(gift at 
 
 CLASS 
 
 ACC_ 
 
GIFT OF 
 BOHEMIAN CLUB 
 
 
THE AMATEUR 
 TELESCOPIST'S HANDBOOK 
 
THE AMATEUR 
 
 TELESCOPIST'S HANDBOOK 
 
 BY 
 
 FRANK M. GIBSON, PH.D., LL.B. 
 
 NEW YORK 
 
 LONGMANS, GREEN, AND CO. 
 
 15 EAST SIXTEENTH STREET 
 1894 
 
COPYRIGHT, 1893, BY 
 LONGMANS, GREEN, AND CO. 
 
 1, 173 Macdougal Street, New York 
 
r 
 
 PR^ESIDI, PROFESSORIBUS GUBERNATORIBUSQUE 
 
 COLLEGII SANCTI JOHANNIS, 
 
 ANNAPOLE, IN TERRA - MARLE, 
 
 HONORIS AB EIS DONATI 
 
 MEMOR, 
 
 HOC OPUSCULUM DEDICAVIT 
 SCRIPTOR. 
 
 701032 
 
"THE works and design of the Omnipotent Creator are inscru- 
 table to the most brilliant human intellect; yet enough is revealed, 
 both with regard to the wondrous universe and our own mental 
 capacity, to convince the reflecting mind that it is a mark of devotion 
 which we owe to our Maker to study with earnestness the beautiful 
 and harmonious works around us, however their immensity may at first 
 bewilder us. He who zealously applies himself will verify the sacred 
 promise, 'Those who seek shall find.' In worldly pursuits a long 
 novitiate is devoted to acquire the imperfect concoctions of man; how 
 much more is due to catch a glimpse of the imperishable laws of the 
 CREATOR !" ADMIRAL WILLIAM HENRY SMYTH. 
 
PREFACE. 
 
 THIS little book is offered to amateurs in astronomy in 
 the belief that it fills a want as yet unsupplied. 
 
 For the possessors of equatorially mounted telescopes 
 of an aperture exceeding three or four inches, efficient 
 guides are already in existence. Smyth's Cycle of Celes- 
 tial Objects and Webb's Celestial Objects for Common Tele- 
 scopes fulfil almost every requirement of such observers. 
 But for the far larger number of students of astronomy 
 whose instrumental equipment does not go beyond a two 
 or three-inch altazimuth, these admirable works are to a 
 considerable extent unsuited. The worker with an equa- 
 torial can quickly and easily direct his telescope to any 
 object described in those mines of celestial wealth ; but 
 for his humbler brother there is no resource but to labo- 
 riously locate the given star or nebula on a map, note its 
 position with reference to other objects, and then search 
 for it with the altazimuth. Moreover, these immense col- 
 lections of celestial objects contain a very large number 
 of bodies which are hopelessly beyond the reach of a 
 small telescope ; and the novice knows not which among 
 them may be expected to reveal themselves by the assist- 
 ance of his little instrument, and is at a loss where to 
 begin his scrutiny of the heavens. If all this work could 
 be done for him ; if a selection could be made of such 
 objects as are within the powers of, at most, a three-inch 
 telescope, and the location of each of them be concisely 
 and yet fully described with reference to objects visible 
 
X PREFACE. 
 
 to the unaided eye, a vast quantity of uncertainty, difficulty, 
 and labor would be cleared out of the student's path. 
 And if, in addition to this, a method could be provided 
 by which the use of a map by lantern-light could be 
 entirely dispensed with, and the position of every star 
 used in locating others could be ascertained almost at a 
 glance, it is very evident that the drawbacks and difficul- 
 ties encountered by the amateur observer would be greatly 
 modified, if not in the main removed. 
 
 Precisely this is what has been done in the catalogue of 
 between four and five hundred celestial objects contained 
 in this book ; and upon this fact is based the author's 
 belief that the Handbook will fill a want in this field. 
 
 That portion of the book which treats of the principles, 
 construction, care, and use of the Telescope is drawn from 
 many sources, and contains, it is believed, more practical 
 information upon the subject than any other one volume 
 treating of this instrument. A certain knowledge of as- 
 tronomy on the reader's part is assumed ; but not more 
 than can be obtained from any primer of the science. 
 
 The illustrations are limited to such as are necessary to 
 convey essential information, and it will be noticed that 
 no attempt has been made to give any of the diagrams of 
 double stars which are so common in books upon this 
 subject prepared for amateurs. Even if a pair of dead- 
 white disks on a black ground could really represent the 
 glittering and twinkling stars, they would not serve the 
 purpose which is usually assigned for their existence, 
 namely, to give the student an idea where to look for the 
 companion of the star represented. For the apparent 
 relative positions of the star and its comes change with 
 the successive positions of the object in its course across 
 the sky ; and as these diagrams usually represent the rel- 
 
PREFACE. XI 
 
 ative positions of the components when the star is on 
 the meridian, they would be useless for the purpose 
 assigned when it was at any distance from that line. 
 
 No attempt has been made to treat of the Reflecting 
 Telescope. This instrument is but little known in Amer- 
 ica, although it must some day come into favor in this 
 country, as it has always been in England, especially 
 since the introduction of the silvered-glass speculum, 
 since its cheapness, in comparison with refractors of cor- 
 responding aperture, makes it, in one sense, preeminently 
 the amateur's telescope. Should a future edition of this 
 Handbook ever be called for, some space may be devoted 
 to the Reflector. 
 
 In conclusion, the author trusts that this little work 
 may prove a helpful and pleasant companion to amateur 
 astronomers in the study of the sublimest of the physical 
 sciences and the use of the noblest of optical instruments. 
 
 WASHINGTON, D. C., 
 November^ 1893. 
 
CONTENTS. 
 
 PAGE 
 
 PREFACE ix 
 
 CHAPTER I. THE TELESCOPE: ITS PRINCIPLES AND 
 
 POWERS i 
 
 " II. TESTING THE OBJECT GLASS. EYEPIECES. 
 
 TUBES 16 
 
 " III. THE STAND 28 
 
 " IV. ACCESSORIES OF THE TELESCOPE 39 
 
 " V. THE CARE OF THE TELESCOPE. 42 
 
 VI. THE USE OF THE TELESCOPE 45 
 
 VII. OBSERVATION. STARS, NEBULAE, THE SUN 
 
 AND MOON 52 
 
 14 VIII. OBSERVATION, CONTINUED. THE PLANETS. 66 
 ** IX. PRICES OF TELESCOPES AND THEIR ACCES- 
 SORIES 74 
 
 CELESTIAL OBJECTS: 
 
 ALIGNMENT STARS 83 
 
 A DESCRIPTIVE CATALOGUE OF FOUR HUNDRED AND 
 
 SIXTY-EIGHT CELESTIAL OBJECTS 90 
 
THE 
 AMATEUR TELESCOPIST'S HANDBOOK, 
 
 CHAPTER I. 
 
 THE TELESCOPE I ITS PRINCIPLES AND POWERS. 
 
 AN opportunity to examine celestial objects by means 
 of a telescope is one which is so eagerly embraced by 
 almost all classes of people as to indicate that telescopic 
 astronomy possesses a charm which should lead to its ex- 
 tensive cultivation ; but the efforts of writers on this sub- 
 ject have been comparatively unsuccessful in persuading 
 students of natural science to believe that a small tele- 
 scope is capable of gratifying, in any real sense, the taste 
 for these fascinating pursuits. The popular idea of the 
 telescope is of a huge and costly instrument, the posses- 
 sion of which must necessarily be limited to educational 
 institutions, public observatories, and wealthy amateurs ; 
 and the fact that most of the work of modern astronomy 
 is done by such instruments serves to confirm this impres- 
 sion. The monster reflectors of Herschel, Rosse, and 
 Lassell ; the colossal refractors of Mount Hamilton, Chi- 
 cago, and Washington, are the instruments suggested to 
 the average mind by the word telescope; and a diminutive 
 tube of two or three inches aperture is neglected and dis- 
 dained as incapable of doing aught but tantalize the 
 student who is unable to procure anything better. And 
 I i 
 
2 THE' AMATEUR. .T^LESCOPIST's HANDBOOK. 
 
 thfcn, When the 'would-be possessor of a telescope comes to 
 examine price lists, he is apt to stand aghast at the man- 
 ner in which the cost of object glasses advances with every 
 half inch of aperture ; and it is only too probable that he 
 will surrender the idea of surveying the heavens through 
 a glass of his own. 
 
 The catalogues of celestial objects given in this book 
 should be, and the author hopes will be, an effectual 
 refutation of the fancy that nothing can be done with a 
 small telescope. There is scarcely an object contained in 
 them which is not fairly within the compass of a good three- 
 inch achromatic. The exceptions to and modifications 
 of this statement will appear in their proper places ; but 
 the reader is assured of the correctness of the general rule. 
 
 There is a tendency in certain quarters to encourage 
 the amateur astronomer provided he wishes to do work 
 of value to the science, but to speak with contempt of 
 mere "star-gazing." This tendency is exhibited in more 
 than one book prepared for the use of astronomical ama- 
 teurs, and has served to discourage more than one student 
 who was unable to provide himself with the means for 
 doing serious astronomical work, or to acquire the neces- 
 sary skill in using them. 
 
 Now, it might as well be stated at once that there is 
 scarcely a possibility in these days that an amateur with 
 a small altazimuth telescope can accomplish any work of 
 scientific value. There are, indeed, certain fields open to 
 him e.g., he may observe occultations by the aid of a 
 good chronometer, and with skill and care may thus make 
 some contribution toward the improvement of the lunar 
 theory ; * but even assuming that he possesses a chronom- 
 
 * Noble. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 3 
 
 eter and the means for accurately regulating it, work of 
 this kind is already being done by accomplished astrono- 
 mers provided with the most perfect instruments which 
 modern skill can construct. So of every other branch of 
 telescopic astronomy. In earlier days, when astronomical 
 instruments were less perfect, professional astronomers 
 less numerous, and the magnificent observatories of 
 modern times as yet unknown, the amateur with his little 
 telescope might be a distinguished and valued co-laborer 
 with the professional with his not very much larger instru- 
 ment. That day is past ; and it is most likely that the 
 small telescope has done all of which it is capable in 
 the way of original scientific work. 
 
 But surely what remains within the power of this humble 
 little member of the mighty family of telescopes is not to 
 be despised. To merely look with delight and wonder 
 upon the twin glitterings of the double stars, the gorgeous 
 splendor of the clusters, the pale glow of the nebulae ; 
 to scan the wild scenery of the moon ; to watch the huge 
 spots drifting across the sun ; to follow the satellites of 
 Jupiter as they circle about the giant planet ; to marvel at 
 Saturn with his "wondrous rings " ; to wait and watch for 
 the startling phenomena of occultations and eclipses ; and 
 through all this to see the working of the majestic and 
 glorious laws of the universe this is not to be set aside 
 as worthless. On the contrary, the mere " star-gazer " 
 will find a never-failing pleasure in the contemplation of 
 these stupendous objects ; and even though he may ac- 
 complish nothing for science, he will enjoy the most re- 
 fined, elegant, and fascinating of all scientific recreations. 
 
 The history of the refracting telescope divides itself 
 into three periods : that of the Galilean telescope ; that 
 
4 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 of the Astronomical telescope, strictly so called ; and that 
 of the Achromatic. While it is not within my purpose to 
 give an elaborate account of the optical principles in- 
 volved in these instruments, a brief explanation of them 
 must necessarily be introduced as highly important to the 
 telescopist. 
 
 The telescope, as invented (in all probability) by Jan- 
 sen and Lippersheim, two spectacle-makers of Middle- 
 burg, Holland, and improved by Galileo, consists of a 
 double convex lens placed at one end of a tube shorter 
 than the focal length of the glass, at the other end of 
 which is fixed a double concave lens. The rays of light 
 from any object passing through the convex lens are in- 
 
 FIG. i. 
 
 tercepted by the concave lens before the image can be 
 formed, and converted into parallel rays which enter the 
 eye of the observer applied to the latter lens. 
 
 This instrument, which in the hands of Galileo opened 
 the magnificent career of modern practical astronomy, is 
 now, by the irony of fate, known as the non-astronomical 
 telescope. It still serves a useful purpose in the opera- 
 glass ; but it was soon cashiered from the service of 
 astronomy on account of several serious and radical 
 defects. The first of these defects is that the full illumi- 
 nating power of the telescope is not made available. A 
 comparatively small number of the rays received by the 
 convex object glass are transmitted through the concave 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 5 
 
 eye-lens ; and if we use an eye-lens of shorter focus, and 
 nearer the object glass, it intercepts more of the rays, to 
 be sure, but there is no point of the eye-lens at which the 
 eye would receive pencils of light emanating from any 
 considerable portion of the object. Mr. Proctor * com- 
 pares the difference to that between looking through the 
 small end of a cone-shaped roll of paper, and looking 
 through the large end. In the first case the eye sees at 
 once all that is to be seen through the roll (supposed 
 fixed in position), and in the latter the eye may be moved 
 about so as to command the same range of view, but at 
 any instant sees over a much smaller range. 
 
 The fact that in a Galilean telescope the size of the field 
 of view is dependent upon the size of the object glass is a 
 defect, and so is the fact that any scratches, marks, or 
 partial coverings placed upon the object glass are visible 
 on looking through the telescope ; but the great defect of 
 this instrument lies in the fact that in the Galilean tele- 
 scope no real image is formed, owing to the interception 
 of the collected rays by the eye-lens before they come to 
 a focus at all. Since, then, no actual image exists, it is 
 impossible to apply any measurements to it a well-nigh 
 fatal fault from an astronomical standpoint. 
 
 FIG. 2. 
 
 The astronomical telescope, in its primitive form, consists 
 *of a double convex lens which forms an inverted image of 
 
 * Half-hours with the Telescope, p. 8. 
 
6 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 the object under examination, and a smaller double con- 
 vex lens which magnifies the image. 
 
