  |106| 2 42 18.9|  2.9499  |- 8  2 27 |  15.230  |eeF S                 |
+  |107| 4 35 22.9|  3.0244  |- 2 12 20 |   7.235  |16 S E165 deg. Dif bM     |
+  |108| 4 36  0.6|  3.0307  |- 1 54 37 |   7.183  |18 vS R               |
+  |109| 4 36  3.6|  3.0300  |- 1 56 42 |   7.179  |17 vS R stell         |
+  |110| 4 36 12.7|  3.0337  |- 1 46 19 |   7.167  |16 vS nearly R bM     |
+  |111| 4 36 15.2|  3.0238  |- 2 13 38 |   7.164  |18 vS R (Spiral?)     |
+  |112| 4 36 40.5|  3.0251  |- 2  9 53 |   7.129  |18 vS R N             |
+  |113| 4 36 41.2|  3.0293  |- 1 58 23 |   7.128  |18 vS E30 deg. bn         |
+  |114| 4 37  2.4|  3.0268  |- 2  5 10 |   7.099  |18 vS dif             |
+  |115| 4 37 26.8|  3.0298  |- 1 56 51 |   7.066  |15 vS Spiral B N      |
+  |   |          |          |          |          |  (stell)             |
+  |116| 5 24 48.1|  3.9674  |+34  6 28 | + 3.075  |bright stell N on     |
+  |   |          |          |          |          |  north side          |
+  |117| 7 14  0.7|  6.4903  |+69 39 20 | - 6.362  |17 vS bM              |
+  |118| 7 14 24.5|  6.4656  |+69 31 49 |   6.395  |17 vS N Ring          |
+  |119| 7 14 37.5|  6.4241  |+69 18 15 |   6.413  |17 R bM               |
+  |120| 7 15 45.6|  6.4282  |+69 21 35 |   6.507  |17 vS                 |
+  |121| 7 15 50.7|  6.4875  |+69 41 26 |   6.514  |16 vS R               |
+  |122| 7 16  4.1|  6.4719  |+69 36 40 |   6.532  |17 vS E125 deg. D?        |
+  |123| 7 16  8.0|  6.4219  |+69 20  4 |   6.538  |18 vS E70 deg.            |
+  |124| 7 16 35.2|  6.4099  |+69 16 46 |   6.575  |16 vS iF              |
+  |125| 7 16 48.0|  6.4578  |+69 33 16 |   6.593  |17 vS R               |
+  |126| 7 17  9.1|  6.4119  |+69 18 25 |   6.622  |18 vS R               |
+  |127| 7 17 38.5|  6.4906  |+69 45 29 |   6.662  |17 vS bM R            |
+  |128| 7 17 45.3|  6.4750  |+69 40 36 |   6.672  |17 vS R bM            |
+  |129| 7 17 49.6|  3.7911  |+29 41 49 |   6.677  |18 vS F_{*}inv dif    |
+  |130| 7 17 49.7|  6.4843  |+69 43 46 |   6.678  |17 vS E135 deg. bM N      |
+  |   |          |          |          |          |  Spiral              |
+  |131| 7 18 11.1|  6.4754  |+69 41 28 |   6.707  |16 vS dif 2 or 3 N    |
+  |132| 7 18 14.4|  3.7838  |+29 27 41 |   6.711  |18 vS iF N            |
+  |133| 7 18 20.1|  3.7840  |+29 28 20 |   6.719  |18 vS bM              |
+  |134| 7 18 21.1|  3.7950  |+29 51 18 |   6.721  |18 vS bM              |
+  |135| 7 18 42.2|  3.7832  |+29 27 23 |   6.749  |18 vS iF sc           |
+  |136| 7 18 51.0|  6.6430  |+69 38 32 |   6.763  |17 vS E80 deg. bM N Spiral|
+  |   |          |          |          |          |  on edge             |
+  |137| 7 18 56.5|  3.7827  |+29 27  7 |   6.769  |19 vS                 |
+  |138| 7 19 10.0| +3.7819  |+29 26  7 | - 6.788  |18 vS R bM N Spiral?  |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |139| 7 19 11.6| +3.7800  |+29 22 12 | - 6.790  |18 vS bM              |
+  |140| 7 19 11.8|  6.4683  |+69 40 54 |   6.790  |15 vS Neb_{*}         |
+  |141| 7 19 25.2|  6.4609  |+69 38 50 |   6.809  |16 vS R bM N Spiral?  |
+  |142| 7 19 30.0|  3.7874  |+29 38 22 |   6.816  |18 vS 2N R            |
+  |143| 7 19 34.0|  6.4629  |+69 39 46 |   6.821  |17 vS R               |
+  |144| 7 19 46.5|  3.7859  |+29 35 58 |   6.839  |18 vS bM N R          |
+  |145| 7 19 48.3|  3.7866  |+29 37 21 |   6.841  |18 vS R bM            |
+  |146| 7 21 13.4|  6.4694  |+69 44 51 |   6.957  |17 vS R bM N Spiral?  |
+  |147| 7 21 57.9|  6.4648  |+69 44 42 |   7.018  |17 vS bM N R Spiral?  |
+  |148| 7 24  8.0|  5.8308  |+65 39 28 |   7.198  |pB E200 deg. bn           |
+  |149| 7 30 37.2|  5.8297  |+65 53 16 |   7.720  |vF vS                 |
+  |150| 7 31 10.9|  5.8139  |+65 47  0 |   7.767  |pB S gpmbM            |
+  |151| 8 32 38.8|  3.4536  |+19 56 37 |  12.387  |16 S E10 deg. stell N M   |
+  |   |          |          |          |          |  (Spiral on edge?)   |
+  |152| 8 32 40.2|  3.4534  |+19 56  0 |  12.388  |17 E95 deg. S dif         |
+  |153| 8 34 11.6|  3.4527  |+19 59 50 |  12.493  |17 vS E30 deg. stell N    |
+  |   |          |          |          |          |  Spiral?             |
+  |154| 8 35 28.9|  3.4520  |+20  2 47 |  12.581  |17 S Spiral N         |
+  |155| 8 36  7.4|  3.4514  |+20  3 33 |  12.624  |17 S R bM N           |
+  |156| 8 44 40.5|  3.7549  |+34 13 21 |  13.203  |eF E140 deg.              |
+  |157| 8 46  1.9|  3.7442  |+33 50 57 |  13.290  |vF vS                 |
+  |158| 8 46 26.8|  3.7403  |+33 44 26 |  13.318  |F vS N E120 deg. Spiral   |
+  |159| 8 46 52.6|  3.7397  |+33 45 19 |  13.345  |pB eS N R             |
+  |160| 8 47 20.6|  3.7507  |+34 14 43 |  13.376  |eF eS bf              |
+  |161| 8 47 56.9|  3.7509  |+34 18 41 |  13.415  |eeF                   |
+  |162| 9 12  0.0|  4.2083  |+51 47 20 |  14.898  |L 12 m E135 deg.          |
+  |163| 9 12  2.1|  4.2062  |+51 44 32 |  14.904  |16 E80 deg. bs S          |
+  |164| 9 12 12.5|  4.2001  |+51 36 54 |  14.910  |17 vS Ring bs         |
+  |165| 9 12 38.0|  4.1950  |+51 31 43 |  14.939  |16 E155 deg. gbm          |
+  |166| 9 12 40.4|  4.1862  |+51 18  0 |  14.936  |16 vS E15 deg. stell N    |
+  |167| 9 12 45.4|  4.1835  |+51 16 34 |  14.942  |16 E75 deg. vbN Spiral?   |
+  |168| 9 13 54.3|  4.1814  |+51 22 45 |  15.009  |18 vS N bM            |
+  |169| 9 14  0.5|  4.1839  |+51 26 53 |  15.016  |18 vS scNuclei        |
+  |170| 9 15 23.9|  4.1662  |+51 11 46 |  15.091  |17 vS R               |
+  |171| 9 15 24.6|  4.1652  |+51 10 12 |  15.091  |17 vS bN Ring or      |
+  |   |          |          |          |          |  Spiral              |
+  |172| 9 15 29.3|  4.1658  |+51 11 59 |  15.096  |17 S R                |
+  |173| 9 15 44.6|  4.1631  |+51 11 26 |  15.111  |15 B bM E145 deg.         |
+  |174| 9 16  6.3|  4.1821  |+51 42 11 |  15.136  |17 R S                |
+  |175| 9 16 14.6|  4.1638  |+51 15 42 |  15.142  |17 L vF bM            |
+  |176| 9 16 31.6|  4.1528  |+51 46 32 |  15.168  |17 R S bs             |
+  |177| 9 24 20.2|  3.4095  |+21 49 50 |  15.597  |vF vS                 |
+  |178| 9 24 36.8|  3.4084  |+21 48  6 |  15.612  |pB bs S               |
+  |179| 9 25 58.5|  3.4047  |+21 45 25 |  15.687  |eF E85 deg.               |
+  |180| 9 26 22.5|  3.4046  |+21 48 50 |  15.711  |pB S R gpmbM N        |
+  |181| 9 28  0.2|  3.4020  |+21 52 36 |  15.801  |eeF vS                |
+  |182| 9 41  3.6|  3.5855  |+33 58 24 |  16.474  |16 vS bM E75 deg.         |
+  |183| 9 41  9.9|  3.5850  |+33 58 12 |  16.480  |15 vS sbM Spiral      |
+  |184| 9 42  9.0|  3.5779  |+33 45 49 |  16.528  |17 vS N Spiral?       |
+  |185| 9 42 49.5|  3.5822  |+34  6 11 |  16.561  |16 vS bM              |
+  |186| 9 43 12.4|  3.5805  |+34  4 43 |  16.580  |15 vS sbM N Spiral    |
+  |187| 9 43 29.2|  3.5789  |+34  2 26 |  16.594  |16 vS bnw R           |
+  |188| 9 44 13.0|  3.5764  |+34  2  7 |  16.630  |14 vS bM N Spiral     |
+  |189| 9 44 24.6|  3.5760  |+34  3  1 |  16.640  |16 vS R N Spiral?     |
+  |190| 9 44 44.4|  3.5668  |+33 37 27 |  16.656  |17 vS E20 deg.            |
+  |191| 9 44 52.8|  5.0574  |+69 28 13 |  16.670  |pB vS R gpmbM         |
+  |192| 9 47  5.7|  4.9895  |+69  5 27 |  16.776  |pF S bf E90 deg.          |
+  |193| 9 47 22.2|  4.9858  |+69  5 25 |  16.790  |vF dif                |
+  |194| 9 50 19.4|  4.9915  |+69 30 40 |  16.930  |pF S E120 deg.            |
+  |195| 9 50 52.8|  4.9930  |+69 35 26 |  16.955  |eeF S E120 deg.           |
+  |196| 9 50 59.1|  5.0068  |+69 44  0 |  16.959  |pB S E50 deg. pmbM Spiral |
+  |197| 9 52 29.2|  4.9219  |+69  6 51 |  17.039  |eF E100 deg.              |
+  |198| 9 54  4.1|  4.1109  |+56  5 53 |  17.096  |11 vS neb_{*}         |
+  |199| 9 54 24.7|  4.1167  |+56 18 38 |  17.111  |18 vS R               |
+  |200| 9 54 26.5|  4.1121  |+56 11 53 |  17.113  |15 vS E95 deg. bM         |
+  |201| 9 55 14.0|  4.1162  |+56 27 13 |  17.148  |17 vS R               |
+  |202| 9 56 46.2|  4.0872  |+56  0 18 |  17.219  |17 vS R bM            |
+  |203| 9 57 29.5|  4.0952  |+56 20 33 |  17.250  |15 vS R N             |
+  |204|10  0 15.3|  2.9839  |- 7 33 34 |  17.372  |17 vS sbN Spiral      |
+  |205|10  0 40.4|  2.9909  |- 6 59 25 |  17.391  |17 vS stell sbN       |
+  |206|10  0 42.8|  2.9850  |- 7 29 50 |  17.392  |11 S D iF gbN bn      |
+  |207|10  1 49.7|  2.9891  |- 7 12 11 |  17.441  |17 vS stell           |
+  |208|10  6 50.1| +3.1101  |+ 3 50 57 | -17.653  |14 vS D neb_{*}       |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |209|10  7 18.1| +3.1112  |+ 4  5 30 | -17.671  |16 vS iF bM           |
+  |210|10  7 18.5|  3.1112  |+ 4  4 25 |  17.672  |16 vS bM N Spiral E50 deg.|
+  |211|10  7 58.4|  3.1128  |+ 3 58 44 |  17.699  |16 vS sbM N Spiral    |
+  |   |          |          |          |          |  E20 deg.                |
+  |212|10  8 20.6|  3.1137  |+ 3 52 13 |  17.714  |15 S iF bM            |
+  |213|10  9 40.7|  3.1169  |+ 4  8 34 |  17.769  |18 vS R               |
+  |214|10  9 44.8|  3.1171  |+ 4  9 47 |  17.772  |17 vS sbM N Spiral?   |
+  |   |          |          |          |          |  E45 deg.                |
+  |215|10  9 48.3|  3.6290  |+42  0 20 |  17.776  |16 E95 deg. 33'' long     |
+  |   |          |          |          |          |  small spur follows  |
+  |   |          |          |          |          |  E45 deg.                |
+  |216|10  9 50.2|  3.1172  |+ 4 10 50 |  17.776  |17 vS bM N R          |
+  |217|10  9 58.9|  3.6294  |+42  4  6 |  17.783  |17 vS R               |
+  |218|10 10  3.0|  3.6318  |+42 12 15 |  17.786  |17 vvS stell          |
+  |219|10 10 15.5|  3.6205  |+41 39 52 |  17.793  |15 S E60 deg.             |
+  |220|10 10 16.8|  3.6317  |+42 15 56 |  17.795  |vS R stell            |
+  |221|10 10 16.8|  3.6311  |+42 14  7 |  17.795  |18 vvS sbN Spiral?    |