 The rays of light falling through the object glass are re- 
 fracted to a focus in the tube, and the image thus formed 
 is magnified by the small lens at the eye-end. By this 
 arrangement of lenses the characteristic defects of the 
 Galilean telescope are avoided. The size of the field of 
 view is not dependent upon the size of the object glass. 
 Scratches or marks on the object glass are not visible in 
 the telescope, but only cause a certain loss of light, so 
 that a portion of the object glass may be covered over, 
 either at the centre or at the edges, for certain purposes, 
 without the covering object being visible, and the whole 
 of the light transmitted by the object glass becomes 
 available. Moreover, the image, being real and not 
 merely virtual, may be readily subjected to measurement, 
 either angular or linear ; a circumstance which alone 
 would make this instrument preeminently the astronomi- 
 cal telescope. 
 
 But this primitive telescope has two most serious de- 
 fects of its own which, if not removed or greatly modi- 
 fied, would have caused it to remain forever a clumsy and 
 imperfect contrivance. These are known as chromatic 
 aberration and spherical aberration* The first of these is 
 due to the unequal refrangibility of the different colors of 
 the spectrum. The image of an object thus does not lie 
 in a flat field perpendicular to the optical axis of the tel- 
 escope (i.e., a line drawn from the centre of the objective 
 to that of the eye-lens), but is in reality divided into a 
 
 * I omit all reference to the curvature of the image, as this defect 
 is of no importance, in practice, and the above discussion is merely 
 elementary. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 7 
 
 number of images of different colors lying one behind the 
 other in the optical axis. Accordingly, when the eye- 
 lens is set so as to magnify one of these images, a colored 
 fringe due to the other images, enlarged by being out of 
 focus, surrounds the image under examination. The 
 other defect, that of spherical aberration, is due to the 
 fact that the rays transmitted through the outer portions 
 of a double convex lens are brought to a focus nearer the 
 lens than those transmitted through the centre. 
 
 The correction of these faults was for more than a hun- 
 dred years the great desideratum in practical astronomy. 
 An effort was made to remedy them, and with some suc- 
 cess, by grinding lenses of enormous focal length, which 
 were elevated upon a pole and provided with mechanical 
 appliances by which the observer could direct them to 
 different parts of the heavens, and examine the images 
 formed by them with an eye lens. One of these, now in 
 the possession of the Royal Astronomical Society, was 
 made by Huygens, and has a focal length of 123 feet; 
 another was made for Louis XIV. which had a focal 
 length of 136 feet ; and Auzout had one of 600 feet ; 
 which preposterous machine he was unable to use for lack 
 of a place on which to put it. 
 
 Sir Isaac Newton despaired of ever remedying these 
 evils in the refracting telescope, and devoted his labors in 
 this field to the construction of reflectors. But the dis- 
 covery that the dispersive powers of different kinds of 
 glass were not proportional to their refractive powers set 
 opticians to work. This principle may be illustrated as 
 follows : If a ray of sunlight be permitted to pass through 
 a glass prism, it will be separated into a spectrum of a 
 length proportional to the dispersive power of the glass, 
 and it will be turned out of a straight course at an angle 
 
8 
 
 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 proportional to its refractive power. If we now substi- 
 tute for this prism another one of the same shape but of a 
 different kind of glass, the spectrum may be of the same 
 length but be thrown to a greater or less angular distance 
 than by the first prism. Working upon this principle, 
 John Dollond, of London, immortalized his name and 
 founded modern telescopy by inventing the achromatic 
 object glass in 1758. This consists of a double convex 
 lens t of crown glass combined, as in Fig. 3, 
 with a plano-convex or concavo-convex lens 
 of flint glass. 
 
 The proportion of the refractive and dis- 
 persive powers of these two kinds of glass 
 is such that the flint glass neutralizes the 
 dispersion caused by the crown glass in re- 
 fracting the rays to a focus, leaving the 
 latter free to form its image without color. 
 The defect is not absolutely cured, but 
 becomes of little moment except in examin- 
 ing an object of extraordinary brightness 
 on a dark background e.g., Venus against a dark sky. 
 The spherical aberration is also corrected by the figure 
 given to the compound lens. 
 
 The tests as to the correction of chromatic and spheri- 
 cal aberration will be duly given when we come to con- 
 sider the examination and trial of object glasses. 
 
 As the achromatic combination has superseded the 
 simple double-convex object glass, so a combination of 
 lenses has taken the place of the single eye-lens. The 
 image formed by the most perfect achromatic objective 
 would appear indistinct, distorted and colored, if viewed 
 through a common double-convex lens. The first combi- 
 nation lens, or eyepiece, for magnifying the image was 
 
 FIG. 3. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 invented by Huygens in the seventeenth century, and 
 bears his illustrious name. It consists of two plano- 
 convex lenses, mounted as in Fig. 4, with the convex 
 sides of both turned toward the image. The distance 
 between the lenses is equal 
 to one-half the sum of their 
 focal lengths, which pro- 
 duces an achromatic combi- 
 nation. This invaluable 
 instrument is still in con- 
 stant use, except in cases 
 where micrometrical meas- 
 urements are to be made. It is known as the negative 
 eyepiece, as distinguished from the one presently to be 
 described, because the image is formed between the lenses 
 composing it. This position of the image renders it im- 
 possible to use the Huygenian eyepiece in cases where 
 it is required that transit wires or a micrometer shall be 
 used in the common focus of the objective and the eye- 
 piece. In such a case the 
 yp positive eyepiece, invented by 
 Ramsden in the eighteenth 
 ^ century, is used. This is 
 represented in Fig. 5. The 
 v lenses have their convex 
 ^ sides turned toward each 
 other, and the image is 
 formed just beyond the lens 
 
 FIG. 5. 
 
 #, which is known in all eyepieces as the field glass, while 
 b is known as the eye glass. The common focus of the 
 object glass and the eyepiece can thus receive the wires 
 of a micrometer or transit system. 
 
 An Huygenian, or negative, eyepiece is equivalent to 
 
10 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 a single lens of a focal length equal to twice the product 
 of the focal lengths of the component lenses divided by 
 their sum. A positive eyepiece is equivalent to a single 
 lens of a focal length equal to the product of the focal 
 lengths of the component lenses divided by their sum, 
 minus the distance between them. In the achromatic 
 refractor, the magnifying power of the instrument with a 
 given eyepiece is expressed by the ratio of their focal 
 lengths. In other words, the power of a given eyepiece 
 is ascertained by dividing the focal length of the object 
 glass by the focal length of the eyepiece. 
 
 It is highly important that the observer know, with as 
 great accuracy as possible, the powers of each of the eye- 
 pieces of his telescope. This may be accomplished in 
 several ways. The focus of a single lens equivalent to 
 the compound one in question may be calculated by one 
 of the foregoing rules, and the focal length of the object 
 glass be divided by that of the equivalent single lens, the 
 quotient giving the magnifying power of that eyepiece 
 with that object glass. It is not very easy, however, to 
 determine the focal length of small lenses. A better 
 method is as follows : Focus the telescope accurately on 
 a distant object, and then direct the tube toward the sky. 
 On looking at the eye-lens of the eyepiece it will be seen 
 that the image of the object glass is projected thereupon 
 as a small luminous disk. Let the diameter of this disk 
 be accurately measured ; and then divide the diameter of 
 the object glass by that of the luminous circle, and the 
 quotient will give the magnifying power. 
 
 The measurement of this tiny circle is by no means 
 easy, especially with eyepieces of high power. It may 
 be accurately effected with a Ramsden dynamometer or 
 dynameter, or the simple and precise little Berthon dyna- 
 
THE AMATEUR TELESCOPJST's HANDBOOK. II 
 
 mometer made by Home, Thornthwaite & Wood, of Lon- 
 don, and sold for ten shillings. The measurement may be 
 made with tolerable accuracy by looking at the disk on 
 the eye lens with a small magnifying glass, taking its diam- 
 eter by means of a pair of compasses, and measuring the 
 distance between the points on a fine and accurate scale. 
 
 Modern eyepieces, however, are usually marked with 
 their equivalent focal length, and the power of each with 
 a given object glass is easily ascertained. 
 
 A most important question is as to the power which 
 may be used upon any object glass. The common rule 
 is that the very highest power which a good telescope 
 will bear under the most favorable atmospheric condi- 
 tions is one hundred for every inch of aperture. This is 
 doubtless correct ; but both of the conditions mentioned 
 in connection with it must be present. The range of 
 powers for practical work under ordinary circumstances 
 may be much better deduced from the following table, 
 from Chambers's Astronomy, p. 724 : 
 
 APERTURES OF 
 
 6 in. 
 
 35 
 85 
 160 
 250 
 360 
 500 
 
 Every telescope, however, should have one eyepiece 
 of the highest power that the object glass will bear, for 
 the examination of close double stars, etc., under favor- 
 able circumstances. 
 
 As regards the limit of vision of achromatic telescopes, 
 
 2 in. 
 
 3 in. 
 
 4 in. 
 
 5 in. 
 
 15 
 
 20 
 
 25 
 
 30 
 
 45 
 
 55 
 
 65 
 
 85 
 
 100 
 
 no 
 
 140 
 
 170 
 
 
 200 
 
 300 
 
 280 
 
 
 
 
 420 
 
12 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 Mr. Chambers gives the following rule, based on Arge- 
 lander's scale of magnitudes : 
 
 Multiply the logarithm of aperture in inches by 5, and 
 add 9.2 to the result. This will give the magnitude of the 
 smallest star visible with that aperture. 
 
 For instance, to find the magnitude, according to 
 Argelander's scale, of the smallest star visible in a tele- 
 scope of three inches aperture : 
 
 Log. 3, . . 0.477121 
 5 
 
 2.385605 
 Add, ... 9.2 
 
 Mag., . . 11.58 
 
 By this rule an aperture of two inches may be expected 
 to show a star of magnitude 10.7 ; one of four inches, 12.2 ; 
 one of five inches, 12.6 ; and one of six inches, 13.09, 
 according to Argelander's scale. The rule is based on the 
 assumption that a star of magnitude 9.2 is the smallest 
 which can be seen by the average observer with a one- 
 inch telescope. 
 
 Chambers gives a modification of this plan by Mr. N. 
 Pogson, of Madras, which is more accurate for the indi- 
 vidual observer and a given telescope than the above. 
 Determine by trial the smallest star, according to Arge- 
 lander's or Radcliffe's scale, which you can see with an 
 aperture of one inch. Then the limit of vision with any 
 other aperture will be : One-inch limit + 5 x log. aperture. 
 Mr. Pogson observes that the limit of vision in different 
 observers using one inch of aperture will differ less than 
 people imagine, averaging about 9^-. 
 
 It must be distinctly understood that the above rules only 
 refer to isolated stars, or those in a field containing only 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 13 
 
 stars not greatly exceeding the test-star in magnitude. 
 The magnitude of the companion of Rigel (ft Orionis), 
 for instance, is 9, and so it should be visible in a one-inch 
 telescope ; but the glare of the primary star will com- 
 pletely overwhelm the feeble light collected from the 
 companion by the object glass, and the little star will be 
 absolutely invisible. This fact must be carefully borne 
 in mind in trying double stars. 
 
 Argelander's scale of magnitudes has been referred to 
 in connection with the foregoing rules concerning the 
 limit of vision. In the star-lists given in this book, 
 Smyth's scale is used. Struve's scale is perhaps the 
 most generally accepted. The following table will show 
 at a glance the corresponding magnitudes in each of these 
 scales (G. Knott) : 
 
 TABLE OF COMPARATIVE MAGNITUDES. 
 Smyth. 
 6 
 
 6-5 
 
 7 
 
 7.5 
 8 
 
 8-5 
 
 9 
 
 9-5 
 10 
 ii 
 
 12 
 13 
 
 14 
 15 
 
 16 
 
 W. Struve. 
 
 Argelander. 
 
 5-7 
 
 5-9 
 
 6.3 
 
 6.4 
 
 6.5 
 
 6.8 
 
 6.9 
 
 7-5 
 
 7-4 
 
 8 
 
 7-9 
 
 8.6 
 
 8-3 
 
 9 
 
 8.9 
 
 9-4 
 
 9-3 
 
 9-4 
 
 10 
 
 10 
 
 10.4 
 
 10.6 
 
 10.7 
 
 II. 2 
 
 10.9 
 
 n.8 
 
 10.9 
 
 12.4 
 
 10.9 
 
 13 
 
14 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 The magnifying of celestial objects is by no means the 
 sole purpose of the telescope ; the collection of light from 
 them is an equally important function of the instrument, 
 and, in the case of the nebulae and clusters, the more im- 
 portant function. When an object is looked at with the 
 naked eye, the retina receives only so many rays as can 
 fall upon the pupil of the eye ; but by the use of the tele- 
 scope as many rays can be brought to the retina as fall 
 upon the entire object glass. " The pupil of the human 
 eye in its normal state has a diameter of about one-fifth of 
 an inch, and by the use of the telescope it is virtually in- 
 creased in surface in the ratio of the square of the diam- 
 eter of the objective to the square of one-fifth of an inch." * 
 Thus, to ascertain the light-collecting power of an objec- 
 tive, we divide the square of the diameter of the object 
 glass by the square of ^ ; or, what is the same thing, we 
 multiply the square of the diameter by 25 ; and the 
 quotient or product, as the case may be, will give the 
 light-collecting power of the object glass as compared 
 with that of the naked eye. 
 
 By the defining power of an objective is meant 
 its capacity for separating closely adjacent points of 
 visible matter. By its illuminating power is meant its 
 capacity for exhibiting very faintly lighted objects. 
 The defining and illuminating power of a given object 
 glass of any given aperture depends upon its focal 
 length. Should the focal length be very short, its 
 definition will be inferior but its illumination good, a 
 fact which is utilized in the comet-seeker. Should the 
 focal length, on the contrary, be excessive, the defini- 
 tion will be good, but the illumination poor. Moreover, 
 
 * Newcomb and Holden, Astronomy, p. 56. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 15 
 
 the greater the focal length, the smaller is the field 
 of view, and vice versa. A focal length which furnishes 
 for any given glass the maximum of both defining and 
 illuminating power is fourteen or fifteen inches for every 
 inch of aperture. 
 
CHAPTER II. 
 
 TESTING THE OBJECT GLASS. EYEPIECES. TUBES. 
 
 THE figuring of a telescopic objective is one of the 
 most difficult and delicate operations in the arts, espe- 
 cially when its diameter exceeds five or six inches. * This 
 being the case, it is to be expected that the making of 
 the highest grade of object glasses should remain, as it 
 does, in the hands of a few artists of the highest intelli- 
 gence and skill. The manufacture of perfectly homo- 
 geneous glass for this purpose is also a difficult operation. 
 The result of these facts is that object glasses of the first 
 class must necessarily be expensive instruments. An 
 estimate (although so rough as to be of little use) of the 
 cost of a high-grade objective may be formed by a rule 
 given by Professor Newcomb : multiply the cube of the 
 aperture in inches by $T and also by $1,75 ; the products 
 will give the minimum and maximum respectively of the 
 probable price. A first-class three-inch glass, according 
 to this rule, would cost from $27 to $47.25 ; a four-inch 
 from $64 to $112, and so on. I will give, however, in 
 another place, the actual prices of object glasses as sup- 
 plied by some of the best opticians of England and the 
 United States. 
 
 In testing an objective it should be first carefully ex- 
 amined in its cell. It should appear brightly polished 
 
 * On this subject see a most interesting article by Professor New- 
 comb, " The Story of a Telescope," in Scribner's Monthly for 1873, 
 vol. vii. p. 44. 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 17 
 
 and free from scratches, and preferably without bubbles or 
 sand-holes. These things, it is truly said, only cause the 
 loss of a little light, and are not incompatible with satis- 
 factory definition ; but the possessor of a small telescope 
 can ill afford to lose any light. Still, these faults are not 
 sufficient by themselves to warrant the rejection of an 
 object glass. But stria, or waves, and unequal density of 
 different parts of the glass are most serious defects. 
 
 The telescope being fully mounted and ready for use, 
 the object glass should be given the following tests : 
 
 1. As to whether the chromatic aberration has been 
 corrected. 
 
 Point the telescope toward Jupiter or the moon, 
 using in the latter case the lowest power, and focus 
 carefully. Now, if on pushing in the eyepiece a purple 
 ring appears around the edges of the disk, and on draw- 
 ing it out, a green one, then the chromatic aberration has 
 been corrected, since these are the central colors of the 
 secondary spectrum, appearing where they should. 
 
 2. As to whether the spherical aberration has been 
 corrected. 
 
 Point the telescope toward a star of moderate brilliancy, 
 say of the third magnitude, and focus carefully. Cover 
 the object glass with a piece of cardboard in which has 
 been cut a circular aperture of a diameter equal to one-half 
 that of the object glass, in such a manner that the glass 
 and the opening in the cardboard shall be concentric. If 
 on now looking through the telescope we find the star 
 still in focus, the spherical aberration has been duly cor- 
 rected. If, however, the eyepiece has to be pushed fur- 
 ther in to obtain a true focus, then the spherical aberra- 
 tion has been over-corrected ; while if it has to be drawn 
 further out, this aberration has been under-corrected. 
 
l8 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 The following valuable remarks are from the Rev. T. W. 
 Webb : * 
 
 " The image should be neat and well defined with the 
 highest power, and should come in and out of focus 
 sharply ; that is, become indistinct by a very slight motion 
 on either side of it. A proper test-object must be chosen ; 
 the moon is too easy ; Venus too severe, except for first- 
 rate glasses ; large stars have too much glare ; Jupiter or 
 Saturn are far better ; a close double star is best of all 
 for an experienced eye ; but for general purposes a 
 moderate-sized star will suffice ; its image, in focus, with 
 the highest power, should be a very small disk, almost a 
 point, accurately round, without * wings ' or rays or misti- 
 ness or false images, or appendages, except one or two 
 narrow rings of light, regularly circular, and concentric 
 with the image ; and in a regularly dark field ; a slight 
 displacement of the focus either way should enlarge the 
 disk into a luminous circle. If this circle is irregular in 
 outline, or much brighter or fainter toward the centre, 
 or much better defined on one side of the focus than 
 the other, the telescope may be serviceable, but is not of 
 high excellence. The chances are many, however, against 
 any given night being fine enough for such a purpose, 
 and a fair judgment may be made by day from the figures 
 on a watch-face, or a minute white circle on a black 
 ground, or the image of the sun on a thermometer bulb 
 placed as far off as possible. An achromatic, notwith- 
 standing the derivation of its name, will show color 
 under high powers where there is much contrast of light 
 and darkness. This ' outstanding ' or uncorrected color 
 results from the want of a perfect balance between the 
 optical properties of the two kinds of glass of which the 
 
 * Celestial Objects for Common Telescopes, p. 3. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 19 
 
 object glass is constructed ; it cannot be entirely remedied, 
 but it ought not to be obtrusive. In the best instruments 
 it forms a fringe of violet or blue round luminous objects 
 in focus under high powers, especially Venus in a dark 
 sky. A red or yellow border would be bad ; but before 
 condemning an instrument from such a cause, several eye- 
 pieces should be tried, as the fault might be there, and 
 be easily and cheaply remedied." 
 
 The " wings " spoken of in the above extract may be 
 due to several causes. They may arise from the object- 
 glass lenses having been screwed too tightly together, and 
 the fault may be corrected by very slightly loosening the 
 screw-cell in which they are placed. This cause, how- 
 ever, is an uncommon one. A much more usual cause 
 lies in the objective's not being in every part of uniform 
 refractive power a very bad and virtually incurable 
 defect. The defective portion may indeed be covered up 
 with an opaque screen, and thus, perhaps, fair definition 
 be secured at the expense of light ; but the better course 
 is to reject peremptorily any glass which has not in every 
 part the same refractive power. 
 
 These " wings " may also be due to the fact that the 
 object glass is not set at right angles with the optical 
 axis of the telescope ; a fault which would be quite 
 unpardonable in the work of an optician, and which 
 could easily be avoided by proper care in that of an 
 amateur. They may also be caused by a slight inclina- 
 tion of the eyepiece. This may be detected by covering 
 each of the glasses of the eyepiece with a circular card- 
 board screen pierced in the centre with a small aperture, 
 and covering the object glass with a similar pierced 
 screen. If the eyepiece is correctly centred, it will be 
 possible to see through the three openings at once. 
 
20 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 If the tube of the telescope is not somewhat greater 
 in diameter than the object glass, a particular form of 
 " wing " may be seen extending upward from a star like 
 the tail of a little comet, when the instrument is used in 
 the open air. This is most apt to be the case when the 
 tube is of wood, and the amateur who makes his own tele- 
 scope needs to be warned of the danger. The cause of 
 this annoying defect, which once nearly caused the rejec- 
 tion by Alvan Clark of one of his own earlier object- 
 glasses as worthless,* is that a wooden tube under the 
 cold sky radiates heat from its upper surface and at the 
 same time receives warmth from the earth under it. The 
 result is that a thin layer of warm air lies at the bottom of 
 the tube, and an equally thin layer of colder air exists at 
 the upper surface. This causes a slight upward refrac- 
 tion of the rays which pass through the outer edges of the 
 object glass, and thus produces the comet-like tail. The 
 remedy or preventive is to make the tube of sufficient 
 diameter to bring the layers of warm and cool air out of 
 the path of the rays, or to cover the tube with tinfoil, 
 which, by its inferior radiating power, will prevent the 
 trouble in question. 
 
 According to Dawes f (one of the highest of authorities 
 on the telescope), the severest test of figure for an achro- 
 matic objective is the similarity of the image of a bright 
 star, viewed with the focus too long, to the same image 
 viewed when the focus is to an equal linear extent too 
 short ; the amount of the dissimilarity being a measure 
 of the imperfection of the instrument. 
 
 The examination of stars out of focus is an important 
 
 * See Professor Newcomb's article, before referred to. 
 f Chambers, p. 617. 
 
THE AMATEUR TELESCOPISTS HANDBOOK. 
 
 21 
 
 aid in the testing of an object glass and of its mounting. 
 I append a series of figures (from Professor Newcomb) 
 giving the appearance of spectral images of stars in dif- 
 ferent telescopes, with the focus imperfect through the 
 pushing in of the eyepiece, and of the same images with 
 the focus imperfect through the drawing out of the 
 same. 
 
 There is, to a practised eye, no better test of the charac- 
 ter of an object glass than the image formed by it of a 
 star of the third or fourth magnitude. A bright little disk 
 surrounded by from one to three delicate thread-like con- 
 centric rings (called, technically, diffraction rings) proves 
 pretty conclusively the general excellence of the object 
 
 II 
 
 ffl 
 
 IV V 
 
 FIG. 6, 
 
 I. Images as they should be. 
 II. Spherical aberation shown by the light and dark centres. 
 
 III. Objective not spherical but elliptical. 
 
 IV. Glass not uniform a very bad and incurable case. 
 V. One side of objective nearer than other. Adjust it. 
 
22 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 glass. I give below two figures by Captain Noble, the 
 first showing what a star-image ought to be, and the sec- 
 ond showing, with an almost comic truthfulness, what it 
 sometimes is, but most emphatically ought not to be.* 
 The sharpness of this image should be, in a good tele- 
 scope, seriously deranged by 
 a movement of the eye piece 
 to the extent of one-tenth 
 of an inch either way. If 
 this movement makes but 
 little change, the object 
 glass is not all it ought to 
 
 FIG. 7. FIG. 8. 
 
 It will be well for the tyro 
 
 to get an experienced telescopist to make the foregoing 
 tests for him, if the services of such a one can be com- 
 manded. The following remarks J by Sir Howard Grubb, 
 of the great Dublin firm of telescope-makers, are full of 
 truth and humor, and are commended to the reader's care- 
 ful attention. Especially are the observations as to the 
 necessity of a certain education of the eye for telescopic 
 work to be diligently noted : 
 
 " It is almost impossible to give any directions which 
 will enable a tyro to detect whether his telescope is good 
 or not. It would be about as hopeless a task as to try to 
 convey to a person wholly uneducated in art, and who 
 had never seen anything but daubs, how to know a well- 
 painted picture. One great mistake which beginners fall 
 
 * The diffraction rings in these figures are necessarily represented 
 as much thicker than they are in reality, 
 f Chambers, p. 617. 
 JSee Oliver's Astronomy for Amateurs, p. 29. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 23 
 
 into, and which, it is to be feared, most text-books rather 
 encourage, is that of supposing that, because a telescope 
 of a certain size should divide such a star, the telescope is 
 necessarily bad because, when he puts his eye to it, he 
 does not see it so divided. l The most important part of 
 the telescope is the man at the small end,' said a cele- 
 brated astronomer. There is such a thing as education 
 of the eye, and even though a person have good, sharp, 
 ordinary eyesight, it by no means follows that he will see 
 nearly as much with a telescope at first as a person of very 
 ordinary sight who has educated his eye by experience. 
 
 " Text -books on the subject, by giving lists of objects 
 which are capable of being divided by different sized tele- 
 scopes, and pictures (?) of planets, etc., as they should be 
 seen, rather encourage the mistake. 
 
 " An enthusiastic amateur receives a telescope he has 
 been waiting for for months ; meanwhile he has studied 
 up the text-book on the subject, and he finds that a tele- 
 scope of the size of his should have a power of x, and 
 divide such and such stars. The moment he gets his 
 instrument into position he puts on his highest eye piece 
 and points to these objects, and great is his disgust to see 
 something like a ball of cotton wool on a flaming gas-lamp. 
 He is not told that this object can be so seen under favor- 
 able circumstances and with educated eyes, or that the 
 beautiful pictures he sees of Saturn and Jupiter are either 
 the result of a number of observations, or what was seen 
 on some exceptional occasion, and he condemns at once 
 what in experienced hands may prove an excellent instru- 
 ment. An experienced observer judges of a telescope not 
 so much by trying what stars it will divide, as by the 
 appearance of any particular stars which he is familiar 
 with." 
 
24 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 The observer may test his telescope for definition and 
 illumination by the following objects, suggested by Mr. 
 Lockyer : 
 
 A 2-inch telescope with powers of from 60 to 100 
 should exhibit : 
 
 Polaris, y Arietis, a Geminorum, 
 
 a Piscium, p Herculis, y Leonis, 
 
 .u Draconis, Urs. Majoris, Cassiopeae. 
 
 A 4-inch with powers of from 80 to 100 should exhibit: 
 
 /3 Orionis, a Lyrse, 6 Geminorum, 
 
 Hydrse, s Leonis, a Cassiopeae, 
 
 s Bootis, y Ceti, e Draconis. 
 
 Different eyes and telescopes, however, will give very 
 different results upon the above stars, y Leonis, for 
 example, would be a very severe test for a 2-inch ; while 
 ft Orionis and e Bootis have often been seen with a j-inch 
 and with even smaller apertures. 
 
 Concerning eyepieces there is little to be said. The 
 construction of them, while by no means so easy as to 
 greatly tempt the amateur to make them for himself, 
 since very accurate adjustments are required in them, is 
 still within the power of an ordinarily skilful optician, and 
 they are consequently easy to obtain and comparatively 
 inexpensive, their prices ordinarily ranging from $4.50 to 
 $8.00. The Huygenian form, or one of its modern modi- 
 fications, will of course be employed, unless the observer 
 desires to make use of a micrometer, which, it must be 
 understood, is practically out of the question for any tele- 
 scope unprovided with a driving-clock. 
 