+  |222|10 10 21.8|  3.1184  |+ 3 51 52 |  17.797  |17 vS bM N Spiral     |
+  |223|10 10 23.0|  3.6194  |+41 38 24 |  17.798  |16 vS bM Spiral N     |
+  |224|10 10 23.9|  3.6208  |+41 42 47 |  17.799  |18 vvS R Spiral? N    |
+  |225|10 10 24.5|  3.6206  |+41 42 41 |  17.800  |18 vvS sbN iF         |
+  |226|10 10 50.9|  3.6230  |+41 56 45 |  17.817  |18 vvS iF             |
+  |227|10 10 54.4|  3.6245  |+42  2 23 |  17.819  |17 vS iF              |
+  |228|10 11 44.0|  3.6222  |+42  7 31 |  17.852  |18 vvS bn iF          |
+  |229|10 11 44.0|  3.6221  |+42  7  3 |  17.852  |18 vvS Spiral sbN     |
+  |230|10 11 47.5|  3.6210  |+42  4 27 |  17.854  |17 vS sbN Spiral      |
+  |231|10 11 52.1|  3.6945  |+45 40 52 |  17.856  |F S R gbM bf          |
+  |232|10 11 52.2|  3.6214  |+42  6 56 |  17.857  |18 vvS iF stell       |
+  |233|10 12  6.2|  3.6114  |+41 36 50 |  17.861  |10 S neb_{*}          |
+  |234|10 12 21.8|  3.6231  |+42 19 55 |  17.878  |17 vS sbN Spiral      |
+  |235|10 12 29.1|  3.6192  |+42  8 54 |  17.882  |17 vS sbN Spiral      |
+  |236|10 12 31.5|  3.6204  |+42 13 16 |  17.883  |16 vS stell           |
+  |237|10 12 33.4|  3.6184  |+42  7 46 |  17.884  |18 vS E100 deg. Spiral?   |
+  |238|10 12 41.5|  3.6939  |+45 51 34 |  17.890  |eeeF??                |
+  |239|10 12 43.2|  3.6150  |+41 59  8 |  17.891  |17 vS sbM N           |
+  |240|10 12 43.5|  3.6168  |+42  5 16 |  17.891  |16 vvS bN stell       |
+  |241|10 12 48.1|  3.6940  |+45 53 41 |  17.894  |F vS R gbM            |
+  |242|10 12 50.6|  3.6940  |+45 54 11 |  17.896  |F S E90 deg.              |
+  |243|10 12 51.3|  3.6163  |+42  5 23 |  17.897  |18 vvS R stell        |
+  |244|10 12 57.8|  3.6136  |+41 58 39 |  17.901  |18 vvS iF             |
+  |245|10 13  0.4|  3.6212  |+42 23  5 |  17.902  |16 vS iB N Spiral E30 deg.|
+  |246|10 13  4.1|  3.6999  |+46 14 17 |  17.905  |B S E130 deg. Spiral on   |
+  |   |          |          |          |          |  edge                |
+  |247|10 13 10.1|  3.7010  |+46 18 50 |  17.909  |B R vm bM             |
+  |248|10 13 19.7|  3.6960  |+46  7 15 |  17.915  |eF S R bM             |
+  |249|10 13 33.8|  3.6170  |+42 17 28 |  17.924  |18 vS stell           |
+  |250|10 13 37.1|  3.6054  |+41 42 39 |  17.927  |17 vS Spiral stell N  |
+  |251|10 13 44.2|  3.6159  |+42 16 17 |  17.929  |17 vS R gbN           |
+  |252|10 13 46.0|  3.6110  |+42  1 15 |  17.933  |17 vvS gbN Spiral N   |
+  |253|10 13 48.5|  3.6972  |+46 17 57 |  17.934  |F S E170 deg. Spiral?     |
+  |254|10 13 53.9|  3.6036  |+41 41  1 |  17.938  |18 vS sbN             |
+  |255|10 13 54.5|  3.6107  |+42  3 31 |  17.938  |17 vS R gbN           |
+  |256|10 13 57.9|  3.6103  |+42  3  5 |  17.940  |17 vS iF gbN          |
+  |257|10 14  0.0|  3.6032  |+41 41  9 |  17.942  |18 vvS iF             |
+  |258|10 14  5.5|  3.6812  |+45 37  1 |  17.944  |vF vvS R              |
+  |259|10 14 11.5|  3.6113  |+42  9 10 |  17.949  |18 vvS bN Spiral      |
+  |260|10 14 12.5|  3.6113  |+42  9 44 |  17.949  |17 vS sbN Spiral      |
+  |261|10 14 24.2|  3.6104  |-42  9 42 |  17.958  |19 vvS iF E130 deg.       |
+  |262|10 14 26.8|  3.6865  |+45 57 27 |  17.958  |B S E45 deg.              |
+  |263|10 14 33.0|  3.6785  |+45 36 39 |  27.962  |vF vS E100 deg.           |
+  |264|10 14 35.7|  3.6250  |+42  0 31 |  17.965  |17 vS Spiral N E100 deg.  |
+  |265|10 14 46.3|  3.6916  |+46 16 40 |  17.972  |vvF E100 deg. spindle     |
+  |   |          |          |          |          |  shaped              |
+  |266|10 14 52.3|  3.6779  |+45 39 59 |  17.975  |vF S R                |
+  |267|10 15 22.5|  3.6866  |+46 11 40 |  17.995  |F R S gbM             |
+  |268|10 16 17.4|  3.6765  |+45 57  9 |  18.031  |F S R gbM             |
+  |269|10 16 27.1|  4.5844  |+68 53 10 |  18.038  |S pB bf               |
+  |270|10 16 37.1|  3.6761  |+46  1  1 |  18.044  |F pmbM E10 deg.           |
+  |271|10 17  8.0|  3.2872  |+20 19 46 |  18.062  |13 vS sbM N Spiral    |
+  |   |          |          |          |          |  E135 deg.               |
+  |272|10 17 12.7|  3.2868  |+20 18 16 |  18.065  |13 vS gbM Spiral      |
+  |273|10 17 19.6|  3.2865  |+20 17 47 |  18.070  |14 vS gbN             |
+  |274|10 17 47.1|  3.2899  |+20 40 58 |  18.087  |15 vS iF gbM          |
+  |275|10 17 53.6|  3.2880  |+20 31 57 |  18.091  |14 S sbM N Spiral     |
+  |   |          |          |          |          |  E130 deg.               |
+  |276|10 18  7.1|  3.2906  |+20 47 25 |  18.100  |13 vS sbM N Spiral    |
+  |277|10 19  5.2|  3.2870  |+20 38 42 |  18.136  |13 S sbM N Spiral     |
+  |278|10 19  6.9| +3.2857  |+20 32 21 | -18.137  |16 vS iF gbM          |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |279|10 19 10.3| +3.2885  |+20 47 38 | -18.139  |14 vS stell           |
+  |280|10 19 20.6|  4.5635  |+69  9 51 |  18.149  |S pF R                |
+  |281|10 24  6.2|  4.4863  |+68 59 31 |  18.317  |vS F E95 deg.             |
+  |282|11  1 52.7|  3.5701  |+55 59  0 |  19.407  |16 vS bN iF           |
+  |283|11  2  5.8|  3.5753  |+56 25 16 |  19.412  |15 vS neb_{*}         |
+  |284|11  2  9.5|  3.5660  |+55 53 31 |  19.413  |16 S gbM E100 deg.        |
+  |285|11  2 22.6|  3.5740  |+56 28 29 |  19.419  |15 vS stell           |
+  |286|11  2 54.6|  3.5647  |+56 11 43 |  19.429  |15 vS sbM stell N     |
+  |287|11  3  8.0|  3.5613  |+56  6 26 |  19.435  |17 vS N               |
+  |288|11  3 12.3|  3.5620  |+56 11 17 |  19.435  |16 vS sbN R Spiral?   |
+  |289|11  3 22.7|  3.5523  |+55 58 43 |  19.439  |14 vS neb_{*}         |
+  |290|11  4 32.2|  3.5510  |+56 12  9 |  19.463  |17 vS stell           |
+  |291|11  4 44.8|  3.5467  |+56  4  9 |  19.467  |15 S R sbM N Spiral   |
+  |292|11  4 47.7|  3.5469  |+56  5 40 |  19.468  |17 vS R neb_{*}       |
+  |293|11  4 57.3|  3.5437  |+55 59 16 |  19.471  |17 vS stell           |
+  |294|11  5  6.2|  3.5426  |+56  0 26 |  19.474  |Two 18 mag. objects,  |
+  |   |          |          |          |          |  iF, close together  |
+  |295|11  5 16.1|  3.5379  |+55 48 58 |  19.478  |16 vS. Uniform        |
+  |   |          |          |          |          |  brightness          |
+  |296|11  5 20.8|  3.5431  |+56  8 46 |  19.479  |17 vS iF stell        |
+  |297|11  5 22.1|  3.5373  |+55 49 20 |  19.480  |15 vS R gbM N Spiral  |
+  |298|11  5 35.2|  3.5408  |+56  8 18 |  19.484  |16 vS R gbM           |
+  |299|11  5 42.3|  3.5387  |+56  4 33 |  19.487  |18 vS sbM N Ring      |
+  |300|11  5 50.5|  3.5412  |+56 16 58 |  19.490  |17 vS sbM N Spiral?   |
+  |301|11  5 54.8|  3.5299  |+55 40 11 |  19.493  |vvF E75 deg.              |
+  |302|11  5 58.2|  3.5290  |+55 37 33 |  19.494  |S vF R                |
+  |303|11  6  1.6|  3.5352  |+56  1 39 |  19.494  |16 vS R sbM N Spiral  |
+  |304|11  6  6.1|  3.5322  |+55 53 51 |  19.495  |17 vS gbM iF          |
+  |305|11  6  8.8|  3.5347  |+56  3 23 |  19.496  |17 S vm E85 deg.          |
+  |306|11  6 12.5|  3.5292  |+55 45 22 |  19.499  |vF E100 deg. spindle      |
+  |   |          |          |          |          |  shaped              |
+  |307|11  6 19.1|  3.5312  |+55 56 37 |  19.500  |17 vS dif             |
+  |308|11  6 23.7|  3.5305  |+55 56 44 |  19.501  |vS iF dif             |
+  |309|11  6 27.1|  3.5300  |+55 56 40 |  19.502  |17 vS gbM iF          |
+  |310|11  6 28.4|  3.5303  |+55 58  4 |  19.503  |16 vS sbM N Spiral    |
+  |311|11  6 42.0|  3.5330  |+56 13 33 |  19.507  |16 vS bM E150 deg.        |
+  |312|11  6 43.0|  3.5297  |+56  3 13 |  19.508  |17 vS dif iF          |
+  |313|11  6 45.0|  3.5298  |+56  4 18 |  19.508  |17 vS dif iF          |
+  |314|11  6 51.1|  3.5313  |+56 12 24 |  19.510  |17 vS sbM N Spiral    |
+  |315|11  6 55.4|  3.5262  |+55 57 11 |  19.512  |16 vS R sbM N Spiral  |
+  |316|11  7  6.7|  3.5295  |+56 13 36 |  19.516  |13 S sbM N Spiral E70 deg.|
+  |317|11  7 10.+-|   ...    |+56 14  0+-|   ...    |16 vS stell iF neb?   |
+  |318|11  7 15.9|  3.5304  |+56 21  9 |  19.519  |15 vS R sbM N Spiral  |
+  |319|11  7 23.9|  3.5248  |+56  5 58 |  19.522  |15 vS neb_{*}         |
+  |320|11  7 32.4|  3.5239  |+56  7  1 |  19.525  |16 vS sbM N Spiral    |
+  |321|11  7 57.5|  3.5230  |+56 15 58 |  19.533  |16 vS gbM E25 deg.        |
+  |322|11  7 59.6|  3.5172  |+55 57 47 |  19.534  |16 vS neb_{*}         |
+  |323|11  8  1.8|  3.5117  |+55 36 17 |  19.534  |pB S R                |
+  |324|11  8  3.4|  3.5177  |+56  1 13 |  19.536  |16 vS sbM             |
+  |325|11  8  4.9|  3.5153  |+55 51 25 |  19.536  |S F gbM E100 deg.         |
+  |326|11  8 17.4|  3.5200  |+56 15 18 |  19.540  |12 S gbN be Spiral    |
+  |   |          |          |          |          |  E30 deg.                |
+  |327|11  8 25.0|  3.5178  |+56 12 21 |  19.543  |17 vS stell           |
+  |328|11  8 46.3|  3.5117  |+56  1 58 |  19.550  |15 vS stell N         |
+  |329|11  8 59.2|  3.5043  |+55 38 13 |  19.553  |pB S E160 deg.            |
+  |330|11  9 10.7|  3.5006  |+55 30 18 |  19.556  |B irr B_{*}n          |
+  |331|11  9 20.7|  3.5034  |+55 45 42 |  19.559  |vS B E100 deg. bM         |
+  |332|11  9 38.0|  3.4948  |+55 23 27 |  19.565  |S pF R another        |
+  |   |          |          |          |          |  apparently distinct |
+  |   |          |          |          |          |  neb np              |
+  |333|11  9 41.7|  3.5046  |+56  0  2 |  19.566  |L B pmbM R            |
+  |334|11  9 56.7|  3.4978  |+55 43 41 |  19.571  |vS B E135 deg. spindle    |
+  |   |          |          |          |          |  shaped              |
+  |335|11 10 14.5|  3.4873  |+55 14 57 |  19.578  |S B E90 deg. gbM          |
+  |336|11 10 28.9|  3.4870  |+55 19 48 |  19.581  |S pF E135 deg. companion n|
+  |337|11 10 43.8|  3.4929  |+55 49 55 |  19.587  |vS F E100 deg. bf         |
+  |338|11 10 58.5|  3.4913  |+55 14 50 |  19.592  |S B R vmbM            |
+  |339|11 11  1.0|  3.4817  |+55 17 47 |  19.593  |S B E45 deg. bsf          |
+  |340|11 11  4.2|  3.4809  |+55 16 23 |  19.594  |B Spiral              |
+  |341|11 11 36.5|  3.4780  |+55 21 45 |  19.604  |vvF S R               |
+  |342|11 12 23.8|  3.4719  |+55 23 11 |  19.619  |vB S e E170 deg.          |
+  |343|11 13 21.2|  3.1360  |+13 15 33 |  19.632  |B S R neb_{*}         |
+  |344|11 13 22.7|  3.1362  |+13 17 29 |  19.633  |S F gbM               |
+  |345|11 25 13.4|  3.2933  |+47 34  7 |  19.818  |S pB N                |
+  |346|11 26 40.5|  3.3848  |+47 39  8 |  19.836  |vS F                  |
+  |347|11 27  2.8|  3.2828  |+47 42 13 |  19.840  |vS F                  |
+  |348|11 27 10.3| +3.2774  |+47  2 45 | -19.842  |vS F gbM              |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |349|11 27 28.6| +3.2797  |+47 38 54 | -19.846  |vS B vmbM Spiral      |
+  |350|11 27 41.9|  3.2757  |+47 16 48 |  19.848  |vS B E135 deg.            |
+  |351|11 28 18.1|  3.2698  |+46 59 22 |  19.856  |vS F                  |
+  |352|11 28 50.2|  3.2694  |+47 24 46 |  19.862  |vS B                  |
+  |353|11 29 23.4|  3.2668  |+47 32 31 |  19.869  |vS vB N E100 deg.         |
+  |354|11 30  3.6|  3.2603  |+47 13 56 |  19.877  |pS pF                 |
+  |355|12 10 36.7|  3.0230  |+38 30 36 |  20.026  |S pB bf               |
+  |356|12 10 45.3|  3.0232  |+38  4 44 |  20.025  |S pB E95 deg.             |
+  |357|12 10 51.8|  3.0218  |+38 34  3 |  20.025  |S pB bf               |
+  |358|12 11 18.1|  2.9996  |+47 51 36 |  20.025  |15 vS stell           |
+  |359|12 11 27.3|  2.9987  |+47 49  2 |  20.024  |15 vS E135 deg. sbM N     |
+  |   |          |          |          |          |  Spiral              |
+  |360|12 11 46.7|  2.9956  |+48  6  2 |  20.022  |16 S E65 deg.             |
+  |361|12 11 48.5|  2.9961  |+47 55  0 |  20.022  |15 vS R sbM sN Spiral |
+  |362|12 11 50.1|  3.0176  |+38 27 34 |  20.021  |S vF                  |
+  |363|12 12  7.0|  2.9935  |+48  5 58 |  20.020  |15 vS R               |
+  |364|12 12 12.2|  3.0536  |+14 45 22 |  20.019  |17 vS R bM            |
+  |365|12 12 16.4|  3.0529  |+15 10 26 |  20.019  |18 vS R               |
+  |366|12 12 19.7|  3.0532  |+14 54  6 |  20.018  |18 vS R               |
+  |367|12 12 23.2|  3.0527  |+15 11 34 |  20.018  |18 vS vF dif          |
+  |368|12 12 23.5|  3.0535  |+14 39 45 |  20.018  |18 vS E160 deg.           |
+  |369|12 12 25.7|  3.0529  |+15  1 40 |  20.018  |18 vS R               |
+  |370|12 12 36.3|  2.9903  |+48  5 25 |  20.017  |16 vS dif vgbM        |
+  |371|12 12 42.0|  3.0529  |+14 45 51 |  20.016  |18 vS vF R            |
+  |372|12 12 44.4|  3.0530  |+14 38  8 |  20.016  |18 vS dif             |
+  |373|12 12 45.0|  3.0145  |+37 57  9 |  20.016  |S F R                 |
+  |374|12 12 45.6|  2.9909  |+47 38 17 |  20.016  |16 vS iF              |
+  |375|12 12 51.5|  3.0526  |+14 44 42 |  20.016  |18 vS R bs            |
+  |376|12 12 54.4|  2.9895  |+47 45 31 |  20.016  |17 vS iF dif          |
+  |377|12 12 54.6|  3.0523  |+14 54  0 |  20.015  |18 vS E110 deg.           |
+  |378|12 12 56.2|  3.0521  |+15  0  2 |  20.015  |17 vS R bM            |
+  |379|12 13  2.0|  3.0519  |+15  2 28 |  20.015  |17 vS R N             |
+  |380|12 13  5.6|  3.0515  |+15 15  4 |  20.014  |18 vS vF dif          |
+  |381|12 13  7.9|  3.0518  |+15  0  8 |  20.014  |18 vS R bM            |
+  |382|12 13  9.5|  3.0515  |+15 12 43 |  20.014  |17 vS R N             |
+  |383|12 13 13.1|  3.0120  |+38  6 46 |  20.014  |vS vF                 |
+  |384|12 13 30.1|  3.0108  |+38  4 43 |  20.013  |S F                   |
+  |385|12 13 33.8|  3.0108  |+37 57 29 |  20.013  |pL vF R               |
+  |386|12 13 36.6|  3.0510  |+15  4 41 |  20.012  |18 vS R               |
+  |387|12 13 37.3|  3.0514  |+14 47 32 |  20.012  |18 vS R N             |
+  |388|12 13 43.8|  3.0512  |+14 47 28 |  20.011  |18 vS R               |
+  |389|12 13 53.1|  3.0505  |+15  6 48 |  20.010  |18 vS E120 deg.           |
+  |390|12 13 53.6|  3.0506  |+15  4  0 |  20.010  |17 vS E100 deg. N         |
+  |391|12 13 57.4|  3.0505  |+15  3 34 |  20.010  |18 vS R N             |
+  |392|12 13 58.6|  3.0510  |+14 40 44 |  20.010  |19 vS vF              |
+  |393|12 14  5.2|  3.0508  |+14 41 10 |  20.009  |18 vS R bn            |
+  |394|12 14  6.2|  3.0502  |+15  5 31 |  20.009  |19 vS E110 deg. stell N   |
+  |395|12 14 12.7|  2.9815  |+47 38 45 |  20.009  |17 vS sbM Spiral      |
+  |396|12 14 22.8|  3.0497  |+15  8 31 |  20.008  |18 vS E130 deg.           |
+  |397|12 14 25.3|  3.0499  |+14 57 48 |  20.008  |17 vS R N             |
+  |398|12 14 31.1|  3.0497  |+14 58 50 |  20.007  |18 vS R               |
+  |399|12 14 44.0|  3.0496  |+14 50 50 |  20.006  |18 vS R N             |
+  |400|12 14 49.2|  3.0489  |+15 11 38 |  20.005  |18 vS vF              |
+  |401|12 15  4.9|  3.0490  |+14 53  4 |  20.004  |18 vS dif             |
+  |402|12 15  5.0|  3.0492  |+14 41 30 |  20.004  |18 vS R two N         |
+  |403|12 15 11.0|  3.0643  |+ 4 45 22 |  20.003  |pF vE15 deg.              |
+  |404|12 15 11.1|  3.0483  |+15 13 37 |  20.003  |17 vS E120 deg. bM        |
+  |405|12 15 22.7|  3.0482  |+15  6 45 |  20.002  |17 vS R               |
+  |406|12 15 31.2|  3.0484  |+14 47 34 |  20.002  |18 vS E150 deg.           |
+  |407|12 15 39.3|  3.0478  |+15 11 10 |  20.001  |18 vS R               |
+  |408|12 16 10.5|  3.0638  |+ 5 11 15 |  19.997  |F pS                  |
+  |409|12 16 12.4|  3.0647  |+ 4 37 52 |  19.997  |vF S bn               |
+  |410|12 16 31.2|  3.0438  |+16 32 16 |  19.995  |16 S E0 deg. sbM N Spiral |
+  |411|12 16 34.7|  3.0442  |+16 18  0 |  19.995  |16 S sbM stell N R    |
+  |   |          |          |          |          |  Spiral?             |
+  |412|12 16 36.7|  3.0442  |+16 13 30 |  19.994  |18 vS iF              |
+  |413|12 16 49.6|  3.0439  |+16 12  0 |  19.993  |17 vS gbM iF          |
+  |414|12 17  3.5|  3.0432  |+16 21 14 |  19.991  |18 S dif iF E135 deg.     |
+  |415|12 17  5.+-|  3.0446  |+15 56 30+-|  19.991  |17 vS sbM Spiral N    |
+  |416|12 17  5.2|  3.0431  |+16 23 20 |  19.991  |18 vs bs R            |
+  |417|12 17 12.1|  3.0638  |+ 4 50 23 |  19.991  |F vS l E50 deg.           |
+  |418|12 17 14.3| +3.0429  |+16 21 16 |  19.990  |17 vS dif gbM R       |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |419|12 17 15.6| +3.0430  |+16 17 18 | -19.990  |16S sbM N Spiral      |
+  |420|12 17 21.0|  3.0633  |+ 5  7 14 |  19.990  |! pB L Spiral         |
+  |421|12 17 29.5|  3.0639  |+ 4 41 53 |  19.989  |vF vS                 |
+  |422|12 17 37.0|  3.0639  |+ 4 41 13 |  19.989  |vF vS 1E45 deg.           |
+  |423|12 17 57.9|  3.0414  |+16 27 36 |  19.985  |17S gbM Spiral E135 deg.  |
+  |424|12 18  5.1|  3.0633  |+ 4 54 53 |  19.986  |vvF vs                |
+  |425|12 18 16.2|  3.0411  |+16 22 30 |  19.983  |15S sbM N Spiral?     |
+  |426|12 18 17.4|  3.0409  |+16 25 22 |  19.983  |18vS stell N Spiral   |
+  |427|12 18 19.3|  3.0629  |+ 5  0 40 |  19.983  |eeF S                 |
+  |428|12 18 34.6|  3.0352  |+18 54 45 |  19.981  |18vS R diffic         |
+  |429|12 18 40.4|  3.0352  |+18 49 41 |  19.980  |18vS vF E160''        |
+  |430|12 19 17.4|  3.0388  |+16 37 37 |  19.976  |17vS R gbN Spiral     |
+  |431|12 19 45.5|  3.0333  |+18 45  1 |  19.972  |15vS E45 deg. stell N     |
+  |432|12 20  0.7|  3.0399  |+16 15 57 |  19.971  |18 vS iF              |
+  |433|12 20  9.1|  3.0374  |+16 38 51 |  19.970  |17 S gbM N E60 deg. Spiral|
+  |   |          |          |          |          |  on edge             |
+  |434|12 20 10.9|  3.0372  |+16 40 27 |  19.970  |17 vS R sbM N Spiral  |
+  |435|12 20 21.3|  3.0322  |+18 41 40 |  19.968  |18 vS R bM            |
+  |436|12 20 21.8|  3.0369  |+16 40 40 |  19.968  |18 vS iF dif          |
+  |437|12 20 22.8|  3.0314  |+19  2 32 |  19.968  |18 vS R               |
+  |438|12 20 35.2|  3.0323  |+18 26 52 |  19.966  |18 vS R bM            |
+  |439|12 20 40.8|  3.0307  |+19  4 16 |  19.966  |18 vS vF R            |
+  |440|12 21 21.9|  3.0296  |+18 59 58 |  19.960  |18 vS R bM            |
+  |441|12 21 39.2|  3.0296  |+18 41 29 |  19.958  |18 vs R               |
+  |442|12 21 55.3|  3.0297  |+18 35 37 |  19.956  |17 vs R bM            |
+  |443|12 21 56.5|  3.0282  |+19  4 14 |  19.956  |18 vS R bM            |
+  |444|12 21 59.8|  3.0290  |+18 42  0 |  19.956  |18 vS E120 deg.           |
+  |445|12 22 13.3|  3.0282  |+18 49  7 |  19.954  |17 vS R bM            |
+  |446|12 25 24.7|  3.0336  |+14 42 46 |  19.924  |14 S E60 deg.             |
+  |447|12 25 35.6|  3.0320  |+15  8 33 |  19.922  |18 vS dif             |
+  |448|12 25 47.1|  3.0316  |+15 11 13 |  19.921  |15 vS bM iF           |
+  |449|12 25 49.9|  3.0317  |+15  6 17 |  19.920  |16 vS gbM             |
+  |450|12 25 53.0|  3.0312  |+15 19 36 |  19.920  |16 S E115 deg. bM         |
+  |451|12 26  0.9|  3.0320  |+14 54 29 |  19.918  |16 vS R               |
+  |452|12 26  0.9|  3.0308  |+15 20  0 |  19.918  |17 vS iF bM           |
+  |453|12 26  4.7|  3.0323  |+14 48 53 |  19.918  |18 vS iF              |
+  |454|12 26  8.1|  3.0319  |+14 55 14 |  19.917  |16 vS R sbM N         |
+  |455|12 26 12.2|  3.0322  |+14 44 59 |  19.916  |12 neb_{*}            |
+  |456|12 26 17.2|  3.0321  |+14 44 55 |  19.916  |16 vS iF gbM N        |
+  |457|12 26 17.3|  3.0323  |+14 40  6 |  19.916  |16 vS gbM N Spiral?   |
+  |458|12 26 34.7|  3.0299  |+15 24 49 |  19.913  |14 S bM E165 deg.         |
+  |459|12 26 51.1|  3.0308  |+14 51 34 |  19.910  |15 L m E80 deg. bM N      |
+  |   |          |          |          |          |  Spiral on edge      |
+  |460|12 27 26.5|  3.0636  |+ 3  8 36 |  19.904  |17 vS E80 deg. gbM Spiral |
+  |   |          |          |          |          |  on edge?            |