 The materials used for telescope tubes are wood, brass, 
 steel, or a species of papier-macht for instruments up to 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 25 
 
 three or four inches of aperture ; wood or brass for the next 
 series, and frequently sheet-iron or steel for the largest 
 sizes. Our observer's telescope will probably have a tube 
 of brass possibly steel if purchased in a complete form. 
 Should he construct his own telescope, the question as to 
 the material of the tube will be an important one. Wood 
 is apt to split ; brass is very expensive. A tube made by 
 pasting alternate layers of card and calico over a wooden 
 mould, which is then withdrawn, is said by Mr. Proctor to 
 be both light and strong. This form of tube is excel- 
 lently adapted for telescopes up to two and one-half 
 inches of aperture, but for anything larger another plan 
 suggested to Proctor by Mr. Sharp, of St. John's College, 
 Cambridge, is greatly to be preferred. This is to have 
 the tube made of tin. covered with layers of brown paper, 
 well pasted and thicker towards the middle of the tube. 
 This, according to Mr. Sharp, forms a light and strong 
 telescope tube, almost wholly free from vibration. I 
 strongly recommend this plan as cheap and effective. 
 
 The inside of the tube must be colored dead black to 
 prevent the reflection of any light from it. The follow- 
 ing is the best composition for this purpose : Lampblack, 
 five parts ; finely pulverized gum-arabic, two parts ; brown 
 sugar, one part. Mix to a thick paste with water, and 
 apply with a piece of flannel. Two coats may be neces- 
 sary. The proportions should be carefully preserved, 
 since if there is too much lampblack the composition will 
 rub off, while if there is too little it will reflect light. 
 
 The above mixture adheres readily to wood or paper, 
 but not very well to metal. A tin tube may be lined with 
 brown paper previously blackened with the compound. 
 Brass may be blackened by means of a solution of one 
 drachm platinum bichloride and one grain nitrate of silver 
 
26 THE AMATEUR TELESCOPIST*S HANDBOOK. 
 
 in one and one-half ounces of water. The brass is first 
 thoroughly cleaned and then warmed, and the solution is 
 applied with a tuft of cotton. Rub till dry, and finish off 
 with a little powdered graphite, taking care not to rub 
 this latter so as to produce a polish. (M. Carey Lea.) 
 A much cheaper and equally effective way of blackening 
 brass is to clean it thoroughly and immerse it for ten 
 minutes in a ten per cent, solution of potassium sulphide. 
 The metal is then washed in water and dried, and will be 
 found to be thoroughly and permanently blackened. 
 
 It is necessary, for reasons mentioned on page 20, to 
 have the tube somewhat larger than is required for the 
 admission of the object-glass. " Stops " or diaphragms 
 pierced with apertures to transmit all the rays except 
 those falling through the extreme edges of the objective, 
 are usually placed in the tube, and serve to cut off the 
 " ragged edge " of the field of view, and as an additional 
 protection against light reflected from the interior of the 
 tube. I have never found these stops necessary if the 
 inside of the telescope is thoroughly blackened. The 
 amateur who has a telescope made under his own super- 
 vision, or who makes it himself, must be particularly care- 
 ful that the ends of the tube are cut squarely at right 
 angles with its length, to insure the proper centring of 
 all the lenses ; in fact, the ends had better be " trued " in 
 a lathe. 
 
 The eyepieces slip into a tube at the eye end of the 
 telescope, which is capable of motion back and forth for 
 the adjustment of the focus. This movement is usually, 
 and should be always, effected by means of rack-work. 
 The focusing apparatus should work smoothly and 
 closely and with as little "back-lash" as possible ; />., 
 when the movement of the button is reversed, the reverse 
 
THE AMATEUR TELESCOPIST*S HANDBOOK. 27 
 
 motion of the eyepiece should begin at once, without any 
 intermediate play of the rack-work. 
 
 The construction of a telescope, aside from its optical 
 parts, is fairly within the powers of an ordinarily skil- 
 ful amateur handicraftsman. But the student may prefer 
 to purchase his telescope complete, and it cannot be 
 doubted that when this is possible, it is by far the best 
 course for him to pursue. 
 
CHAPTER III. 
 
 THE STAND. 
 
 SCARCELY less important than a good telescope is a good 
 stand. There is not a doubt that a telescope set upon a 
 firm and steady mounting will not only give more pleas- 
 ure in its use, but will exhibit more difficult objects than 
 a larger and perhaps finer instrument set upon a rickety, 
 unsteady and clumsy stand. Such a mounting as the 
 latter will be a source of endless vexation and trouble ; so 
 let the possessor of a telescope see to it that his stand is 
 as firm as the nature of things admits. 
 
 Small telescopes are sometimes mounted on what is 
 known as the pillar-and-claw stand : an 
 upright pillar supported upon three feet. 
 A more usual and much more convenient 
 mounting is a wooden closing tripod. 
 Telescopes mounted upon such stands 
 are usually provided with two motions : 
 one in altitude, or from the horizon to 
 the zenith, and the other in azimuth, or 
 at right angles to the first. This is known 
 as the altazimuth stand. Several devices 
 have been contrived to render this system 
 of mounting convenient and reliable, 
 among which there is nothing better than 
 the plan described by R. A. Proctor,* and represented in 
 Fig. 9. 
 
 FIG. 9. 
 
 * Half-hours, p. 16. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 29 
 
 '* The slow movement in altitude," says Mr. Proctor, 
 " is given by rotating the rod h e, the endless screw in 
 which turns the small wheel at b y whose axle in turn bears 
 a pinion-wheel working in the teeth of the quadrant a. 
 The slow movement in azimuth is given in like manner 
 by rotating the rod h' e , the lantern-wheel at the end 
 of which turns a crown-wheel on whose axle is a pin- 
 ion-wheel working on the teeth of the circle c. The 
 casings at e and e', in which the rods h e and h' e' re- 
 spectively work, are so fastened by elastic cords that an 
 upward pressure on the handle h, or a downward press- 
 ure on the handle ti, at once releases the endless screw 
 or the crown-wheel respectively, so that the telescope can 
 be swept at once through any desired angle in altitude or 
 azimuth. This method of mounting has other advan- 
 tages : the handles are conveniently situated and constant 
 in position ; also, as they do not work directly on the tel- 
 escope, they can be turned without setting the tube in 
 vibration." But Mr. Proctor continues : " I do not rec- 
 ommend the mounting to be exactly as shown in the 
 figure. That method is much too expensive for an alt- 
 azimuth. But a simple arrangement of belted wheels in 
 place of the toothed wheels a and c might very readily be 
 prepared by the ingenious amateur telescopist ; and I feel 
 certain that the comfort and convenience of the arrange- 
 ment would amply repay him for the labor it would cost 
 him. My own telescope though the large toothed wheel 
 and the quadrant were made inconveniently heavy 
 (through a mistake of the workman who constructed the 
 instrument) worked as easily and almost as convenient- 
 ly as an equatorial." 
 
 The observer with an altazimuth is compelled to search 
 for every object which is not visible to the naked eye, by 
 
30 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 the aid of directions as to the situation of the object 
 with reference to visible stars. Great pains have been 
 taken in the lists of celestial objects given in this book, 
 to make these directions full and accurate ; but it must 
 be admitted that in many cases patience and time are 
 required to " pick up " the object. Still, this is the only 
 course open to the telescopist whose only means of ob- 
 servation is an altazimuth, or even an equatorial without 
 graduated circles ; and this is the class of observers for 
 which this book is principally prepared. But should the 
 amateur be fortunate enough to be able to provide him- 
 self with an equatorial mounting with graduated circles, 
 he is at once placed beyond the necessity of " fishing " for 
 objects, to use Admiral Smyth's expressive phrase, since 
 he can at once direct his telescope to the desired place. 
 
 As the equatorial mounting is incomparably superior to 
 all others, and is the one almost invariably employed by 
 professional astronomers for extra-meridional telescopic 
 work, every student of the telescope should be acquainted 
 with its principles and the method of using it. It consists 
 essentially of an axis placed parallel with the axis of the 
 earth, with another axis set at right angles to it. The 
 first of these is called the polar axis, the second the 
 declination axis. At one end of the declination axis, and 
 at right angles to it, is fixed the telescope, and at the 
 other a weight to counterpoise the telescope. As all 
 celestial objects appear to move in circles about the pole 
 of the heavens, it is evident that if the polar axis of a 
 telescope mounted as above be caused to rotate in a 
 direction the same as that of the apparent motion of the 
 stars, and at the same rate, it will continue to point to 
 any star to which it may be directed, as it describes its 
 course in the sky. If a telescope mounted on an altazi- 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 31 
 
 muth stand be tilted so that its previously upright stand- 
 ard points to the pole of the heavens, or, in other words, 
 is parallel with the earth's axis, it is plain that by pointing 
 the instrument at any given star, and rotating the standard 
 in a direction contrary to that of the earth's diurnal 
 motion, and at a corresponding rate, the telescope will 
 follow the star. This would be an equatorial in its sim- 
 plest form. 
 
 The place of a star or other object is located upon the 
 celestial sphere in the following manner : First, by its 
 distance, reckoned on the celestial equator, from the 
 vernal equinox, or as it is frequently called, the First 
 Point of Aries. This is called its Right Ascension, and is 
 usually expressed in hours, minutes, and seconds, but 
 sometimes in degrees, minutes, and seconds ; the equator 
 being divided into twenty-four hours or three hundred 
 and sixty degrees. Second, by its angular distance north 
 or south from the equator, measured on the great circles 
 passing through the poles. This is called its Declination, 
 and is invariably expressed in degrees, minutes, and 
 either seconds, or, more frequently, decimals of minutes. 
 Sometimes the second co-ordinate is stated in North 
 Polar Distance a phrase which explains itself. 
 
 Now, if the polar axis of an equatorial be rotated, the 
 end of the telescope will describe circles parallel with the 
 equator ; and if the declination axis be rotated, the end 
 of the telescope will describe great circles passing through 
 the poles. It is evident, then, that if properly graduated 
 circles be attached to these two axes, the right ascension 
 and declination of any object to which the telescope is 
 pointed may be easily ascertained ; and, conversely, if the 
 right ascension and declination of any object are known, 
 the instrument may be readily directed to it. 
 
32 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 Fig. 10 represents a portable equatorial stand. It will 
 be noted that an arrangement is provided for setting the 
 polar axis parallel with the axis of the earth, according 
 to the latitude of the place in which the instrument is 
 
 FIG. 10. 
 
 used. In large fixed stands for observatory use, the 
 position of the polar axis is permanently fixed by the 
 maker. Verniers are provided for setting and reading 
 the circles, and sometimes small microscopes for more 
 conveniently examining them. 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 33 
 
 In using the equatorial, the stand must be placed in 
 such a manner that the polar axis is parallel with the axis 
 of the earth ; that the declination circle shall read o 
 when the telescope points to the celestial equator ; that 
 the polar axis shall be in the meridian ; and that the index 
 of the right ascension or hour-circle shall read o when 
 the telescope is placed in the meridian. In scientific 
 observation these adjustments must be made with great 
 accuracy, and the reader is referred to any work on prac- 
 tical astronomy for the methods employed. A portable 
 equatorial, however unless the student is fortunate 
 enough to possess a fixed observatory will have to be 
 adjusted for each evening's observation, and minute ac- 
 curacy is hardly practicable, but the observer can with 
 but little trouble arrange his stand with sufficient cor- 
 rectness for an amateur's purposes. This is accomplished 
 as follows : 
 
 Set the instrument approximately in the meridian by 
 means of a compass or by reference to the pole-star. 
 Fix the tripod firmly, so that the base of the equatorial 
 shall be level. The following adjustments must then be 
 made : * 
 
 i. To set the polar axis parallel with the earth's axis. 
 
 Some portable equatorials possess a graduated scale by 
 which the adjustment may be made with tolerable accu- 
 racy if the base of the stand be perfectly levelled. If this 
 be wanting, the adjustment is effected as follows : Choose 
 some star whose position is known and which is at once 
 near the meridian and near the zenith. Point the tele- 
 scope to it and read the declination circle ; then turn the 
 polar axis half round, the telescope still bearing on the 
 
 * Chambers' Astronomy, pp. 653-657. 
 
34 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 star, and again read the circle. Add the two readings 
 and divide by 2, which will give the mean observed 
 declination. If the star is not near the zenith, correct 
 this mean declination for refraction. Compare the ob- 
 served declination with the true declination given by the 
 catalogue. If the observed declination exceeds the true, 
 the pole of the instrument is above the pole of the 
 heavens, and vice versa, and must be adjusted accordingly. 
 
 2. To make the index of the declination circle point to o 
 when the telescope points to the celestial equator. 
 
 Take the difference of the two readings obtained in 
 the first adjustment, and divide it by 2 ; this will be the 
 index error of the declination verniers, and they must be 
 moved to correct it unless the error is extremely small, 
 when it had better simply be allowed for in observation. 
 
 3. To set the polar axis in the meridian. 
 
 Point the telescope to some known star about six hours 
 east or west from the meridian and as nearly midway as 
 possible between the pole and the horizon. Read the 
 declination circle (correcting for refraction if practicable, 
 although this is hardly necessary for an amateur's pur- 
 poses, unless great accuracy is desired), and compare the 
 result with the value assigned in the latest catalogue 
 accessible. If the star is east of the meridian, and its 
 observed declination exceeds that given in the catalogue, 
 the lower end of the polar axis will be to the west of its 
 true place and must be moved accordingly. Should the 
 observed declination be less than that given in the cata- 
 logue, the lower end of the polar axis is to the east of its 
 true place. 
 
 Should the star observed be west of the meridian, the 
 effects of the erroneous position and the adjustments for 
 correcting it will be reversed. 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 35 
 
 4. To make the index of the hour-circle point to o when 
 the telescope is in the meridian. 
 
 If the foregoing adjustments have been carefully made, 
 this last one will be found to have been involved in them. 
 The declination axis may be set horizontal by means of a 
 level, and the verniers of the hour-circle set to zero. 
 