+  |461|12 27 30.4|  3.0634  |+ 3 12 55 |  19.903  |15 L vm E40 deg. small    |
+  |   |          |          |          |          |  spur from M         |
+  |462|12 27 31.7|  3.0290  |+15  7 56 |  19.903  |16 vS                 |
+  |463|12 27 31.8|  3.0623  |+ 3 34 13 |  19.903  |17 vS gbM iF          |
+  |464|12 27 39.2|  3.0304  |+14 36 16 |  19.902  |11 L bM iF sc         |
+  |465|12 27 41.6|  3.0299  |+14 44 55 |  19.902  |11 neb_{*}            |
+  |466|12 27 44.2|  3.0629  |+ 3 21  0 |  19.900  |17 vS vgbM iF         |
+  |467|12 27 45.0|  3.0634  |+ 3 10 55 |  19.900  |17 vS vgbM            |
+  |468|12 27 55.1|  3.0641  |+ 2 53 13 |  19.899  |18 vS R (Ring?)       |
+  |469|12 28 10.1|  3.0646  |+ 2 42  3 |  19.896  |17 vS R               |
+  |470|12 28 18.2|  3.0646  |+ 2 42 24 |  19.894  |16 vS [circle]        |
+  |471|12 28 26.5|  3.0648  |+ 2 50 47 |  19.893  |17 vS E150 deg.           |
+  |472|12 28 35.9|  3.0645  |+ 2 41 20 |  19.891  |17 vS E160 deg. N         |
+  |473|12 28 37.4|  3.0272  |+15 10 32 |  19.891  |16 vS sbM N Spiral    |
+  |   |          |          |          |          |  E50 deg.                |
+  |474|12 28 43.8|  3.0653  |+ 2 25 53 |  19.890  |16 vS gbM             |
+  |475|12 28 44.0|  3.0646  |+ 2 49 52 |  19.890  |17 vS R bM            |
+  |476|12 23 50.7|  3.0653  |+ 2 24 19 |  19.888  |18 vS vF R            |
+  |477|12 28 54.3|  3.0267  |+15 11 50 |  19.887  |18 vS sbM N Ring?     |
+  |478|12 28 55.5|  3.0656  |+ 2 19  2 |  19.887  |18 vS dif             |
+  |479|12 28 58.5|  3.0644  |+ 2 41 54 |  19.887  |18 vS E130 deg. N         |
+  |480|12 29  1.7|  3.0653  |+ 2 23 42 |  19.886  |17 vS R               |
+  |481|12 29  8.9|  3.0266  |+15  6 23 |  19.885  |16 vS sbM N Spiral    |
+  |482|12 29 15.8|  3.0614  |+ 3 39 39 |  19.883  |17 vS stell           |
+  |483|12 29 15.8|  3.0615  |+ 3 39 15 |  19.883  |18 vS N? Spiral?      |
+  |484|12 29 27.0|  3.0635  |+ 2 58  4 |  19.881  |18 vS dif iF          |
+  |485|12 29 28.7|  3.0636  |+ 3  7 14 |  19.881  |17 vS sbM N Spiral    |
+  |486|12 29 30.5|  3.0650  |+ 2 27 49 |  19.881  |17 vS R stell N       |
+  |487|12 29 40.8|  3.0616  |+ 3 33 41 |  19.879  |17 vS bM N Spiral     |
+  |488|12 29 42.7| +3.0635  |+ 2 55 34 | -19.879  |17 vS R               |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |489|12 29 45.4| +3.0650  |+ 2 26  4 | -19.878  |17 vS E90 deg. N          |
+  |490|12 29 51.4|  3.0620  |+ 3 24 29 |  19.877  |17 vS iF              |
+  |491|12 29 55.3|  3.0652  |+ 2 21  0 |  19.876  |17 vS R N             |
+  |492|12 29 56.6|  3.0632  |+ 3  0 22 |  19.876  |18 vS R N             |
+  |493|12 29 57.1|  3.0652  |+ 2 20 13 |  19.876  |17 vS R               |
+  |494|12 29 58.5|  3.0653  |+ 2 19 14 |  19.876  |18 vS R               |
+  |495|12 30  3.3|  2.9859  |+26 19 54 |  19.875  |15 vS R bM            |
+  |496|12 30  4.2|  3.0652  |+ 2 20  7 |  19.875  |18 vS R               |
+  |497|12 30  6.6|  3.0616  |+ 3 33  6 |  19.874  |17 vS bs iF           |
+  |498|12 30 11.2|  3.0616  |+ 3 30 36 |  19.873  |17 vS stell           |
+  |499|12 30 12.4|  3.0649  |+ 2 25  7 |  19.873  |18 vS R               |
+  |500|12 30 12.8|  2.9853  |+26 22 24 |  19.873  |17 VS R bM            |
+  |501|12 30 14.8|  3.0648  |+ 2 26 29 |  19.873  |18 vS E70 deg.            |
+  |502|12 30 27.3|  3.0648  |+ 2 26 16 |  19.870  |18 vS R bM            |
+  |503|12 30 28.4|  3.0648  |+ 2 26 41 |  19.870  |17 vS R bM            |
+  |504|12 30 29.0|  3.0651  |+ 2 19 36 |  19.870  |16 vS R               |
+  |505|12 30 30.6|  3.0613  |+ 3 35  6 |  19.870  |15 L vm E165 deg. sbM     |
+  |   |          |          |          |          |  Spiral              |
+  |506|12 30 32.2|  3.0650  |+ 2 22 17 |  19.869  |18 vS R bM            |
+  |507|12 30 35.8|  3.0642  |+ 2 37 39 |  19.869  |18 vS R               |
+  |508|12 30 36.8|  2.9840  |+26 24  5 |  19.868  |14 S E135 deg. N          |
+  |509|12 30 39.5|  3.0643  |+ 2 34 35 |  19.868  |18 vS R               |
+  |510|12 30 39.7|  3.0645  |+ 2 29 55 |  19.868  |18 vS R               |
+  |511|12 30 42.6|  3.0648  |+ 2 25 14 |  19.867  |18 vS R bM            |
+  |512|12 30 43.7|  2.9819  |+26 50 17 |  19.867  |17 vS E40 deg.            |
+  |513|12 30 44.2|  2.9822  |+26 46 25 |  19.867  |15 vS N E50 deg.          |
+  |514|12 30 52.0|  3.0648  |+ 2 22 56 |  19.866  |17 vS R               |
+  |515|12 30 52.6|  3.0619  |+ 3 19 59 |  19.866  |17 vS sbM Spiral E110 deg.|
+  |516|12 31 22.5|  2.9809  |+26 38  7 |  19.859  |18 vS R               |
+  |517|12 31 32.7|  2.9797  |+26 47 58 |  19.857  |18 vS R               |
+  |518|12 31 39.6|  2.9794  |+26 47  9 |  19.856  |16 vS R N             |
+  |519|12 31 46.1|  2.9796  |+26 39 51 |  19.855  |17 vS R N             |
+  |520|12 32  6.9|  2.9787  |+26 38 28 |  19.850  |17 vS R N             |
+  |521|12 32 21.2|  2.9784  |+26 31 56 |  19.848  |18 vS vF R            |
+  |522|12 32 22.7|  2.9777  |+26 42 36 |  19.847  |18 vS R bM            |
+  |523|12 22 29.7|  2.9777  |+26 37 36 |  19.846  |18 vS R bM            |
+  |524|12 32 34.2|  2.9780  |+26 28 24 |  19.845  |16 neb_{*}            |
+  |525|12 32 49.7|  2.9758  |+26 50 59 |  19.842  |18 vS vF E135 deg. D      |
+  |526|12 35 41.0|  2.9371  |+33  7 48 |  19.805  |16 vS E140 deg. bM        |
+  |527|12 36 34.4|  2.9348  |+32 56 17 |  19.792  |17 vS R bM            |
+  |528|12 36 45.3|  2.9340  |+32 56 48 |  19.790  |18 vS E80 deg.            |
+  |529|12 36 54.9|  2.9309  |+33 24 23 |  19.787  |17 vS E0 deg. D           |
+  |530|12 37 14.3|  2.9303  |+33 18 35 |  19.781  |15 vS E125 deg. N Spiral  |
+  |   |          |          |          |          |  on edge             |
+  |531|12 38  9.9|  2.9291  |+32 52 38 |  19.770  |18 vS bM E140 deg.        |
+  |532|12 38 13.8|  2.9277  |+33  6 12 |  19.769  |18 vS R               |
+  |533|12 38 15.0|  2.9279  |+33  2 21 |  19.768  |14 vS E145 deg. bM        |
+  |534|12 38 33.3|  2.9247  |+33 26  3 |  19.764  |15 neb_{*}            |
+  |535|12 38 35.6|  2.9268  |+33  0 52 |  19.764  |16 neb_{*}            |
+  |536|12 38 41.7|  2.9267  |+32 56 47 |  19.762  |18 vS R               |
+  |537|12 38 45.4|  2.9259  |+33  2 53 |  19.761  |18 vS R               |
+  |538|12 44  9.3|  2.8448  |+41 38 45 |  19.677  |18 vS R N             |
+  |539|12 44 30.5|  2.8431  |+41 38 16 |  19.670  |15 vS E60 deg. Spiral?    |
+  |540|12 44 31.8|  2.8425  |+41 41 45 |  19.670  |18 vS vR dif          |
+  |541|12 44 36.3|  2.8424  |+41 39 31 |  19.669  |18 vS vF R diffic     |
+  |542|12 44 39.0|  2.8418  |+41 41 51 |  19.668  |18 vS R diffic        |
+  |543|12 44 46.6|  2.8401  |+41 49 26 |  19.666  |17 vS R bM            |
+  |544|12 44 46.9|  2.9440  |+26 19  4 |  19.666  |16 vS E60 deg. bM         |
+  |545|12 44 47.5|  2.8417  |+41 23 51 |  19.666  |18 vS R bM            |
+  |546|12 44 52.4|  2.8423  |+41 30 43 |  19.664  |17 vS R               |
+  |547|12 44 55.4|  2.8398  |+41 46 30 |  19.663  |18 vS vF R diffic     |
+  |548|12 44 56.5|  2.8426  |+41 25 53 |  19.663  |18 vS R               |
+  |549|12 45  8.4|  2.8376  |+41 54 40 |  19.659  |18 vS vF dif D?       |
+  |550|12 45 16.5|  2.8412  |+41 23 26 |  19.657  |16 vS E80 deg. bM Spiral? |
+  |551|12 45 16.9|  2.9453  |+25 50  0 |  19.657  |17 vS R bM            |
+  |552|12 45 21.5|  2.8404  |+41 26  8 |  19.656  |16 vS R bM            |
+  |553|12 45 27.0|  2.8395  |+41 29 21 |  19.654  |18 vS vF E150 deg. bM     |
+  |   |          |          |          |          |  Spiral on edge      |
+  |554|12 45 28.2|  2.9448  |+25 50 38 |  19.654  |18 vS R               |
+  |555|12 45 29.3|  2.9442  |+26 13 28 |  19.653  |17 vS E50 deg. bs         |
+  |556|12 45 30.5|  2.9444  |+26 14 10 |  19.653  |17 vS R               |
+  |557|12 45 43.2|  2.8361  |+41 44 11 |  19.649  |17 vS R N             |
+  |558|12 45 56.5|  2.9436  |+25 49 14 |  19.646  |16 vS E40 deg. N          |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |559|12 45 58.3| +2.9436  |+25 48 13 | -19.645  |16 vS E35 deg. N          |
+  |560|15 45 59.1|  2.8368  |+41 29 16 |  19.645  |18 vS vF R            |
+  |561|12 46 10.3|  2.8363  |+41 25 57 |  19.641  |18 vS vF R bM         |
+  |562|12 46 22.3|  2.8331  |+41 56  7 |  19.638  |15 vS E90 deg. bs Spiral? |
+  |563|12 46 22.8|  2.8358  |+41 22 17 |  19.638  |18 vS vF R [circle]?  |
+  |564|12 46 26.4|  2.8328  |+41 41 43 |  19.637  |17 vS R bM            |
+  |565|12 46 26.6|  2.8335  |+41 35 39 |  19.637  |18 vS R bM            |
+  |566|12 46 37.8|  2.8325  |+41 36  5 |  19.633  |18 vS R bM            |
+  |567|12 46 46.6|  2.9393  |+26  9 36 |  19.631  |16 vS E150 deg. bM        |
+  |568|12 47  5.2|  2.8321  |+41 22 31 |  19.625  |18 vS R               |
+  |569|12 47 13.3|  2.8269  |+41 54 46 |  19.623  |17 vS R bM            |
+  |570|12 47 14.6|  2.8309  |+41 24 52 |  19.622  |17 vS R bM            |
+  |571|12 47 24.3|  2.8272  |+41 46 30 |  19.620  |18 vS R bM            |
+  |572|12 47 29.8|  2.8254  |+41 56  1 |  19.618  |18 vS R               |
+  |573|12 47 31.6|  2.9395  |+25 45  4 |  19.618  |16 vS E10 deg. N          |
+  |574|12 47 38.9|  2.8258  |+41 47 20 |  19.615  |18 vS R N             |
+  |575|12 47 43.7|  2.8260  |+41 42 48 |  19.614  |18 vS R bM            |
+  |576|12 47 53.5|  2.8245  |+41 48 10 |  19.611  |18 vS dif             |
+  |577|12 48  1.6|  2.8256  |+41 34 23 |  19.609  |16 vS E125 deg. bM        |
+  |578|12 48 17.5|  2.8252  |+41 27 34 |  19.604  |18 vS R               |
+  |579|12 48 25.4|  2.8217  |+41 48 40 |  19.602  |18 vS vF R            |
+  |580|12 48 30.9|  2.8246  |+41 23 31 |  19.600  |17 vS R N             |
+  |581|12 48 31.3|  2.8206  |+41 53 17 |  19.600  |18 vS vF R            |
+  |582|12 48 32.9|  2.8244  |+41 23 30 |  19.600  |16 vS R N             |
+  |583|12 50 50.7|  2.9509  |+22 25 55 |  19.557  |S R vF                |
+  |584|12 51 15.7|  2.9504  |+22 21  0 |  19.549  |vS vF E90 deg.            |
+  |585|13  9 17.4|  2.7068  |+42 33 56 |  19.139  |18 vS R               |
+  |586|13  9 24.6|  2.7039  |+42 44 21 |  19.135  |14 S E150 deg. four N     |
+  |587|13  9 25.1|  2.7071  |+42 30  1 |  19.135  |18 vS R               |
+  |588|13  9 30.5|  2.7093  |+42 18  5 |  19.133  |17 vS R bM            |
+  |589|13  9 35.1|  2.7083  |+42 20 47 |  19.131  |17 vS R bM            |
+  |590|13  9 36.1|  2.7089  |+42 17 28 |  19.130  |17 vS R bM            |
+  |591|13  9 38.6|  2.7084  |+42 19  5 |  19.129  |18 vS R bM            |
+  |592|13  9 43.4|  2.7086  |+42 15 56 |  19.127  |18 vS R               |
+  |593|13  9 46.8|  2.7056  |+42 28 13 |  19.125  |17 vS E120 deg.           |
+  |594|13  9 47.8|  2.7078  |+42 18  1 |  19.125  |16 vS E150 deg. bM        |
+  |595|13  9 53.2|  2.7077  |+42 16 31 |  19.123  |18 vS R bM            |
+  |596|13  9 53.3|  2.7086  |+42 12 19 |  19.123  |18 vS vF R            |
+  |597|13  9 56.2|  2.7042  |+42 28 40 |  19.121  |16 vS E90 deg. bM         |
+  |598|13  9 57.3|  2.7028  |+42 36 34 |  19.121  |18 vS R               |
+  |599|13 10  1.3|  2.7084  |+42 10 13 |  19.119  |14 vS E15 deg. gbM        |
+  |600|13 10  4.6|  2.7015  |+42 40  5 |  19.117  |18 vS R               |
+  |601|13 10  5.4|  2.6999  |+42 47 12 |  19.117  |16 vS R bM neb_{*}?   |
+  |602|13 10  5.7|  2.7054  |+42 22 10 |  19.117  |18 vS R               |
+  |603|13 10  5.8|  2.7061  |+42 18 47 |  19.117  |17 vS R bM            |
+  |604|13 10  5.8|  2.7014  |+42 37 56 |  19.117  |18 vS R N             |
+  |605|13 10  7.0|  2.7032  |+42 31 16 |  19.116  |17 vS E165 deg. gbM       |
+  |606|13 10 11.5|  2.7018  |+42 35 45 |  19.114  |18 vS R bM            |
+  |607|13 10 11.7|  2.7030  |+42 30 44 |  19.114  |18 vS E50 deg.            |
+  |608|13 10 12.4|  2.7030  |+42 30  7 |  19.114  |18 vS R               |
+  |609|13 10 12.8|  2.7009  |+42 39 44 |  19.114  |18 vS R               |
+  |610|13 10 14.1|  2.7027  |+42 31  8 |  19.113  |18 vS R vF            |
+  |611|13 10 16.2|  2.7027  |+42 30 10 |  19.112  |18 vS E70 deg. bM         |
+  |612|13 10 21.0|  2.7057  |+42 14 33 |  19.110  |14 neb_{*}            |
+  |613|13 10 22.6|  2.7064  |+42 10 52 |  19.110  |18 vS vF R            |
+  |614|13 10 31.3|  2.7009  |+42 32 28 |  19.105  |17 vS R bM            |
+  |615|13 10 32.5|  2.6979  |+42 45 51 |  19.105  |18 vS R               |
+  |616|13 10 38.2|  2.7026  |+42 22 18 |  19.102  |18 vS R bM            |
+  |617|13 10 38.9|  2.7042  |+42 14 22 |  19.102  |18 vS R               |
+  |618|13 10 41.2|  2.7033  |+42 17 50 |  17.101  |17 vS E150 deg. gbM       |
+  |619|13 10 43.5|  2.7016  |+42 24 33 |  19.100  |18 vS E80 deg.            |
+  |620|13 10 47.8|  2.7041  |+42 11 39 |  19.098  |18 vS vF R            |
+  |621|13 10 51.4|  2.6951  |+42 51 13 |  19.096  |16 vS E75 deg. gbM        |
+  |622|13 10 53.8|  2.6947  |+42 52  3 |  19.095  |17 vS E150 deg. bM        |
+  |623|13 10 57.6|  2.7032  |+42 11 42 |  19.094  |18 vS R               |
+  |624|13 10 58.1|  2.7007  |+42 22 50 |  19.094  |17 vS R bM            |
+  |625|13 11  3.2|  2.7008  |+42 20 46 |  19.091  |18 vS R               |
+  |626|13 11  5.9|  2.7011  |+42 17 58 |  19.090  |18 vS E30 deg.            |
+  |627|13 11  8.3|  2.7022  |+42 12 22 |  19.089  |17 vS R bM            |
+  |628|13 11  9.6| +2.7002  |+42 20 44 | -19.088  |18 vS vF R            |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |629|13 11 15.1| +2.7001  |+42 19  9 | -19.086  |18 vS R bM            |
+  |630|13 11 19.7|  2.7017  |+42 10  0 |  19.084  |18 vS E35 deg.            |
+  |631|13 11 21.3|  2.6978  |+42 27 13 |  19.083  |17 vS E100 deg. bM        |
+  |632|13 11 27.5|  2.6973  |+42 27  7 |  19.080  |17 vS E60 deg. gbM        |
+  |633|13 11 29.8|  2.6982  |+42 22 18 |  19.079  |18 vS R               |
+  |634|13 11 30.7|  2.6978  |+42 23 27 |  19.079  |17 vS E75 deg.            |
+  |635|13 11 36.8|  2.6985  |+42 17 58 |  19.076  |17 vS R N             |
+  |636|13 11 38.3|  2.6935  |+42 40 21 |  19.075  |18 vS R               |
+  |637|13 11 38.6|  2.6973  |+42 22 44 |  19.075  |18 vS E110 deg.           |
+  |638|13 11 40.2|  2.6925  |+42 43 58 |  19.075  |18 vS E125 deg.           |
+  |639|13 11 43.0|  2.6960  |+42 27  5 |  19.073  |17 vS E130 deg. gbM       |
+  |640|13 11 44.1|  2.6972  |+42 21 11 |  19.073  |18 vS R               |
+  |641|13 11 50.0|  2.6933  |+42 36 47 |  19.070  |17 vS R bM            |
+  |642|13 11 51.6|  2.6967  |+42 20 17 |  19.070  |17 vS R bM            |
+  |643|13 11 53.9|  2.6963  |+42 21 24 |  19.068  |18 vS R bM            |
+  |644|13 11 54.9|  2.6964  |+42 20 41 |  19.068  |18 vS R bM            |
+  |645|13 11 57.0|  2.6963  |+42 20  7 |  19.067  |17 vS E110 deg. gbM       |
+  |646|13 11 58.6|  2.6949  |+42 25 54 |  19.066  |18 vS R               |
+  |647|13 12 15.4|  2.6903  |+42 40 36 |  29.0S9  |18 vS R               |
+  |648|13 12 24.1|  2.6907  |+42 35 22 |  19.055  |17 vS R N             |
+  |649|13 12 29.4|  2.6861  |+42 54 15 |  19.053  |17 vS E130 deg.           |
+  |650|13 12 37.4|  2.6880  |+42 42 38 |  19.049  |16 vS R bM neb_{*}?   |
+  |651|13 12 38.9|  2.6893  |+42 35 47 |  19.048  |18 vS R               |
+  |652|13 12 39.7|  2.6862  |+42 49 45 |  19.048  |27 vS E45 deg.            |
+  |653|13 12 44.7|  2.6885  |+42 37 23 |  19.046  |18 vS R               |
+  |654|13 12 56.6|  2.6872  |+42 38 34 |  19.040  |18 vS R               |
+  |655|13 13  4.2|  2.6861  |+42 40 46 |  19.037  |18 vS R               |
+  |656|13 13 11.7|  2.6913  |+42 13 29 |  19.033  |17 vS R bM            |
+  |657|13 13 11.8|  2.6850  |+42 42 56 |  19.033  |18 vS vF dif          |
+  |658|13 13 19.6|  2.6877  |+42 27 12 |  19.030  |18 vS E160 deg.           |
+  |659|13 13 21.4|  2.6829  |+42 48 36 |  19.029  |18 vS R               |
+  |660|13 13 22.0|  2.6878  |+42 25 44 |  19.029  |18 vS R               |
+  |661|13 13 22.8|  2.6837  |+42 44 34 |  19.029  |17 vS R N             |
+  |662|13 13 28.2|  2.6825  |+42 47 49 |  19.026  |18 vS vF R            |
+  |663|13 13 36.3|  2.6830  |+42 42  9 |  19.023  |17 vS R bM            |
+  |664|13 13 57.0|  2.6802  |+42 47  4 |  19.014  |18 vS R               |
+  |665|13 14  2.4|  2.6802  |+42 44 54 |  19.011  |17 vS R bM            |
+  |666|13 23  5.2|  2.5574  |+47 23  8 |  18.746  |vS eeF                |
+  |667|13 24 19.1|  2.5489  |+47 26 42 |  18.707  |B pL E80 deg.             |
+  |668|13 26  4.1|  2.5313  |+47 49 42 |  18.651  |vS eF                 |
+  |669|13 26 15.2|  2.5313  |+47 45 47 |  18.644  |S pB l E135 deg.          |
+  |670|13 27  7.8|  2.5273  |+47 41 54 |  18.616  |S eeF                 |
+  |671|23 27 19.5|  2.5333  |+47 18 40 |  18.610  |F S R                 |
+  |672|23 27 33.2|  2.5315  |+47 20 14 |  18.602  |vS vF E90 deg.            |
+  |673|13 31 34.8|  3.2319  |-17  4 23 |  18.468  |16 vS E150 deg.           |
+  |674|13 31 38.8|  3.2351  |-17 22  4 |  18.466  |16 vS E150 deg. bM        |
+  |675|13 31 47.9|  3.2332  |-17  9 33 |  18.460  |18 vS R               |
+  |676|13 31 52.4|  3.2335  |-17 10 52 |  18.458  |18 vS E50 deg.            |
+  |677|13 31 52.5|  3.2339  |-17 12 47 |  18.458  |18 vS bn dif          |
+  |678|13 32 54.9|  3.2386  |-17 29 57 |  18.422  |17 vS bM E105 deg.        |
+  |679|13 57 42.5|  2.1379  |+54 54  5 |  17.461  |B S E90 deg. neb_{*}?     |
+  |680|14  1 50.9|  2.1136  |+54 44 50 |  17.280  |S pF bp               |
+  |681|14  2  3.1|  2.1055  |+54 56 17 |  17.272  |pB L i                |
+  |682|15  0  8.1|  1.6712  |+55 59  2 |  14.170  |18 vS R bM            |
+  |683|15  0 32.4|  1.6694  |+55 58 21 |  14.144  |18 vS vF E110 deg.        |
+  |684|15  0 33.7|  1.6634  |+56  4 52 |  14.143  |17 vS E160 deg.           |
+  |685|15  1  2.9|  1.6722  |+55 51 53 |  14.113  |17 vS R bM            |
+  |686|25  1  4.1|  1.6638  |+56  0 58 |  14.111  |17 vS R bM            |
+  |687|15  1 30.4|  2.7322  |+19 40 56 |  14.082  |S R F                 |
+  |688|15  1 32.3|  2.7225  |+20 11 15 |  14.080  |S pF E45 deg.             |
+  |689|25  1 37.2|  2.7251  |+20  3  1 |  14.075  |vS F E10 deg.             |
+  |690|15  2 31.5|  1.6443  |+56 12 53 |  14.018  |16 vS R bM            |
+  |691|15  2 49.2|  2.7273  |+19 49 56 |  13.999  |pS F gbM              |
+  |692|15  2 59.6|  1.6345  |+56 20 44 |  13.989  |17 vS R bs            |
+  |693|25  3 18.1|  1.6535  |+55 57 34 |  13.970  |13 neb_{*}            |
+  |694|15  3 29.0|  2.7243  |+19 56 29 |  13.958  |vF S R                |
+  |695|25  3 30.9|  1.6493  |+56  0 49 |  13.956  |16 vS N E105 deg.         |
+  |696|15  3 34.9|  2.7213  |+20  5 39 |  13.952  |vS F E45 deg.             |
+  |697|15  3 40.9|  2.7207  |+20  7  7 |  13.946  |vF pL Spiral          |
+  |698|15  3 47.8| +1.6564  |+55 51  5 | -13.939  |17 vS E45 deg.            |
+  +----------------------------------------------------------------------+
+
+  +----------------------------------------------------------------------+
+  |No.|[Greek: a]|Precession|[Greek: d]|Precession|    Description.      |
+  |   |  1900.0  |          |  1900.0  |          |                      |
+  |----------------------------------------------------------------------|
+  |   |h  m    s |     s    |  deg.  '  '' |     ''   |                      |
+  |699|15  3 54.2| +1.6479  |+55 59 40 | -13.932  |17 vS bM E135 deg.        |
+  |700|15  3 56.8|  2.7242  |+19 54 41 |  13.929  |vS F                  |
+  |701|15  4 23.7|  2.7281  |+19 40 23 |  13.901  |F pL gbM Spiral?      |
+  |702|15  4 28.2|  2.7248  |+19 50 25 |  13.896  |pB S E90 deg.             |