 There are two methods of using the equatorial. In the 
 first, a clock or watch set to sidereal time is necessary. 
 Any clock may be made to serve this purpose for the ama- 
 teur, the difference between the rate of a clock keeping 
 sidereal time and one .keeping mean time being of little 
 moment in one evening's work. The student may, how- 
 ever, regulate his clock to sidereal time, if he choose, by 
 causing it to gain 3m. 553. in twenty-four hours. Before 
 beginning observations the clock should be set to sidereal 
 time in the following manner : Turn the adjusted tele- 
 scope to some known star east of the meridian, and read 
 on the hour-circle its distance from the meridian. Sub- 
 tract this reading from the star's right ascension, and the 
 result will give the sidereal time with sufficient accuracy 
 for our purpose, and the clock may be set to mark it. Of 
 course, the student will remember that a sidereal clock 
 indicates twenty-four hours to the day, while a mean-time 
 clock indicates twice twelve. If the sidereal time exceeds 
 twelve hours, the observer may simply subtract twelve 
 from it and set his clock accordingly. 
 
 In case the star used in setting the clock is west of 
 the meridian, the circle reading is to be added to the right 
 ascension of the star to obtain the sidereal time. 
 
 Of course, in all these observations for adjustment, etc., 
 the telescope is to be pointed toward the star so that the 
 latter shall appear in the centre of the field. This is 
 most conveniently accomplished by the aid of a positive 
 
36 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 eyepiece with crossed wires in its focus ; but this is not 
 necessary. 
 
 Let us take an illustration of this method of using the 
 equatorial. Suppose we wish to find the superb red star 
 R Leporis. We find from our catalogue that the right 
 ascension of this star is 4h. 54m. 365., and its declina- 
 tion 14 58.2' south ; and we will suppose that our clock 
 indicates 6h. 56m. sidereal time. Since the right ascen- 
 sion of the star is greater than the sidereal time (which 
 expresses the right ascension of any object at that instant 
 on the meridian), we see that the star has not yet reached 
 the meridian. Accordingly we subtract the sidereal time 
 from the right ascension of our star, and find that the lat- 
 ter is 2h. im. 245. east of the meridian. This is called 
 the hour angle. The telescope is now turned to the east 
 and set to indicate this distance from the meridian on the 
 hour circle. Then setting the declination circle to 14 
 58.2' south, the star should be seen in the field. 
 
 If the right ascension of an object be less than the 
 sidereal time, it is evident that the object is west of the 
 meridian, and the hour angle will be found by subtracting 
 the right ascension from the sidereal time. 
 
 The second method of using the equatorial is simpler 
 and more convenient for the amateur, inasmuch as no 
 clock is required, although it involves, perhaps, a little 
 more trouble in circle-reading. Select some known star 
 visible to the naked eye, and note the difference between 
 its right ascension and that of the required star. If the 
 right ascension of the known star is greater than that of 
 the required star, the latter will be west of the former, 
 and vice versd. Direct the telescope to the known star, 
 and read the hour circle. Now move it east or west, as 
 the case may be, until the index of the hour circle has 
 
THE AMATEUR TELESCOPIST*S HANDBOOK. 37 
 
 measured an arc equivalent to the difference of right 
 ascensions. Set the declination circle, and the required 
 star should be found in the field. It will be found best 
 to select the known star on the same side of the meridian 
 as the required one, as the reading of the hour circle will 
 be less troublesome. 
 
 If the equatorial be not provided with a clamp in right 
 ascension (/>., to the polar axis), it will usually be well to 
 set and clamp the telescope in declination before turning 
 it on its polar axis. 
 
 The success of observations with the equatorial will 
 depend on the accuracy with which the adjustments 
 have been made, and it is always best with a portable 
 equatorial to put on the lowest power when seeking an 
 object, so as to embrace as large a field as possible. A 
 little practice and care will enable the observer to adjust 
 his equatorial expeditiously and with sufficient accuracy 
 for an amateur's purposes. A star may be followed with 
 an equatorially mounted telescope by simply turning the 
 instrument on its polar axis. An equatorial stand is 
 usually provided with an appliance to give this slow move- 
 ment in right ascension, consisting of a crown or lantern 
 wheel working upon the polar axis and provided with a 
 universal joint from which a rod leads to the observer's 
 hand. In the more elaborate and expensive equatorial 
 stands, clock-work is provided to move the telescope in 
 right ascension at a rate corresponding to that of the 
 apparent motion of celestial objects. 
 
 The prices of portable equatorial stands are given else- 
 where, but the amateur will find a description of a simple 
 stand, which he can make himself, or have constructed 
 under his own supervision, in the Astronomical Register, vol. 
 xiv., p. 35. A common equatorial may be made much 
 
3 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 more effective by having attached to it plain metal circles 
 or even stout pasteboard ones, graduated by the observer 
 himself. The student who is acquainted with the ex- 
 quisite graduation of modern astronomical circles may 
 feel dismayed at the suggestion of graduating circles for 
 himself ; but I can assure him that with patience and care 
 he can prepare circles which, if they will not enable him 
 to hit exactly upon an object, will greatly help him in 
 finding it. 
 
CHAPTER IV. 
 
 ACCESSORIES OF THE TELESCOPE. 
 
 THERE are but few of the supplementary instruments 
 used in modern astronomy which are applicable to a 
 small telescope without clock-work to drive it. Micro- 
 metric measurements, celestial photography, and, except in 
 a very limited degree, spectroscopic work, must be left to 
 those fortunate ones who possess telescopes of larger size 
 and more perfect mounting than the average amateur can 
 procure. There are two accessories, however, which every 
 telescope should possess. These are a finder and a dew-cap. 
 When observing with high powers, it is a matter of very 
 considerable difficulty to fix the telescope upon any object. 
 Practice will diminish the difficulties of this operation, 
 but not sufficiently to prevent the task's being tedious 
 and vexatious. The finder relieves this trouble at once. 
 It is a small telescope of low power, and consequently of 
 large field, attached to the telescope at its eye-end, and 
 parallel with it. It is so adjusted that any object to which 
 the telescope is pointed will appear at once in the centre 
 of its field and that of its finder. To fix the telescope 
 upon any object, all we have to do is to set the instrument 
 so that the object is visible in the centre of the finder's 
 field, which is effected with the greatest ease, and then, 
 if the adjustments have been properly made, the star will 
 be seen in the centre of the telescope's field, no matter 
 how high may be the power of the eyepiece. 
 
 The place of an object invisible to the naked eye or in 
 
40 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 the finder is often given by its position with reference to 
 certain visible stars. It frequently happens that these 
 guiding stars may be visible in the finder, and the tele- 
 scope may be readily set to the proper point by the aid 
 thus afforded. 
 
 The amateur need go to little expense to secure a 
 finder amply sufficient for his needs. A telescope of my 
 own is fitted with a small toy " spy-glass " costing fifty 
 cents, which serves its purpose as a finder to perfection. 
 Mr. Proctor suggests* that the amateur may make his 
 own finder by fastening on the two ends of a pasteboard 
 tube two lenses at a distance from each other equal to the 
 sum of their focal lengths, the object glass of, say, six 
 or eight inches focal length, and the eye-lens of one or 
 two, giving a power of from three to eight, according to 
 the lenses used. This little contrivance is fastened to the 
 telescope tube with wires and adjusted each night before 
 beginning observations, by first bringing a star to the 
 centre of the telescope's field with a low power, and then 
 setting the finder so that the star appears at the same time 
 in the centre of its field. " A card tube with wire fasten- 
 ings," says Mr. Proctor, "such as we have described, may 
 appear a very insignificant contrivance to the regular 
 observer with his well-mounted equatorial and carefully 
 adjusted finder. But to the first attempts of the amateur 
 observer it affords no insignificant assistance, as I can 
 aver from my own experience. Without it a superior 
 finder being wanting our ' half -hours ' would soon be 
 wasted away in that most wearisome and annoying of all 
 employments, trying to ' pick up ' celestial objects." 
 
 Another necessity to the telescopist who makes out- 
 
 * Half-hours , p. 2O. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 door observations is a dew-cap. Glass is an excellent 
 radiator of heat, and the atmosphere quickly deposits dew 
 upon it an effect from which an object glass needs pro- 
 tection. The dew-cap is a device to afford this protection, 
 and is furnished regularly by some makers with every 
 telescope. It consists of a tube of metal or pasteboard 
 blackened inside and placed over the objective end of the 
 telescope so as to project from eight to twelve inches 
 beyond the object glass. The amateur can easily make 
 this for himself and should invariably use it when observ- 
 ing out of doors. 
 
 An instrument known as the diagonal eye-tube is some- 
 times used for observing objects at high altitudes. This 
 consists of two tubes set at right angles with each other 
 and containing at the elbow either a reflector of speculum 
 metal or, what is infinitely bet- 
 ter, a right-angled prism. 
 
 The rays from the object are 
 reflected (with great loss of 
 light) from the mirror at AB, or 
 (with scarcely any loss of light) D 
 from the longest side of the 
 right-angled prism ABC, and 
 viewed by the eye-piece at D, in 
 the usual manner. The diago- 
 nal eye-tube is not to be confounded with the diagonal 
 eye-piece, in which the change of direction of the light is 
 accomplished between the lenses of the eye-piece. 
 
 This contrivance will be found very useful for observ- 
 ing objects near the zenith, or indeed at any elevation 
 above fifty or sixty degrees. 
 
CHAPTER V. 
 
 THE CARE OF THE TELESCOPE. 
 
 As a valuable and delicate instrument the telescope 
 demands, and should receive, the most solicitous care. 
 In particular does the object glass require the most ten- 
 der treatment. It should be kept covered with its cap 
 whenever it is not in actual use ; the dew-cap should 
 never be forgotten ; and the glass should never be brought 
 from a cold into a warm atmosphere without first cover- 
 ing it to prevent its becoming bedewed. If the damp 
 gets between the glasses it will produce a fog a sweat, 
 in optician's language and, according to Proctor, even a 
 seaweed-like vegetation, by which a valuable glass may 
 be ruined. Should any moisture unluckily get upon the 
 object glass, the telescope must be put in a warm place 
 until the enemy has fled. 
 
 When it is necessary to clean the object glass and it 
 should only be touched when cleaning is necessary a 
 soft camel's-hair brush should first be used for removing 
 the coarser particles of dust, which may be followed by a 
 very careful sweeping with either a piece of very fine clean 
 chamois-skin, or, better still, an old soft silk handkerchief. 
 Mr. Chambers prefers an old but fine cambric handker- 
 chief. Mr. Franks recommends soft tissue paper aided 
 by the breath. A little space near the edge of the glass 
 is first cleaned, and from that point the dust is gently 
 swept away. But let it be noted that a few specks of dust 
 are of much less moment than irremediable scratches, and 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 43 
 
 polished optical glass scratches very easily. Should any 
 " refractory stains " get upon the object glass, they may 
 be removed by a few drops of alcohol on perfectly clean 
 absorbent cotton ; but, as Mr. Chambers dryly observes, 
 a careful observer will never allow any refractory stains 
 to get upon his object-glass. Should fine dust ever cake, 
 as it sometimes will, upon the glass, breathe on it and 
 wipe very gently from the edges with a soft cloth, which 
 is then thrown away. This may sound alarming, but it is 
 the precept of no less high an authority than Sir Howard 
 Grubb. 
 
 Everything used for cleaning lenses should be kept in 
 a tightly closed box when not in use, to preserve it from 
 dust. 
 
 Never touch the polished surface of any lens with 
 your fingers. The insensible perspiration, always present 
 in small quantities, appears to have a corroding effect 
 upon optical glass, and will destroy its polish. 
 
 All of the foregoing remarks as to cleaning lenses apply 
 to eyepieces as well as to object glasses. Particularly 
 must it be remembered that every scratch or speck on 
 the field-glass of a negative eyepiece will appear in a 
 magnified form on looking through the eyeglass. Eye- 
 pieces should be kept, when not in use, in a dust-tight 
 box ; one provided with compartments is by far the best. 
 
 Under no circumstances should the two glasses com- 
 posing the objective be separated or taken out of their 
 cell by the amateur. Should circumstances make it nec- 
 essary to separate them, let it be done by the maker or 
 by a competent optician : otherwise the glass may be 
 rendered worthless. Another rule, with an example, is 
 given by Mr. Proctor, which I will quote in his own 
 vigorous language : " Suffer no inexperienced person to 
 
44 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 deal with your object glass. I knew a valuable glass 
 ruined by the proceedings of a workman who had been 
 told to attach three pieces of brass round the cell of the 
 double lens. What he had done remained unknown ; but 
 ever after a wretched glare of light surrounded all objects 
 of any brilliancy." 
 
 Should the brass-work of the telescope or stand become 
 dull or dirty, it may be cleansed with a piece of chamois- 
 skin moistened with sweet-oil. Care should be taken in 
 cleaning an equatorial stand, not to press hard upon the 
 circles lest they be bent out of "true." For protecting 
 bright metal surfaces from oxidation, and also for lubri- 
 cating purposes, ordinary vaseline is by far the best 
 preparation, as it is free from the gumminess which is apt 
 to attach to common oils. 
 
CHAPTER VI. 
 
 THE USE OF THE TELESCOPE. 
 
 THE amateur who possesses no observatory will find it 
 by far the best plan to make all his observations out of 
 doors. If a telescope is mounted in a house, the move- 
 ment of any person about any part of the building will 
 cause the instrument to vibrate, especially when high 
 powers are in use. In regular observatories it is cus- 
 tomary to mount the equatorial on a pier of solid ma- 
 sonry to prevent this very difficulty. Moreover, when 
 the telescope is used at a window, the observer will be 
 troubled greatly by a wavering of the atmosphere before 
 the object glass. This annoyance will be considerably 
 lessened if the temperature of the room is the same as 
 that of the outer air, but such a condition is not easily 
 attained. 
 
 Observations of all celestial objects, except those so 
 near the horizon that the observer can stand upright when 
 viewing them, should be made while comfortably seated ; 
 and this not so much for comfort's sake as for clearness 
 of vision. There is no doubt that a constrained or un- 
 comfortable position decidedly affects the power of the 
 eye in telescopic work. Specially constructed observing 
 chairs are in use in observatories, but the amateur will 
 need only a common chair and a stool. A small but 
 strong step-ladder will also prove useful. 
 
 I must not omit to warn the reader of the importance 
 of being warmly clad for out-door observation in winter. 
 
46 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 The use of the telescope involves little bodily motion ; 
 while looking through it the whole person is kept as still 
 as possible ; and the result is that a temperature which 
 would be regarded as mild for a walk may chill the body 
 thoroughly in a short time while at work with the tele- 
 scope. A severe and perhaps dangerous cold may thus be 
 taken. So let the observer on all winter nights, and on a 
 very large proportion of spring and autumn ones, put on 
 his heaviest great-coat, and if the ground be at all damp, 
 overshoes as well. I wish to impress the student with 
 the importance of these precautions. 
 
 Should artificial light be needed for consulting a book 
 or map, or for looking at the circles of an equatorial, the 
 observer should use a bull's-eye lantern with a slide, as 
 he is thus enabled to throw a light on the object without 
 dazzling his eyes, and the light may be cut off with the 
 slide when not needed. It is a good plan to cover the 
 bull's-eye with a piece of thin red silk or red paper, since 
 red light is less trying to the eyes than white. A very 
 good substitute for the bull's-eye lantern is a little flat tin 
 lantern with a red glass front and having a door by which 
 all light may be cut off. Such a lantern is commonly sold 
 by dealers in photographic materials. 
 
 The novice is apt to assume that a clear bright night is 
 necessarily the best for telescopic work, but such is not 
 always the case. Some brilliant nights, while available 
 for good work on the nebulae, are characterized by very 
 poor definition, and are practically worthless for observa- 
 tions on the planets and double stars. This, I think, may 
 be especially noted with regard to Saturn, whose rings I 
 have seen go through the most extraordinary gyrations on 
 an apparently superb night. On the other hand, a hazy 
 night often gives very beautiful definition, especially in 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 47 
 
 the case of the planets. A remarkable instance of this is 
 the discovery by Professor Bond of the inner dusky ring 
 of Saturn on a night so hazy that none but the larger 
 stars were visible to the naked eye. 
 
 Several devices are at times made use of for improving 
 the defining power of the object glass when employed 
 upon close double stars or other objects needing particu- 
 larly good definition. One of these is to " stop down " 
 the glass ; in other words, to diminish its aperture by 
 means of a screen of cardboard or similar material 
 pierced with a circular opening of the desired size. This 
 is sometimes particularly useful in observing Venus. 
 Another device, recommended by Sir John Herschel, is 
 to fix a disk of cardboard having a diameter of from one- 
 fifth to one-half that of the object glass centrally in front 
 of the glass. This will increase the separating power of 
 the objective, and will be occasionally useful, although it 
 increases both the number and the breadth of the diffrac- 
 tion rings around the image. Mr. Dawes recommends his 
 own curious plan of covering the whole object glass with 
 perforated cardboard such as is (or was) employed for 
 worsted work ; or, should the object be too faint to bear 
 such treatment, with a piece of cardboard pierced with 
 circles of equal size (about one-fifth of an inch in diam- 
 eter), arranged in concentric circles. 
 
 All these contrivances may be useful at times, but as a 
 general rule the possessor of a small telescope cannot 
 afford to lose any light. 
 
 To get the eye in condition for use at the telescope, it 
 is well for the observer to remain in the dark for some 
 little time before beginning work. If after some time 
 spent in observation it is desired to scrutinize a difficult 
 object, it will be very useful to turn the eyes toward a 
 
48 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 dark place, or cover them with the hand for a time, to 
 permit the pupils to dilate. An instance of the ad- 
 vantages of this plan is the rediscovery by Sir John 
 Herschel of the satellites of Uranus, which he accom- 
 plished after keeping his eyes in darkness for a quarter 
 of an hour.* 
 
 If the stand of a telescope is at all unsteady, it is an 
 excellent plan to point the instrument not directly on the 
 object that is to be viewed, but a field, or even two, pre- 
 ceding the object, and allow the diurnal motion of the 
 earth to carry the image across the field. This will per- 
 mit the telescope to settle down into perfect steadiness 
 before the object comes in view. The finder will afford 
 great help in carrying out this expedient 
 
 A word should be said concerning the focusing of the 
 telescope. The usual method with novices is to turn the 
 rack-button slowly until the image appears sharp. As a 
 result it is hardly ever turned enough, and the eye is 
 strained. The proper way is to turn the button back and 
 forth, bringing the eye piece decidedly outside and inside 
 of the focus each time ; and after a few turns it will be 
 found that a certain degree of turning brings it equally 
 on each side of the focus. Make the object equally indis- 
 tinct on both sides, and give a half turn, which brings the 
 eye piece to the true focus. Practice will speedily make 
 perfect in this operation. f 
 
 The beginner with the telescope is very apt to make 
 the same mistake as does the beginner with the micro- 
 scope, and that is in a tendency to use too high powers. 
 In examining very close doubles a high power must, of 
 course, be used ; the same is true of the more minute 
 
 * Proctor. -J- Sir Howard Grubb. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 49 
 
 study of the planets ; but for all other observations a 
 lower power is far better. A high power, moreover, 
 brfngs out all defects in the object glass, the stand, and 
 the state of the atmosphere ; and the field is made so 
 small that the object passes very quickly out of it by the 
 rotation of the earth. An object sends a certain amount 
 of light through the telescope, and magnifying any object 
 having an apparent diameter lessens its light, since it 
 spreads the image over a larger space. For this reason 
 powers beyond a certain limit are perfectly useless in the 
 examination of nebulae. Hints as to the powers to be 
 employed in particular cases will be given further on, and 
 the reader is referred to Chapter I. for a table of the 
 highest powers that should be commonly used with given 
 apertures. 
 
 Familiarity with the constellations is, of course, a 
 requisite of the first importance in an astronomer ; and it 
 is believed that the arrangement adopted in this book, of 
 grouping the telescopic objects of the heavens according 
 to the asterisms in which they appear, will conduce 
 greatly to a full and satisfactory study of the constella- 
 tions singly. A set of good star-maps is perhaps the 
 very first book that the astronomer needs. For merely 
 the delineations of the constellations and the relative 
 positions of the stars, any of the standard maps will be 
 sufficient : Hind's, in Keith Johnson's Atlas of Astron- 
 omy, the Royal Astronomical Society's maps, those pub- 
 lished by the Society for the Diffusion of Useful Knowl- 
 edge, and Heis's Neuer Himmels Atlas are all of the high- 
 est class. The well-known and inexpensive maps accom- 
 panying Burritt's Geography of the Heavens are also 
 fairly good. But for locating the planets in their course, 
 4 
 
50 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 either for purposes of study or (in the case of Uranus 
 and Neptune) for telescopic observation, the above maps 
 are not suited, since, owing to precession, they are out "of 
 date. I therefore recommend the student to supply him- 
 self with R. A. Proctor's admirable maps or Klein's Star 
 Atlas, recently published by the Society for Promoting 
 Christian Knowledge. This latter is a work of much 
 value, although unsuited for consultation by lantern 
 light, since the lettering and numbering of the stars, 
 etc., and the names and boundaries of the constellations 
 are printed in a faint red. Both Proctpr's and Klein's 
 Atlases are constructed for the year 1880, and will remain 
 sufficiently accurate for our use for twenty or thirty years 
 to come. 
 
 In studying the constellations the observer should ac- 
 custom himself to estimate by the eye distances in degrees 
 on the celestial sphere. There are three standards of 
 measurement provided in the heavens. The length of 
 the belt of Orion is (speaking roughly) three degrees ; 
 the distance from a to /3 Ursse Majoris (the well-known 
 " Pointers ") is five degrees ; and the average apparent 
 diameter of the moon is half a degree. By practice the 
 observer will soon acquire the power of measuring dis- 
 tances by these celestial measuring-rods with very con- 
 siderable accuracy. 
 
 If the student is at all near-sighted (as most modern 
 students are), he will find it very helpful and pleasant to 
 use an opera-glass in studying the constellations. I al- 
 ways make use of a binocular field-glass of one and seven- 
 eighths inches aperture and embracing a field about four 
 degrees in diameter. The larger clusters the Pleiades, 
 the Hyades, Praesepe, and Coma Berenices are peculiarly 
 beautiful in such a glass ; and no one who has not tried 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 51 
 
 this method of studying a constellation can imagine the 
 pleasure and ease afforded by it.* 
 
 Better than star-maps for some reasons is a good mod- 
 ern celestial globe. With this classic instrument the 
 student can perform many problems which are of impor- 
 tance to him in his astronomical work, such as ascertain- 
 ing quickly and easily the time of the rising, culmination, 
 and setting of any star or planet, and the accurate locat- 
 ing of any telescopic object which may not be marked 
 upon the globe. The little machine known as Whitall's 
 Planisphere, while of small merit as a map, will also be 
 found very useful, provided the observer does not live too 
 far away from the latitude for which the Planispehre is 
 especially adapted, namely, 4o-5o. 
 
 Next in importance to the star-maps among the astron- 
 omer's working books is an Ephemeris. Many of the 
 popular almanacs contain much useful astronomical mat- 
 ter ; but I strongly recommend the student to procure 
 the Nautical Almanac of his own country. This gives in- 
 formation that is invaluable to the astronomer : the posi- 
 tion of the sun, moon, and planets for every day of the 
 year, the eclipses and occultations for the year, the posi- 
 tions of Jupiter's satellites for every day, etc. ; in short, 
 all the phenomena which can profitably occupy the atten- 
 tion of the telescopist. 
 
 * See Mr. Serviss's pleasant little book, Astronomy with an 
 Opera-glass. 
 
CHAPTER VII. 
 
 OBSERVATION. STARS, NEBULA, THE SUN AND MOON. 
 
 THE tyro must remember that successful observation 
 with the telescope requires practice and a certain training 
 of the eye. It is not at all unlikely that he may ex- 
 perience some disappointment at the outset of his work 
 by failing to see objects which he has been taught will 
 be visible with such an aperture and such powers ; and 
 also by the difference between what he may expect to see 
 and what he actually does see. Let him not be dis- 
 heartened, nor let him hastily condemn his telescope; but 
 rather let him persevere, practising on the easier doubles 
 and the more conspicuous nebulae ; and he will find that 
 in a comparatively short time he will be able to detect 
 objects of a minuteness and faintness which would have 
 rendered them quite invisible to him at first. On this 
 subject I again refer the reader to Sir Howard Grubb's 
 remarks in Chapter II. 
 
 The eye should be steadily fixed on the object under 
 observation ; and it will be noticed that details will fre- 
 quently come out at intervals which are indistinct or even 
 invisible in the mean time. This may be especially noted 
 of the belts of Jupiter and Saturn when working with a 
 small aperture. 
 
 In scrutinizing a difficult object it will sometimes be 
 found helpful for the near-sighted observer to take off 
 his eyeglasses or spectacles, altering the focus of his 
 telescope to meet the change. Occasionally the slight 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 53 
 
 additional loss of light caused by another glass between 
 the eye and the image may just prevent the sight of an 
 object which will become visible when the glass is re- 
 moved. I have several times experienced this when ob- 
 serving nebulae. 
 
 A very minute star may often be seen by directing the 
 eye not directly upon it, but to another quarter of the 
 field ; the little star is thus seen out of the corner of 
 the eye, so to speak. This familiar fact proves very use- 
 ful in the perception of very small comites. 
 
 I append certain directions which the observer will 
 note with regard to observations upon different celestial 
 objects. It is, of course, not within the purpose of this 
 little work to treat minutely of these objects, but only to 
 give such points as may be necessary to the amateur tel- 
 escopist who proposes to study them with humble instru- 
 mental means. 
 
 THE [FIXED STARS. In the lists given in this book I 
 have followed Admiral Smyth in his estimate of the col- 
 ors of stars ; but I must warn the student that these state- 
 ments concerning color are often rather fantastic, espe- 
 cially with small apertures, which give much less idea of 
 color in a star than do larger ones. When the judg- 
 ments of observers have differed greatly on this subject, 
 I have stated the opinion of the dissenters from Admiral 
 Smyth. 
 
 The powers to be employed upon double stars will be 
 best learned by experiment. They differ in proportion to 
 the distance and brilliancy of the components. Some 
 may be readily seen with the lowest powers, while others 
 will demand the highest powers that a small telescope 
 will bear. Here, as with other objects, the best power to 
 use is the lowest that will effectually do the work. By a 
 
54 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 number of experiments Mr. Dawes ascertained that the 
 closest double star which a i-inch glass could separate 
 was one in which the distance between the components 
 was 4.56"; and he devised the following empirical form- 
 ula for ascertaining the separating power of different 
 apertures : 
 
 Separating power in seconds of arc = ^^. : 
 
 aperture in ins. 
 
 The separating power of different apertures would then 
 be as follows : 
 
 Least Separable Least Separable 
 
 Aperture. Distance. Aperture. " Distance. 
 
 a a 
 
 I 4.56 4 1.14 
 
 1.6 2.85 4.5 i. 01 
 
 2.0 2.28 5.5 O.pT 
 
 2.5 1.82 5.5 0.83 
 
 3.0 1.52 6.0 0.76 
 
 3.5 1.30 6.5 0.70 
 
 Mr. Chambers recommends a power of 120 on a 3-inch 
 glass for doubles of a distance from 3" to 12" ; of 240 for 
 any closer ones ; and of less than 120 for any doubles of 
 greater distance than 12". 
 