+  |703|15  4 31.9|  1.6563  |+55 46  6 |  13.892  |18 vS E35 deg.            |
+  |704|15  5 45.5|  1.6277  |+56 20 45 |  13.815  |17 vS R N             |
+  |705|15  5 52.1|  1.6401  |+55 55  5 |  13.807  |18 vS R N             |
+  |706|15  6 37.4|  1.6263  |+56  5 17 | -13.760  |18 vS R bM            |
+  |707|22 29 41.0|  2.7214  |+34 22 53 | +18.513  |F S E90 deg.              |
+  |708|22 30 38.1|  2.7299  |+33 58 36 |  18.544  |F S R                 |
+  |709|22 30 54.8|  2.7306  |+34  0 21 |  18.552  |F pS vmbM             |
+  |710|22 31  3.1|  2.7344  |+33 44 58 |  18.557  |pB vS m E90 deg. vmbM     |
+  |711|22 31 17.6|  2.7303  |+34  8 35 |  18.566  |vF vS m E160 deg.         |
+  |712|22 31 43.9|  2.7334  |+34  1 32 |  18.579  |F pL i_{*} inv        |
+  |713|22 32  1.5|  2.7394  |+33 42 15 |  18.588  |vF S m E140 deg.          |
+  |714|22 32 29.8|  2.7324  |+34 19 13 |  18.603  |pB vS gmbM            |
+  |715|22 32 33.2|  2.7354  |+34  6  5 |  18.605  |vF pL gbM             |
+  |716|22 32 46.2|  2.7393  |+33 51 20 |  18.612  |D_{*} inv set on p_{*}|
+  |717|22 32 50.3|  2.7347  |+34 13 53 |  18.614  |pB S E0 deg. vmbM         |
+  |718|22 33  1.3|  2.7406  |+34 19 38 |  18.620  |vB S l E50 deg. vmbM      |
+  |719|22 33 37.7|  2.7361  |+34 21  1 |  18.640  |pF pL l E90 deg.          |
+  |720|22 33 50.5|  2.7448  |+33 43 16 |  18.647  |Neb_{*}               |
+  |721|22 33 58.1|  2.7410  |+34  4  9 |  18.651  |vF pS E45 deg.            |
+  |722|22 34  0.6|  2.7442  |+33 49  6 |  18.652  |F S E20 deg.              |
+  |723|22 34 10.8|  2.7453  |+33 46 59 |  18.658  |F pL gbM              |
+  |724|23  8 29.3|  3.0514  |+ 4  0 38 |  19.543  |B vS E135 deg.            |
+  |725|23  8 49.6|  3.0499  |+ 4 20 26 |  19.549  |vvF S R               |
+  |726|23  9 42.0|  3.0515  |+ 4  5 43 |  19.566  |B S vE 170 deg.           |
+  |727|23 10  1.1|  3.0529  |+ 3 49 42 |  19.572  |B S neb_{*}           |
+  |728|23 10 24.4|  3.0504  |+ 4 21 20 |  19.580  |B neb_{*}             |
+  |729|23 10 28.1|  3.0501  |+ 4 25 14 |  19.581  |pS vF i               |
+  |730|23 11 11.5|  3.0521  |+ 4  5 19 |  19.594  |S l E90 deg.              |
+  |731|23 47  4.6|  3.0620  |+ 7 50 21 |  20.016  |F pL N Spiral?        |
+  |732|23 48 15.7|  3.0632  |+ 7 35 32 |  20.021  |vF BN E100 deg. Spiral    |
+  |733|23 49 39.3|  3.0640  |+ 7 49 26 |  20.027  |F vS mbM l E45 deg.       |
+  |734|23 56 13.3|  3.0661  |+15 55 34 |  20.045  |vvF vS                |
+  |735|23 56 16.0|  3.0663  |+15 43 36 |  20.045  |pB vS                 |
+  |736|23 56 36.9|  3.0668  |+15 45 12 |  20.045  |F vS                  |
+  |737|23 56 40.1|  3.0669  |+15 45 59 |  20.045  |F vS E60 deg.             |
+  |738|23 56 52.9|  3.0657  |+20 25 57 |  20.046  |S vF F_{*} sp         |
+  |739|23 57  4.8|  3.0676  |+15 49  9 |  20.046  |vF pS                 |
+  |740|23 58  4.0|  3.0692  |+15 24 34 |  20.046  |B m E135 deg. N           |
+  |741|23 58 18.1|  3.0686  |+20 47  8 |  20.047  |vS vF E45 deg.            |
+  |742|23 58 53.3|  3.0705  |+15 27 48 |  20.047  |F vS                  |
+  |743|23 59 20.8|  3.0713  |+15 25 32 |  20.047  |vvF vS                |
+  |744|23 59 23.2| +3.0710  |+20  9 40 | +20.047  |S F E170 deg.             |
+  +----------------------------------------------------------------------+
+
+
+ABBREVIATIONS USED IN DESCRIPTION.
+
+The number denotes magnitude,--estimated from the negative.
+
+  vS       very small, <30''
+  S        small, 30'' to 2' or 3'
+  L        large, >2' or 3'
+  B        bright
+  D        double
+  E        elongated
+  F        faint
+  iF       irregular figure
+  M        middle or in the middle
+  N        nucleus
+  R        round
+  b        brighter
+  bn       brighter toward the north side
+  bs       brighter toward the south side
+  bp       brighter toward the preceding side
+  bf       brighter toward the following side
+  bsw      brightest toward the south-west
+  bM       brighter toward the middle
+  dif      diffused
+  diffic   difficult
+  eF       extremely faint
+  g        gradually
+  i        irregular
+  l        little
+  m        much
+  p        pretty
+  pB       pretty bright
+  pF       pretty faint
+  sc       scattered
+  stell    stellar
+  sbM      suddenly brighter toward the middle
+  v        very
+  vbM      very much brighter toward the middle
+  vS       very small
+  F_{*}inv faint star involved
+  [circle] planetary
+
+
+POSITIONS OF KNOWN NEBULAE DETERMINED FROM THE CROSSLEY NEGATIVES.
+
+  +----------------------------------------------------------------------+
+  |N.G.C. |[Greek: a]|Precession|[Greek: d]|Precession|     Remarks.     |
+  |       |  1900.0  |          |  1900.0  |          |                  |
+  |----------------------------------------------------------------------|
+  |       | h  m   s |     s    |  deg.  '  '' |     ''   |                  |
+  | 185   | 0 33 27.9| +3.2866  |+47 47  8 | +19.840  |                  |
+  | 247   | 0 42 11.0|  2.9770  |-21 18 21 |  19.708  |                  |
+  | 253   | 0 42 38.6|  2.9526  |-25 50  4 |  19.701  |                  |
+  | 509   | 1 18  9.6|  3.1429  |+ 8 54 40 |  18.894  |                  |
+  | 516   | 1 18 53.2|  3.1444  |+ 9  1 46 |  18.876  |                  |
+  | 518   | 1 19  3.0|  3.1428  |+ 8 48 32 |  18.871  |                  |
+  | 522   | 1 19 30.6|  3.1486  |+ 9 28 19 |  18.857  |                  |
+  | 524   | 1 19 33.0|  3.1414  |+ 9  1  2 |  18.856  |                  |
+  | 525   | 1 19 37.9|  3.1464  |+ 9 10 54 |  18.854  |                  |
+  | 532   | 1 20  2.5|  3.1430  |+ 8 44 35 |  18.841  |                  |
+  | ...   | 1 21  7.3|  3.1493  |+ 9 23 21 |  18.810  |N. G. C. Sup. 114 |
+  | 628   | 1 31 24.8|  3.2141  |+15 16 22 |  18.473  |                  |
+  | 891   | 2 16 17.7|  3.7447  |+41 53 44 |  16.609  |                  |
+  | 906   | 2 18 59.5|  3.7502  |+41 38 10 |  16.476  |                  |
+  |1023   | 2 34  8.1|  3.7387  |+38 37 42 |  15.681  |                  |
+  |1055   | 2 36 37.5|  3.0739  |+ 0  0 48 |  15.545  |                  |
+  |1068   | 2 37 33.7|  3.0658  |- 0 26 23 |  15.493  |                  |
+  |1072   | 2 38 23.7|  3.0715  |- 0  7  8 |  15.447  |                  |
+  |1084   | 2 41  4.5|  2.9513  |- 7 59 56 |  15.300  |                  |
+  |1638   | 4 36 33.4|  3.0287  |- 2  0  6 |   7.139  |                  |
+  |1931   | 5 24 48.7|  3.9695  |+34 10  7 | + 3.067  |                  |
+  |2366   | 7 18 19.3|  6.4249  |+69 24 51 | - 6.718  |                  |
+  |2371-2 | 7 19 16.4|  3.7891  |+29 41 13 |   6.797  |                  |
+  |2403   | 7 27 11.7|  5.8367  |+65 49 13 |   7.445  |                  |
+  |2624   | 8 32 24.2|  3.4566  |+20  4 24 |  12.370  |                  |
+  |2683   | 8 46 27.6|  3.7417  |+33 47 51 |  13.317  |                  |
+  |2841   | 9 15  7.8|  4.1755  |+51 24  3 |  15.080  |                  |
+  |2903, 5| 9 26 30.4|  3.4065  |+21 56 15 |  15.716  |N. G. C. 2903 and |
+  |       |          |          |          |          |  2905            |
+  |3003   | 9 42 39.1|  3.5786  |+33 53 9  |  16.553  |                  |
+  |3021   | 9 45  1.0|  3.5735  |+34 1 14  |  16.670  |                  |
+  |3031   | 9 47 17.9|  5.0430  |+69 32 14 |  16.785  |                  |
+  |3079   | 9 55 11.4|  4.1050  |+56  9 34 |  17.147  |                  |
+  |3115   |10  0 15.1|  2.9877  |- 7 14  6 |  17.372  |                  |
+  |3156   |10  7 30.5|  3.1107  |+ 3 37 29 |  17.680  |                  |
+  |3166   |10  8 34.9|  3.1143  |+ 3 55 11 |  17.724  |                  |
+  |3169   |10  9  4.2|  3.1154  |+ 3 57 41 |  17.744  |                  |
+  |3184   |10 12 17.4|  3.6158  |+41 55 27 |  17.874  |                  |
+  |3198   |10 13 47.9|  3.6919  |+46  3  3 |  17.933  |                  |
+  |3222   |10 17  6.5|  3.2879  |+20 23 30 |  18.062  |                  |
+  |3227   |10 17 59.1|  3.2864  |+20 24 14 |  18.094  |                  |
+  |3226   |10 18  2.8|  3.2859  |+20 22 13 |  18.097  |                  |
+  | ...   |10 20 55.2|  4.5248  |+68 55 14 |  18.204  |Coddington's Neb. |
+  |       |          |          |          |          |  in _Ursa Major_.|
+  |3556   |11  5 36.8|  3.5420  |+56 13  0 |  19.485  |                  |
+  |3587   |11  9  0.1|  3.5029  |+55 33 47 |  19.553  |                  |
+  |3623   |11 13 42.8|  3.1374  |+13 38 23 |  19.639  |                  |
+  |3627   |11 15  2.2|  3.1352  |+13 32 18 |  19.662  |                  |
+  |3726   |11 27 55.4|  3.2764  |+47 34 50 |  19.851  |                  |
+  |4226   |12 11 28.2|  2.9995  |+47 34 53 |  20.024  |                  |
+  |4231   |12 11 51.1|  2.9956  |+48  0 46 |  20.022  |                  |
+  |4232   |12 11 51.2|  2.9957  |+47 59 39 |  20.022  |                  |
+  |4244   |12 12 29.4|  3.0148  |+38 24 34 |  20.017  |                  |
+  |4248   |12 12 53.1|  2.9890  |+47 57 52 |  20.016  |                  |
+  |4254   |12 13 45.0|  3.0509  |+14 58 19 |  20.011  |                  |
+  |4258   |12 14  0.8|  2.9821  |+47 51 35 |  20.010  |                  |
+  |4292   |12 16 10.3|  3.0639  |+ 5  9  1 |  19.997  |                  |
+  |4303   |12 16 48.7|  3.0637  |+ 5  1 42 |  19.993  |                  |
+  |4321   |12 17 51.0|  3.0418  |+16 22 36 |  19.986  |                  |
+  |4379   |12 20 11.2|  3.0382  |+16  9 43 |  19.970  |                  |
+  |4382   |12 20 21.3|  3.0321  |+18 44 45 |  19.968  |                  |
+  |4394   |12 20 53.0|  3.0310  |+18 46  7 |  19.964  |                  |
+  |4501   |12 26 56.6|  3.0304  |+14 58 21 |  19.909  |                  |
+  |4516   |12 28  5.1|  3.0282  |+15  7 38 |  19.898  |                  |
+  |4527   |12 29  2.2|  3.0629  |+ 3 12 19 |  19.886  |                  |
+  |4533   |12 29 15.6|  3.0638  |+ 2 52 39 |  19.884  |                  |
+  |4536   |12 29 20.6|  3.0642  |+ 2 44 22 |  19.883  |                  |
+  |4565   |12 31 23.3|  2.9812  |+26 32 20 |  19.859  |                  |
+  |4627   |12 37  7.3|  2.9316  |+33  7 22 |  19.784  |                  |
+  |4631   |12 37 14.4| +2.9315  |+33  5 19 | -19.783  |                  |
+  |----------------------------------------------------------------------|
+
+  +----------------------------------------------------------------------+
+  |N.G.C. |[Greek: a]|Precession|[Greek: d]|Precession|     Remarks.     |
+  |       |  1900.0  |          |  1900.0  |          |                  |
+  |----------------------------------------------------------------------|
+  |       | h  m   s |     s    |  deg.  '  '' |     ''   |                  |
+  |4712   |12 44 40.3| +2.9475  |+26  0 55 | -19.667  |                  |
+  |4725   |12 45 33.0|  2.9434  |+26  2 44 |  19.652  |                  |
+  |4736   |12 46 10.5|  2.8344  |+41 39 54 |  19.641  |                  |
+  |4747   |12 46 52.4|  2.9381  |+26 19  8 |  19.629  |                  |
+  |4826   |12 51 49.1|  2.9499  |+22 13 30 |  19.538  |                  |
+  |5055   |13 11 20.5|  2.6965  |+42 33 28 |  19.083  |                  |
+  |5194   |13 25 40.1|  2.5358  |+47 42 43 |  18.663  |                  |
+  |5247   |13 32 38.6|  3.2368  |-17 22 28 |  18.431  |                  |
+  |5457   |13 59 40.4|  2.1264  |+54 49 44 |  17.375  |                  |
+  |5857   |15  2 54.8|  2.7244  |+19 58 56 |  13.993  |                  |
+  |5859   |15  3  2.2|  2.7245  |+19 58  1 |  13.986  |                  |
+  |5866   |15  3 45.3|  1.6405  |+56  8 54 |  13.941  |                  |
+  |5870   |15  3 48.5|  1.6556  |+55 51 50 | -13.938  |                  |
+  |7315   |22 30 53.4|  2.7270  |+34 17  8 | +18.552  |                  |
+  |7331   |22 32 24.5|  2.7374  |+33 53 55 |  18.600  |                  |
+  |7333   |22 32 40.1|  2.7380  |+33 55 44 |  18.609  |                  |
+  |7336   |22 32 42.6|  2.7377  |+33 57 47 |  18.610  |                  |
+  |7340   |22 33  4.7|  2.7399  |+33 53 28 |  18.622  |                  |
+  |7537   |23  9 29.3|  3.0521  |+ 3 57 14 |  19.562  |                  |
+  |7541   |23  9 38.7|  3.0520  |+ 3 59 21 |  19.565  |                  |
+  |7778   |23 48 12.9|  3.0635  |+ 7 18 55 |  20.021  |                  |
+  |7779   |23 48 20.0|  3.0636  |+ 7 19 12 |  20.021  |                  |
+  |7780   |23 48 25.5|  3.0633  |+ 7 33 44 |  20.021  |                  |
+  |7781   |23 48 39.2|  3.0638  |+ 7 18 17 |  20.022  |                  |
+  |7782   |23 48 47.1|  3.0638  |+ 7 24 52 |  20.023  |                  |
+  |7814   |23 58  7.5|  3.0693  |+15 35 20 |  20.046  |                  |
+  |7817   |23 58 51.2|  3.0699  |+20 11 46 |  20.047  |                  |
+  +----------------------------------------------------------------------+
+
+
+
+
+LIST OF ILLUSTRATIONS.
+
+
+  +----------------------------------------------------------------------+
+  |No.                                                                   |
+  |      +---------------------------------------------------------------|
+  |      |N.G.C. No.                                                     |
+  |      |       +-------------------------------------------------------|
+  |      |       |Date.                                                  |
+  |      |       |                     +---------------------------------|
+  |      |       |                     |Exposure.                        |
+  |      |       |                     |      +--------------------------|
+  |      |       |                     |      |Enlargement.              |
+  |      |       |                     |      |     +--------------------|
+  |      |       |                     |      |     |_Orientation_ Top   |
+  |      |       |                     |      |     |   +----------------|
+  |      |       |                     |      |     |   |Remarks.        |
+  |----------------------------------------------------------------------|
+  |      |       |                     |h  m  |     |   |                |
+  | 1    |  224  | 1899, September 7   |3  0  |  2.0|W  |Great nebula in |
+  |      |       |                     |      |     |   |  _Andromeda_.  |
+  | 2    |  253  | 1902, December 18-20|3  0  |  2.5|S  |H V, 1.         |
+  | 3    |  598  | 1899, September 12  |3 30  |  2.1|W  |M 33.           |
+  | 4    |  628  | 1899, October 31    |4  0  |  3.4|S  |M 74.           |
+  | 5    |  650  | 1899, September 11  |3  0  |  3.4|S  |M 76.           |
+  | 6    |  891  | 1899, November 6    |4  0  |  3.4|S  |H V, 19.        |
+  | 7    | 1068  | 1899, December 3    |3  0  |  7.2|S  |M 77.           |
+  | 8    |  ..   | 1899, December 28   |4  0  |  2.1|W  |_Pleiades_.     |
+  | 9    | 1952  | 1899, December 24   |2  0  |  3.4|S  |Crab nebula.    |
+  |10    |  ..   | 1898, November 16   |0 40  |  2.2|S  |Great nebula in |
+  |      |       |                     |      |     |   |  _Orion_.      |
+  |11    |  ..   | 1899, February 9    |0  5  |  2.5|S  |Great nebula in |
+  |      |       |                     |      |     |   |  _Orion_.      |
+  |12    | 1977  | 1900, January 21    |2 50  |  2.4|S  |H V, 30.        |
+  |13    | 2024  | 1902, January 28    |3  0  |  2.4|S  |H V, 28.        |
+  |14    | 2068  | 1902, November 26   |3  0  |  2.4|S  |M 78.           |
+  |15    | 2264  | 1903, February 23   |3  0  |  2.5|S  |Nebula near 15  |
+  |      |       |                     |      |     |   |  _Monocerotis_.|
+  |16    |  ..   | 1903, February 26   |4  0  |  2.5|S  |New nebula in   |
+  |      |       |                     |      |     |   |  _Monoceros_   |
+  |      |       |                     |      |     |   |  (Roberts).    |
+  |17    | 2403  | 1900, February 27   |4  0  |  3.4|S  |H V, 44.        |
+  |18    | 2683  | 1900, February 23   |3 20  |  3.3|S  |H I, 200.       |
+  |19    | 2841  | 1901, April 17      |3  0  |  3.4|S  |H I, 205.       |
+  |20    |2903-5 | 1900, February 24   |3 30  |  3.4|S  |H I, 56, 57.    |
+  |21    | 3031  | 1900, March 21      |3 55  |  3.4|S  |M 81.           |
+  |22    | 3115  | 1901, April 9       |2 30  |  5.0|S  |H I, 163.       |
+  |23    |3198   | 1900, March 24      |4  0  |  4.3|S  |H I, 199.       |
+  |24    |3226-7 | 1901, April 10      |3  0  |  3.4|S  |H II, 28, 29.   |
+  |25_{1}|       |{1901, April 9       |0  1  | 20  |S  |H IV, 27.       |
+  |      |3242   |{                    |      |     |   |                |
+  |25_{2}|       |{1901, April 8       |0 10  | 20  |S  |H IV, 27.       |
+  |26    |3556   | 1902, May 3         |4  0  |  3.3|S  |H V, 46.        |
+  |27    |3587   | 1900, March 28      |4  0  |  3.3|S  |Owl nebula.     |
+  |28    |3623   | 1900, April 23      |3 30  |  3.8|S  |M 65.           |
+  |29    |3627   | 1900, April 23      |3 30  |  4.3|S  |M 66.           |
+  |30_{A}|3726   | 1900, March 29      |4  0  |  4.9|S  |H II, 730.      |
+  |30_{B}|3726   | 1900, March 29      |4  0  |  4.9|S  |H II, 730.      |
+  |31    |4244   | 1900, March 30      |3  0  |  3.7|S  |H V, 41.        |
+  |32    |4254   | 1902, June 7        |3 19  |  3.7|S  |M 99.           |
+  |33    |4258   | 1903, May 23        |3 53  |  3.8|S  |H V, 43.        |
+  |34    |4303   | 1900, April 27      |3  0  |  3.4|S  |M 61.           |
+  |35    |4321   | 1901, April 19      |3  0  |  4.2|S  |M 100.          |
+  |36    |4485-90| 1901, April 17      |1 45  |  4.4|S  |H I, 197-8.     |
+  |37    |4501   | 1902, June 27-28    |3  0  |  3.9|S  |M 88.           |
+  |38    |4536   | 1903, May 27        |3 30  |  3.3|S  |H V, 2.         |
+  |39    |4559   | 1901, May 9         |3  0  |  3.4|S  |H I, 92.        |
+  |40    |4565   | 1901, April 21      |3  0  |  3.3|S  |H V, 24.        |
+  |41    |4631   | 1902, June 6        |3  0  |  3.3|S  |H V, 42.        |
+  |42    |4725   | 1902, June 30-July 2|3 32  |  3.4|S  |H I, 84.        |
+  |43    |4736   | 1902, July 7        |0 30  |  3.3|S  |M 94.           |
+  |44    |4736   | 1902, July 4        |3  0  |  3.3|S  |M 94.           |
+  |45    |4826   | 1900, May 27        |2 30  |  3.8|S  |M 64.           |
+  |46    |5055   | 1902, July 5        |3 30  |  3.3|S  |M 63.           |
+  |47    |5194-5 | 1899, May 10        |4  0  |  3.3|S  |M 51.           |
+  |48    |5272   | 1900, May 22        |1 30  |  3.8|S  |M 3.            |
+  |49    |5457-8 | 1899, June 8        |4  0  |  3.2|S  |M 101.          |
+  |50    |5857-9 | 1900, May 31        |2 30  |  7.2|S  |H II, 751-2.    |
+  |51    |5866   | 1902, July 28       |3  0  |  4.9|S  |H I, 215.       |
+  |52    |5904   | 1900, May 24        |1 30  |  3.7|S  |M 5.            |
+  |53    |6205  | 1900, June 22        |2  0  |  3.8|S  | M 13.          |
+  |54    |6218  | 1899, July 11        |2  0  |  3.7|S  | M 12.          |
+  |55    |6514  | 1899, July 6         |3  0  |  4.1|S  | Trifid nebula. |
+  |56    |6523  | 1899, July 7         |4  0  |  2.0|W  | M 8.           |
+  |57    |6543  | 1899, August 8       |0  5  | 19  |S  | H IV, 37.      |
+  |58    |6618  | 1899, July 9         |4  0  |  3.1|S  | Omega nebula.  |
+  |59    |6720  | 1899, July 14        |0 10  | 13  |S  | M 57.          |
+  |60    |6853  | 1899, July 31        |3  0  |  3.8|S  | Dumb-Bell      |
+  |      |       |                     |      |     |   |  nebula.       |
+  |61    |6894  | 1899, August 9       |1  0  |  7.2|S  | H IV, 13.      |
+  |62    |6946  | 1899, August 7       |4  0  |  3.9|S  | H IV, 76.      |
+  |63    |6995  | 1899, August 29      |4  0  |  2.2|S  | Network nebula |
+  |      |       |                     |      |     |   |  in _Cygnus_.  |
+  |64    |7009  |{1899, July 28        |0 10  |}17  |S {| H IV, 1.       |