 NEBULAE. These weird and most fascinating objects 
 must be reluctantly admitted to be, for their full apprecia- 
 tion, rather beyond the powers of a small telescope. A 
 large light-collecting power in other words, a large 
 aperture is needed for their satisfactory study. But the 
 mere sight of a nebula has a mysterious and awe-inspiring 
 charm about it ; and all the nebulae listed in this book are 
 at least visible with an aperture of three inches at most. 
 Moreover, there is a singular circumstance in this connec- 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 55 
 
 tion, mentioned by d' Arrest ; which is that a nebula is 
 sometimes seen with a small aperture which is invisible 
 with a large one. M. d'Arrest states that Tempel's nebula 
 in the Pleiades is perceptible in the finder of the n-inch 
 refractor at Copenhagen, but invisible in the telescope 
 itself. * 
 
 Low powers must almost invariably be used upon 
 nebulae ; every enlargement of these objects diminishes 
 the quantity of light available for seeing them. 
 
 THE SUN. It seems unlikely that any one of ordinary 
 sense should need to be warned not to look at the sun 
 through a telescope without the employment of some 
 means to protect the eye against the blazing light of that 
 tremendous orb. And yet no less great an astronomer 
 than Sir William Herschel lost an eye by making that 
 mad attempt. So let the student be earnestly admon- 
 ished to take the best precautions to shield his eyes when 
 engaged in solar observation. The plan commonly 
 adopted is to use the sun-shades which are usually fur- 
 nished with eye pieces, the colors of which are either neu- 
 tral-tint, blue, or red. But with an aperture of more than 
 two inches there is danger that if observation be pro- 
 longed the shading glass will crack and the light of 
 the sun be transmitted with perhaps disastrous effect. 
 Red shades are less liable to this calamity than the blue 
 or neutral ones, but even they are not altogether free 
 from danger, and, moreover, a red glass is not a pleasant 
 medium through which to view the sun. The observer 
 may stop his object glass down to two inches or under, 
 or he may turn the instrument away from the sun at 
 short intervals to allow the eye piece and the air within 
 
 * Webb, Celestial Objects, p. 399. 
 
56 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 the tube to cool off ; or if he possesses a terrestrial eye- 
 piece, he may use it for solar observations. The addi- 
 tional lenses which this eyepiece interposes between the 
 object glass and the eye absorb some of the light and 
 heat, and much lessen the danger to the shade glass. 
 This is the method recommended by Mr. Proctor, and to 
 the advantages of which I can bear testimony. But if 
 the observer proposes to devote much time to the sun, 
 he will find that one of the forms of the diagonal solar 
 eyepiece will repay him for the expense incurred in its 
 purchase. One of these instruments consists essentially 
 of a perfectly plane piece of plate-glass set at an angle of 
 forty-five degrees with the optical axis of the telescope, 
 so as to reflect the sun's rays at a right angle with that 
 axis. The under side of this reflector is ground, in order 
 to avoid a double reflection, and a very large proportion of 
 the sun's light and heat passes through it. That portion 
 which is reflected is viewed through an eyepiece with a 
 lighter shade, set at right angles with the optical axis.* 
 
 In another and more commonly used solar diagonal 
 eyepiece, a front-surface-reflecting prism or wedge is sub- 
 stituted for the plane reflector. This reflects only about 
 one-thirtieth of the sun's light, and scarcely any of its heat. 
 
 These devices enable the observer to keep his telescope, 
 directed to the sun for an indefinite period. 
 
 Perhaps the best of all methods for studying the sun is 
 simply to throw its image upon a sheet of clean white 
 paper or cardboard. The ingenious amateur will easily 
 contrive a method of supporting this cardboard. One 
 favorite plan is to make a light cone or pyramid with its 
 small end attached to the eye-end of the telescope, the 
 
 * Noble, Three-inch Telescope, p. 9. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 57 
 
 framework being made of stiff wire or, better, bamboo, 
 and covered with black calico or cambric. The bottom 
 of this pyramidal box holds the cardboard sheet on 
 which the image is received. An opening in the side of 
 the pyramid enables the observer to see the image. A 
 photographer's focusing cloth placed over the observer's 
 head will keep off extraneous light and enable him to 
 study with ease and pleasure the phenomena of the solar 
 surface. 
 
 The most prominent of these phenomena are, of course, 
 the spots. These are never, according to Mr. Howlett, 
 less than three seconds in length or breadth, and are con- 
 sequently fully within the grasp of a small telescope. 
 Each spot which can be sufficiently magnified for such a 
 purpose will be seen to consist of a central black portion, 
 or umbra, surrounded by a region less dark, called the 
 penumbra. These spots are depressions or openings in 
 the sun's photosphere, or outward envelope. Facula are 
 supposed to be elevations or ridges on the photosphere. 
 They are streaks and spots of light, usually in the neigh- 
 borhood of dark spots, and are sometimes of very singu- 
 lar form. 
 
 To catch the mottling or graining of the solar surface, 
 Captain Noble recommends the shifting about of the tele- 
 scope so as to cause the sun's image to move about in the 
 field, when " the eye will soon receive the impression of a 
 roughness or grain upon the sun's surface, akin to that 
 of a piece of magnified loaf sugar." 
 
 THE MOON. With a sense of relief we turn away from 
 the glare of the sunlight, with its revelation of the com- 
 mon things of earth, to the quiet and mystic beauty of 
 the "astronomer's day." Our lovely satellite presents 
 an ever varying and ever interesting subject of study, 
 
58 THE AMATEUR TELESCOPIST*S HANDBOOK. 
 
 and I much regret that the limits of this book forbid as 
 full a description of the moon as I should like to present 
 to the reader. 
 
 The moon should be carefully scanned by the observer 
 as she passes through her phases, and it is recommended 
 that he try to make two observations each evening, one 
 as early and the other as late as possible. In this way he 
 will be able to observe the gradual creeping of the sun- 
 light over the craters and mountains of the "spotty globe," 
 and to note the extraordinary effects produced by the 
 gradual advance or retreat of the terminator or the irregu- 
 lar line marking the limit to which the illumination 
 reaches. " The outlying and isolated peak of some great 
 mountain chain becomes gradually larger and is finally 
 merged into the general luminous surface ; great cir- 
 cular spaces, enclosed with rough and rocky walls many 
 miles in diameter, become apparent ; some with flat and 
 perfectly smooth floors variegated with streaks ; others 
 in which the flat floor is dotted with numerous pits, or 
 covered with broken fragments of rock. Occasionally a 
 regularly formed and unusually symmetrical circular for- 
 mation makes its appearance, the exterior surface of the 
 wall bristling with terraces rising gradually from the 
 plain, the interior one much more steep ; and instead of 
 a flat floor, the inner space is concave or cup-shaped with 
 a solitary peak rising in the centre. Solitary peaks rise 
 from the level plains and cast their long, narrow shadows 
 athwart the smooth surface. Vast plains of a dusky tint 
 become visible, not perfectly level, but covered with 
 ripples, pits, and projections. Circular wells which have 
 no surrounding wall dip below the plain, and are met with 
 even in the interior of the circular mountains and on the 
 tops of their walls. From some of the mountains great 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 59 
 
 streams of a brilliant white radiate in all directions and can 
 be traced for hundreds of miles. We see again great 
 fissures almost perfectly straight and of great length, 
 although very narrow, which appear like the cracks in 
 moist clayey soil when dried by the sun." * 
 
 The student who desires to go minutely into the study 
 of the topography of the moon should procure Neison's 
 admirable book on this subject. For an amateur's pur- 
 poses the brief study given here may perhaps suffice. An 
 excellent map of the moon is given in Webb's Celestial 
 Objects and maybe obtained separately for eighteen pence 
 from Longmans, Green & Co., of London and New York. 
 This map is given in a reduced form in Noble's Three- 
 inch Telescope, and from it the guide-map presented in 
 this book is prepared. 
 
 In the following brief descriptions of lunar objects I 
 have simply used the words above, below, right, left, etc., 
 rather than employ the points of the compass according 
 to the usage of selenographers. It may be well to state, 
 however, that in maps of the moon as seen in an inverting 
 telescope (and such is our guide-map), the North and 
 South points occupy the bottom and top of the map 
 respectively, while the East and West points are at the 
 right and left respectively, as in terrestrial maps. 
 
 The map represents the moon at the period of its mean 
 libration, and the expressions above, below, etc., must be 
 understood as describing the relative positions of objects 
 at that period. 
 
 i. TYCHO. We begin with what Webb calls "the met- 
 ropolitan crater of the moon." This will be instantly 
 
 * From a paper by Breen, in Popular Science Monthly ', quoted by 
 Proctor, Half-hours, p. 93. 
 
60 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 recognized as the most conspicuous object on the face of 
 our satellite when full a crater from which radiates a 
 vast system of rills or rays extending over at least a quar- 
 ter of the disk. It is visible to a sharp eye without opti- 
 cal aid, has a diameter of 54^ miles, and its walls rise at 
 the highest point to 17,000 feet. Its central hill is be- 
 tween 5,000 and 6,000 feet high. To its left is Pictet, to 
 the left of which is Saussure. To the right of Tycho is 
 Heinsius. Above and a little to the left is Street, above 
 which is Maginus a noble formation which utterly dis- 
 appears at full moon. 
 
 2. PLATO. A grand ring-plain 60 miles across. 
 Under it extends the Mare Frigoris; above it to the 
 right is the Mare Imbrium, and to the left the Mare 
 Serenitatis. Plato was called by Hevelius the " Greater 
 Black Lake," and, with the exception of Grimaldi, is the 
 darkest part of the moon's surface. 
 
 3. LINNE. A small crater in the Mare Serenitatis, 
 where indications of recent volcanic action have been 
 thought to be seen ; an opinion favored by Proctor and 
 Webb. 
 
 4. ARISTARCHUS. The most brilliant portion of the 
 moon's surface. " Its peaks shine often like stars when the 
 mountain is within the unillumined portion of the moon's 
 surface." (Proctor.) At times " its lustre is actually un- 
 pleasant to the eye, even in a three-inch telescope." 
 (Noble.) Its central mountain seems even brighter than 
 the walls of the crater. Immediately to the right of it 
 lies Herodotus. 
 
 5. MESSIER. Two craters from which extend two sin- 
 gular straight streaks, giving the object an appearance 
 somewhat like a comet, and suggesting its name from the 
 famous French "comet ferret," M. Messier. 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 6l 
 
 6. THE ALPS. A grand range of mountains strongly 
 resembling terrestrial systems. The chain is interrupted 
 by a vast valley between 80 and 90 miles long, and from 
 3^ to 6 miles across. 
 
 7. THE APENNINES. A magnificent range resembling 
 that of the Alps, but including higher peaks, and culmi- 
 nating in Mount Huygens, 20,000 feet high. This chain 
 is one of the portions of the moon which frequently pro- 
 ject beyond the terminator so strikingly at times that a 
 keen eye may perceive it without a telescope. The range 
 terminates in the splendid crater Eratosthenes. Above 
 and to the left of Mount Huygens lies the mare called 
 Middle Bay. 
 
 8. FRASCATORIUS. A curious " bay " at the upper end 
 of the Mare Nectaris. Below it and to its right, on the 
 edge of the mare, is Beaumont. 
 
 9. POSIDONIUS. One of the largest ring-plains on the 
 moon, 62 miles in diameter, with a fine central crater. 
 It lies in the Mare Serenitatis, and has a smaller ring- 
 plain (Chacornac) attached to it toward the left. 
 
 10. n, 12. THEOPHILUS, CYRILLUS, CATHERINE. A 
 grand triple group. Study it carefully. Note the two 
 mountains in Cyrillus and the crater on its wall. The- 
 ophilus is the deepest crater in the moon, its wall rising, 
 in places, 18,000 feet above the bottom. Its diameter is 
 about 64 miles, and when the moon is about five days old, 
 the illuminated portion of the summit of Theophilus is 
 projected beyond the terminator as a luminous ring. 
 
 13, 14, 15. ARZACHEL, ALPHONSUS, PTOLEMY. Another 
 splendid triple group, the components being, respectively, 
 6 5i> 8 3> an d 115 miles in diameter. Alphonsus contains 
 a mountain, and Arzachel a mountain and a crater. On 
 the upper" right-hand portion of the wall of Alphonsus 
 
62 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 will be seen the fine crater Alpetragius, and at the lower 
 part of Ptolemy is the equally fine Herschel. Above and 
 to the right of Arzachel is an enormous straight cliff 
 known as u Straight Wall " or Range, and sometimes 
 called The Railway. 
 
 1 6. Pico. An isolated peak in the Mare Imbrium, 8,000 
 feet high, and casting an extraordinarily long shadow 
 under oblique illumination. It is directly above Plato. 
 To its right and at about the same distance from Plato 
 is the curious little group called the Teneriffe Mountains. 
 
 17. COPERNICUS. A magnificent ring-plain, one of the 
 finest, if not the finest, in the moon. It is 56 miles 
 across, and is one of the centres from which radiate the 
 curious light-rays or rills. Below it is a pretty pair of 
 craters, the larger of which is known as Gay-Lussac, and, 
 more than twice as far away, lower and more to the right, 
 is Tobias Mayer, with a more recently erupted crater on 
 its left side. Between Gay-Lussac and Tobias Mayer is 
 Mount Carpathus. 
 
 18. MOUNT HUYGENS. See Apennines. 
 
 19. EUCLID. A small crater surrounded by a sort of 
 nimbus. It is in an island, so to speak, in the Oceanus 
 Procellarum. 
 
 20. VITELLO. A most curious formation at the upper 
 end of the Mare Humorum. It consists of a ring enclos- 
 ing another one, from the centre of which rises a hill 
 nearly 1,700 feet high. It is connected by a curving 
 ridge with the crater called Doppelmayer. 
 