+  |      |      |{1899, July 30        |0  2  |}    |  {| H IV, 1.       |
+  |65    |7023  | 1903, August 19-20   |3  0  |  3.8|S  | H IV, 74.      |
+  |66    |7217  | 1899, August 12      |4  0  |  7.1|S  | H II, 207.     |
+  |67    |7331  | 1899, August 11      |4  0  |  3.8|S  | H I, 53.       |
+  |68    |7479  | 1899, August 9       |2  0  |  4.8|S  | H I, 55.       |
+  |      |      |                      | {10^s|}    |   |                |
+  |      |      |                      | {20^s|}    |   |                |
+  |69    |7662  | 1899, September 5    | {30^s|}17  |S  |  H, IV, 18.    |
+  |      |      |                      | { 1^m|}    |   |                |
+  |      |      |                      | { 2^m|}    |   |                |
+  |70    |7814  | 1899, September 30   |3  0  |  4.9|S  | H II, 240.     |
+  +----------------------------------------------------------------------+
+
+
+
+
+[Illustration: _Plate 1_
+
+_THE GREAT NEBULA IN ANDROMEDA_]
+
+
+[Illustration: _Plate 2_
+
+_THE SPIRAL NEBULA H.V.I. CETI_]
+
+
+[Illustration: _Plate 3_
+
+_THE SPIRAL NEBULA M.33 TRIANGULI_]
+
+
+[Illustration: _Plate 4_
+
+_THE SPIRAL NEBULA M.74 PISCIUM_]
+
+
+[Illustration: _Plate 5_
+
+_THE NEBULA M.76 PERSEI_]
+
+
+[Illustration: _Plate 6_
+
+_THE NEBULA H.V. 19 ANDROMEDAE_]
+
+
+[Illustration: _Plate 7_
+
+_THE SPIRAL NEBULA M.77 CETI_]
+
+
+[Illustration: _Plate 8_
+
+_THE PLEIADES_]
+
+
+[Illustration: _Plate 9_
+
+_THE CRAB NEBULA IN TAURUS_]
+
+
+[Illustration: _Plate 11_
+
+_CENTRAL PORTION OF THE GREAT NEBULA IN ORION_]
+
+
+[Illustration: _Plate 12_
+
+_THE NEBULA H.V. 30, ORIONIS_]
+
+
+[Illustration: _Plate 13_
+
+_THE NEBULA H.V. 28 ORIONIS_]
+
+
+[Illustration: _Plate 14_
+
+_THE NEBULA M.78 ORIONIS_]
+
+
+[Illustration: _Plate 15_
+
+_NEBULA NEAR 15 MONOCEROTIS_]
+
+
+[Illustration: _Plate 16_
+
+_NEW NEBULA IN MONOCEROS (ROBERTS)_]
+
+
+[Illustration: _Plate 17_
+
+_THE SPIRAL NEBULA H.V.44 CAMELOPARDI_]
+
+
+[Illustration: _Plate 18_
+
+_THE NEBULA H.I.200 LEONIS MINORIS_]
+
+
+[Illustration: _Plate 19_
+
+_THE SPIRAL NEBULA H.I.205 URSAE MAJORIS_]
+
+
+[Illustration: _Plate 20_
+
+_THE SPIRAL NEBULA H.I.56-57 LEONIS_]
+
+
+[Illustration: _Plate 21_
+
+_THE SPIRAL NEBULA M 81, URSAE MAJORIS_]
+
+
+[Illustration: _Plate 22_
+
+_THE NEBULA H.I.163, SEXTANTIS_]
+
+
+[Illustration: _Plate 23_
+
+_THE SPIRAL NEBULA H.I.199, URSAE MAJORIS_]
+
+
+[Illustration: _Plate 24_
+
+_THE DOUBLE NEBULA H.II 28-29, LEONIS_]
+
+
+[Illustration: _Plate 25_
+
+_THE PLANETARY NEBULA H.IV 27, HYDRAE_]
+
+
+[Illustration: _Plate 26_
+
+_THE NEBULA H.V 46, URSAE MAJORIS_]
+
+
+[Illustration: _Plate 27_
+
+_THE OWL NEBULA, M 97, URSAE MAJORIS_]
+
+
+[Illustration: _Plate 28_
+
+_THE SPIRAL NEBULA M 65, LEONIS_]
+
+
+[Illustration: _Plate 29_
+
+_THE SPIRAL NEBULA M 66, LEONIS_]
+
+
+[Illustration: _Plate 30_
+
+_THE SPIRAL NEBULA H.II, 730, URSAE MAJORIS_]
+
+
+[Illustration: _Plate 31_
+
+_THE NEBULA H.V 41, CANUM VENATICORUM_]
+
+
+[Illustration: _Plate 32_
+
+_THE SPIRAL NEBULA M 99, COMAE BERENICES_]
+
+
+[Illustration: _Plate 33_
+
+_THE SPIRAL NEBULA H.V 43, URSAE MAJORIS_]
+
+
+[Illustration: _Plate 34_
+
+_THE SPIRAL NEBULA M 61, VIRGINIS_]
+
+
+[Illustration: _Plate 35_
+
+_THE SPIRAL NEBULA M 100, COMAE BERENICES_]
+
+
+[Illustration: _Plate 36_
+
+_THE NEBULA H.I 197-198, CANUM VENATICORUM_]
+
+
+[Illustration: _Plate 37_
+
+_THE SPIRAL NEBULA M 88, COMAE BERENICES_]
+
+
+[Illustration: _Plate 38_
+
+_THE SPIRAL NEBULA H.V 2, VIRGINIS_]
+
+
+[Illustration: _Plate 39_
+
+_THE SPIRAL NEBULA H.I 92, COMAE BERENICES_]
+
+
+[Illustration: _Plate 40_
+
+_THE NEBULA H.V 24, COMAE BERENICES_]
+
+
+[Illustration: _Plate 41_
+
+_THE NEBULA H.V 42, COMAE BERENICES_]
+
+
+[Illustration: _Plate 42_
+
+_THE SPIRAL NEBULA H.I 84, COMAE BERENICES_]
+
+
+[Illustration: _Plate 43_
+
+_THE SPIRAL NEBULA M 94, CANUM VENATICORUM_]
+
+
+[Illustration: _Plate 44_
+
+_THE SPIRAL NEBULA M 94 CANUM VENATICORUM_]
+
+
+[Illustration: _Plate 45_
+
+_THE SPIRAL NEBULA M 64, COMAE BERENICES_]
+
+
+[Illustration: _Plate 46_
+
+_THE SPIRAL NEBULA M 63, CANUM VENATICORUM_]
+
+
+[Illustration: _Plate 47_
+
+_THE SPIRAL NEBULA M 51, CANUM VENATICORUM_]
+
+
+[Illustration: _Plate 48_
+
+_THE STAR CLUSTER M 3, CANUM VENATICORUM_]
+
+
+[Illustration: _Plate 49_
+
+_THE SPIRAL NEBULA M 101, URSAE MAJORIS_]
+
+
+[Illustration: _Plate 50_
+
+_THE DOUBLE NEBULA H.II 751-752, BOOTIS_]
+
+
+[Illustration: _Plate 51_
+
+_THE NEBULA H.I 215, DRACONIS_]
+
+
+[Illustration: _Plate 52_
+
+_THE STAR CLUSTER M 5, LIBRAE_]
+
+
+[Illustration: _Plate 53_
+
+_THE STAR CLUSTER M 13, HERCULIS_]
+
+
+[Illustration: _Plate 54_
+
+_THE STAR CLUSTER M 12, OPHIUCHI_]
+
+
+[Illustration: _Plate 55_
+
+_THE TRIFID NEBULA, M 20, SAGITTARII_]
+
+
+[Illustration: _Plate 56_
+
+_THE NEBULA M 8, SAGITTARII_]
+
+
+[Illustration: _Plate 57_
+
+_THE PLANETARY NEBULA H.IV 37, DRACONIS_]
+
+
+[Illustration: _Plate 58_
+
+_THE HORSE SHOE OR OMEGA NEBULA M 17, SAGITTARII_]
+
+
+[Illustration: _Plate 59_
+
+_THE RING NEBULA, M.57, IN LYRA_]
+
+
+[Illustration: _Plate 60_
+
+_THE DUMB-BELL NEBULA IN VULPECULA_]
+
+
+[Illustration: _Plate 61_
+
+_THE ANNULAR NEBULA H.IV 13, CYGNI_]
+
+
+[Illustration: _Plate 62_
+
+_THE SPIRAL NEBULA H.IV 76, CEPHEI_]
+
+
+[Illustration: _Plate 63_
+
+_THE NET-WORK NEBULA IN CYGNUS_]
+
+
+[Illustration: _Plate 64_
+
+_THE PLANETARY NEBULA H.IV 1, AQUARII_]
+
+
+[Illustration: _Plate 65_
+
+_THE NEBULA H.IV 74, CEPHEI_]
+
+
+[Illustration: _Plate 66_
+
+_THE NEBULA H.II 207, PEGASI_]
+
+
+[Illustration: _Plate 67_
+
+_THE SPIRAL NEBULA H.I 53, PEGASI_]
+
+
+[Illustration: _Plate 68_
+
+_THE SPIRAL NEBULA H.I 55, PEGASI_]
+
+
+[Illustration: _Plate 69_
+
+_THE PLANETARY NEBULA H.IV 18, ANDROMEDAE_]
+
+
+[Illustration: _Plate 70_
+
+_THE NEBULA H.II 240, PEGASI_]
+
+
+
+
+FOOTNOTES:
+
+[1] Reprinted from _The Astrophysical Journal_, =11=, 325, 1900.
+
+[2] For a more complete history of this part of the subject, see Dr.
+Holden's articles in _Pub. Ast. Soc. Pacific_, =7=, 197 _et seq._, 1895.
+
+[3] The difficulties here referred to, about which a good deal has been
+written, seem to have had their origin in the fact that it was impossible,
+at the time of the preliminary trials, to provide the observer with an
+assistant, while the Crossley reflector is practically unmanageable by a
+single person.
+
+[4] _Mon. Not. R. A. S._, =48=, 386.
+
+[5] Kindly lent by the Astronomical Society of the Pacific.
+
+[6] _Mem. R. A. S._, =46=, 173.
+
+[7] _Mon. Not. R. A. S._, =48=, 280, 1888.
+
+[8] _Mon. Not. R. A. S._, =49=, 297. The construction here described is
+not followed exactly in the Crossley apparatus. The guiding eyepiece
+slides freely when not held by a clamp. Pin-holes for preventing fogging
+are unnecessary when red light is used.
+
+[9] It so happens that the tension of the vertical thread is such that it
+begins to slacken when the temperature falls to within about 2 deg. of the dew
+point. The thread thus forms an excellent hygrometer, which is constantly
+under the eye of the observer. When the thread becomes slack, it is time
+to cover the mirrors.
+
+[10] _Mon. Not. R. A. S._, =48=, 352.
+
+[11] The following list includes all papers of interest:
+
+"Photographic Observations of Comet I, 1898 (Brooks), made with the
+Crossley Reflector of the Lick Observatory." A. J. No. 451, =19=, 151; see
+also _Ap. J._, =8=, 287.
+
+"The Small Bright Nebula near _Merope_," _Pub. A. S. P._, =10=, 245.
+
+"On Some Photographs of the Great Nebula in _Orion_, taken by means of the
+Less Refrangible Rays in its Spectrum," _Ap. J._, =9=, 133. See also _Pub.
+A. S. P._, =11=, 70; _Ap. J._, =10=, 167; _A. N._, 3601.
+
+"Small Nebulae discovered with the Crossley Reflector of the Lick
+Observatory," _Mon. Not. R. A. S._, =59=, 537.
+
+"The Ring Nebula in _Lyra_," _Ap. J._, =10=, 193.
+
+"The Annular Nebula H. IV. 13 in _Cygnus_," _Ap. J._, =10=, 266; see also
+_Pub. A. S. P._, =11=, 177.
+
+"On the Predominance of Spiral Forms among the Nebulae," _A. N._, 3601.
+
+"The Distribution of Stars in the Cluster _Messier 13_ in _Hercules_" (by
+H. K. Palmer), _Ap. J._, =10=, 246.
+
+"The Photographic Efficiency of the Crossley Reflector," _Pub. A. S. P._,
+=11=, 199; _Observatory_, =22=, 437.
+
+"New Nebulae discovered photographically with the Crossley Reflector of the
+Lick Observatory," _Mon. Not. R. A. S._, =60=, 128.
+
+"The Spiral Nebula, H. I., _55 Pegasi_," _Ap. J._, =11=, 1.
+
+"Photographic Observations of Hind's Variable Nebula in _Taurus_, made
+with the Crossley Reflector of the Lick Observatory," _Mon. Not. R. A.
+S._, =60=, 424.
+
+"Use of the Crossley Reflector for Photographic Measurements of Position,"
+_Pub. A. S. P._, =12=, 73.
+
+"Discovery and Photographic Observations of a New Asteroid 1899 FD.," _A.
+N._, 3635.
+
+"Elements of Asteroid 1899 FD." (by H. K. Palmer), _A. N._ 3635.
+
+[12] Footnote added in 1908: This concluding paragraph, retained in the
+present publication for completeness, loses point in some particulars,
+because the photogravure referred to is not reproduced here. The
+heliogravure reproduction of the Trifid nebula is No. 55.
+
+[13] Since then a photograph by Dr. Roberts has appeared in _Knowledge_,
+=23=, 35, February, 1900.
+
+
+
+
+Transcriber's Notes:
+
+Passages in italics are indicated by _italics_.
+
+Passages in bold are indicated by =bold=.
+
+Superscripted characters are indicated by ^x.
+
+Subscripted characters are indicated by _{x}.
+
+The original text utilizes a circle symbol; this is represented in this
+text version as [circle].
+
+
+
+
+
+
+End of the Project Gutenberg EBook of Photographs of Nebulae and Clusters, by
+James Edward Keeler
+
+*** END OF THIS PROJECT GUTENBERG EBOOK PHOTOGRAPHS OF NEBULAE AND CLUSTERS ***
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