 21. THE DORFEL MOUNTAINS. An enormous range, 
 almost on the limb of the moon, and sometimes strikingly 
 seen in profile. The three chief peaks probably exceed 
 26,000 feet in height. Just below them is the enormous 
 ring-plain Bailly. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 63 
 
 22. WARGENTIN. A most singular object resembling 
 an extremely truncated column 54 miles across. Webb 
 compares it to a large thin cheese. It appears to be a 
 crater rilled to the brim with lava. Just below it is the 
 grand ring- plain Schickard, about 153 miles in diameter. 
 
 23. AIRY. See 28. 
 
 24. ERATOSTHENES. A splendid crater with three cen- 
 tral peaks. It is 37^ miles across, and terminates the 
 chain of the Apennines. 
 
 25. PICCOLOMINI. A fine ring-plain 57^ miles across. 
 Its wall is somewhat complex and has on its right edge 
 a tower about 15,000 feet high. The Altai Mountains 
 start from Piccolomini and terminate in Tacitus. Their 
 principal summits rise to about 13,000 feet. Along their 
 right side are the craters Pons and Fermat, and on their 
 left is Polybius, just above Catherine. The group of 
 huge craters- to the right of Fermat is Sacrobosco. 
 
 26. GRIMALDI. An immense dark plain about 148 
 miles long by 129 wide. It is probably the darkest part 
 of the moon. Immediately below it is the triple group 
 Lohrmann, Hevel, and Cavalerius ; to its right, and below, 
 is Riccioli ; to its left, Damoiseau, and above it, Rocca. 
 
 27. ARCHIMEDES. A fine but comparatively shallow 
 ring-plain 50 miles across. A fine object in the rising 
 or setting sun. On a level with its lowest part and to 
 the left is Autolycus, below which is Aristillus. These 
 two craters are surrounded by remarkable radiating 
 banks like lava streams. 
 
 28. 29, 30, 31. WALTER, REGIOMONTANUS, PURBACH, 
 LACAILLE. Four ring-plains at the upper end of a curi- 
 ous chain of craters, of which the last but one is Airy. 
 
 3 2 > 33> 34- PARRY, BONPLAND, FRA MAURO. A fine 
 triple group. 
 
64 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 35. MARE CRISIUM. An immense plain, one of the 
 most conspicuous objects on the moon. From the upper 
 border a huge cape (Promontorium Agarum) projects 
 about 50 miles into the mare. Just to the right of the 
 'mare is the brilliant little crater Proclus. 
 
 36. SINUS IRIDIUM (Bay of Rainbows). A beautiful 
 formation at the lower part of the Mare Imbrium. Beer 
 and Madler pronounce this " perhaps the most magnifi- 
 cent of all lunar landscapes." The capes at the right and 
 left are respectively capes Heraclides and Laplace. 
 
 37. CLAVIUS. A splendid crater, peculiarly impressive 
 in sunrise. It is more than 142 miles broad, and is 
 " encompassed by a wall damaged by successive explo- 
 sions, but still portentously high and steep, attaining 
 17,300 feet in one of its western peaks, and covering the 
 gulf with night amid surrounding day." (Webb.) 
 
 38. GASSENDI. A noble crater 54 miles across, with a 
 group of conical mountains in the centre. It has two 
 small craters attached to its lower end. 
 
 For the more minute study of the above lunar objects 
 pretty high powers are advisable. The illumination 
 being ample, the highest powers of the telescope may be 
 profitably employed, if the atmospheric conditions are 
 favorable and the stand steady. But the most pleasing 
 views of the moon are those obtained with lower powers, 
 and it is surprising how much detail may be observed 
 with such powers, if the objective is a good one. I have 
 often seen the streaks extending from Messier, and the 
 Valley of the Alps, with a power of 48 on a 2^-inch glass. 
 
 One of the most interesting phenomena in connection 
 with the moon is the occultation by it of some star or 
 planet ; in other words, the passage of our satellite be- 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 65 
 
 tween a celestial object and some point on the earth's 
 surface. These occultations are extremely valuable, as a 
 little reflection will show, in the determination of terres- 
 ' trial longitudes, and are therefore predicted with great 
 care and accuracy in the Nautical Almanac. When a 
 fixed star is occulted by the moon's dark limb, the sud- 
 denness of its disappearance is simply startling. One 
 instant the star is shining in full brilliancy, the next it is 
 as if blotted out of existence. 
 
 The occultation of a planet is a not unfrequent occur- 
 rence, and is a spectacle of great beauty and interest, 
 although lacking the " dramatic suddenness " characteris- 
 tic of the occultation of a fixed star. 
 
 A singular phenomenon is sometimes witnessed when a 
 star is occulted by the bright limb of the moon. This is 
 the apparent projection of the star on the edge of the 
 moon itself. This strange appearance has heretofore only 
 been noted in the case of red or reddish stars, and is as 
 yet unexplained. It should be watched for, although it 
 is not very likely to be noted in a small telescope. 
 
CHAPTER VIII. 
 
 OBSERVATION, CONTINUED. THE PLANETS. 
 
 MERCURY. It is a matter of some little difficulty to the 
 observer whose telescope is without graduated circles, to 
 get a sight of this elusive little planet. A few days be- 
 fore and after its greatest eastern elongation from the 
 sun is the best time to see it. At its western elongation 
 it is, of course, equally easy to see, provided the observer 
 is willing to get up a sufficient time before sunrise, 
 which few amateurs are sufficiently- enthusiastic to do. 
 But what with low-hanging clouds and atmospheric va- 
 pors, the opportunities of seeing Mercury are rather rare ; 
 and moreover, owing to his nearness to the sun at the 
 best of times, he will not easily be detected during his 
 visibility, unless his place is known. 
 
 Mr. Proctor * gives an ingenious plan for finding this 
 planet. It consists essentially of calculating the time 
 when Mercury will appear at a given point, by taking the 
 difference between the right ascension of the sun and 
 that of the planet, and then noting the time at which the 
 sun crosses the given point. At a time after that, equal 
 to the difference of right ascensions, Mercury will cross 
 that point, allowance being made for the difference of 
 declinations. But by roughly estimating the position of 
 Mercury, and carefully "sweeping" about that point with 
 an opera or field glass, the planet can usually be picked 
 up without the employment of any troublesome devices. 
 
 * Half-hours, p. 77. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 67 
 
 The apparent diameter of Mercury at its inferior con- 
 junction is 12.9", and at its greatest elongation only 7". 
 To examine the planet with any satisfaction a high power 
 is required not less than 100 at the lowest. 
 
 VENUS. This splendid planet is one of the finest of 
 celestial objects, but at the same time one of the most 
 trying to the telescope. Its intense brilliancy brings out 
 every defect of the instrument, and sometimes the ob- 
 server is compelled to stop down his object-glass to obtain 
 a view of this planet free from u wings." Powers of from 
 80 to 200 may be employed. The apparent diameter of 
 Venus varies between 9.7" in superior and 66.5" in infe- 
 rior conjunction. 
 
 An hour at which the sun is still above the horizon is 
 the best time for observing Venus, as the illuminated sky 
 subdues the glare of the planet. By far the most striking 
 view which Venus ever presents in the telescope is that 
 obtained when she is in, or very near, her inferior con- 
 junction. She is then at her greatest apparent diameter ; 
 but all that the observer can see is a brilliant and beauti- 
 ful sickle of white light. Captain Noble recommends that 
 for this observation the diaphragm between the lenses of 
 the eyepiece be replaced by another of blackened card- 
 board, through the centre of which has been pierced a fine 
 hole with a red-hot needle. 
 
 MARS. For the satisfactory study of this most inter- 
 esting planet an object-glass of at least four inches is 
 required ; nevertheless, under favorable circumstances, 
 striking and beautiful views of Mars may be obtained 
 with quite small apertures. The only time, however, when 
 such telescopes will give such views is when the planet 
 is in or near opposition ; especially when the opposition 
 takes place under the peculiarly favorable circumstances 
 
68 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 presented, on the average, every fifteen years, when the 
 earth is furthest from the sun and Mars nearest to it. 
 Under such circumstances the apparent diameter of the 
 fiery planet is 30.4", which decreases to 4.1" at conjunc- 
 tion. The outlines of continents and seas may be de- 
 tected when Mars is at his greatest apparent diameter, 
 with a 2^/2. -inch glass with a power of from 150 to 200, 
 and the polar snow-caps may be seen with a power of 100 
 or even less. Even a 2-inch glass may do fairly good 
 work under favorable circumstances. High powers are 
 necessary to the study of this planet, and magnifying may 
 be pushed to the full extent of the telescope's capacity. 
 
 The phases of Mars may be seen with any power which 
 will exhibit a fairly good-sized disk. At quadrature it is 
 decidedly gibbous, resembling the moon at about three 
 days from full. 
 
 It is unnecessary almost absurdly so to state that the 
 satellites of Mars are utterly beyond the reach of a small 
 telescope. 
 
 THE MINOR PLANETS. A large number of these in- 
 teresting little bodies could be seen with a small tele- 
 scope, provided their places were known. Tables of the 
 elements of most of them may be found in Kirkwood's 
 Asteroids and in Loomis's Practical Astronomy. To cal- 
 culate the present position of any one of them, its longi- 
 tude at a given epoch is required. This is given in the 
 case of each planet by Loomis. But the sight of few of 
 these " pocket planets " will repay the amateur for the 
 laborious computations necessary to find them ; so that 
 the asteroids may be regarded, for all practical purposes, 
 as outside of our student's line of work. 
 
 Ceres, at the most favorable period, shines as a seventh- 
 magnitude star and at other times as an eighth. Its light 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 69 
 
 is reddish. Juno is very similar to it in size and color. 
 Pallas, the largest of all, appears, when in opposition, as 
 a star of the seventh magnitude, with a yellowish tinge. 
 Vesta is at times as bright as a white sixth-magnitude 
 star. 
 
 JUPITER. This gigantic orb is one of the standard 
 objects of study and admiration for the amateur telesco- 
 pist. Its changing belts, its circling satellites, and the 
 splendor of the entire system render Jupiter a source of 
 unfailing pleasure and wonder. 
 
 The apparent diameter of this planet varies from 50.7", 
 in opposition, to 30.8", in conjunction. Very little optical 
 aid, therefore, is required to exhibit its disk. A power 
 of fifty for every inch of aperture will exhibit the belts 
 excellently and the flattening of the planet at the poles. 
 Lower powers, however, must be used to see the entire 
 Jovian system at a glance, say a power of from forty to 
 fifty in a two-inch telescope, and even lower powers in a 
 larger one. 
 
 The student will be at once struck with the singular 
 and beautiful belts which stretch across the planet's disk. 
 In large telescopes these belts exhibit striking differ- 
 ences of color ; but in small ones they are usually of a 
 uniform dusky hue. They change in number and breadth 
 from time to time, sometimes exhibiting curious and 
 beautiful scalloped forms. One night's observations will 
 reveal, with sufficient powers, a difference in their general 
 aspect, owing to the swiftness with which this monster 
 globe revolves on its axis. 
 
 The most interesting phenomena in the Jovian system 
 are, of course, those connected with the satellites. These 
 bodies are distinguished by Roman numerals, in the order 
 of their distance from the primary. I., II., and IV 
 
70 THE AMATEUR TELESCOPIST*S HANDBOOK. 
 
 appear as stars of the seventh magnitude ; III. as one of 
 the sixth magnitude. Each night's observation will show 
 them in a different position with reference to their 
 primary ; and it is interesting to compare their observed 
 positions with the predicted ones as laid down for each 
 day in the Nautical Almanac. The tiny fifth satellite is, 
 of course, invisible in a small telescope. 
 
 The phenomena connected with the satellites are occul- 
 tations, eclipses, and transits. An occultation is the pas- 
 sage of a satellite behind the planet ; a transit is the 
 passage of a satellite across the face of the planet ; and 
 an eclipse is the entrance of a satellite into the shadow 
 of its primary. 
 
 Eclipses may be observed with small instruments and 
 low powers. Transits are much more difficult with such 
 means. The shadows of the satellites on Jupiter's disk 
 may be seen, under favorable circumstances, with a two- 
 inch glass, but to see the satellites themselves projected 
 on the disk requires a larger aperture not less than 
 three inches. The satellites appear on the disk as lumin- 
 ous points, preceded or followed by their shadows, which 
 exhibit themselves as round dark spots, not black, as the 
 visible shadows are largely composed of penumbra. The 
 shadow of IV. is nearly all penumbra, and even that of 
 I. is not wholly black.* The shadow of IV. is nearly 
 double the diameter of the satellite itself, and is larger 
 than that of III., although IV. is smaller than Ill.f The 
 shadow precedes the satellite when Jupiter is passing from 
 conjunction to opposition, but follows it when the planet 
 is between opposition and conjunction. 
 
 The occultations are the most difficult of the Jovian 
 
 * Proctor, Half-hours, pp. 86, 87. f Lassell. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 71 
 
 phenomena to small apertures ; but it may be added 
 that they are also the least interesting. All these phe- 
 nomena are duly predicted in the Nautical Almanac. 
 
 SATURN. Beyond all comparison this wonderful planet 
 is the most beautiful and striking object in the solar sys- 
 tem. Its retinue of satellites and its stupendous rings 
 make it by far the most gorgeously attended of all the 
 planets. Its satisfactory study is just beyond the powers 
 of a small telescope, an aperture of four inches being 
 required for a reasonably complete view. Enough may 
 be seen with a small instrument, however, to make Saturn 
 a source of unfailing wonder and admiration. The ap- 
 parent diameter of this planet varies from 14.6", in con- 
 junction, to 20.3", in opposition. 
 
 The belts of Saturn are much less conspicuous than 
 those of Jupiter, but a three-inch telescope, or even, at 
 times, a two-inch, will show them. The satellites will 
 prove very difficult objects to our observer, with the 
 exception of Titan and, under some circumstances, 
 Japetus. A two-inch glass will show these, if Japetus 
 is near its western elongation ; a three-inch may show 
 Rhea also ; a four-inch will add Tethys and Dione. 
 The others require large and powerful instruments. 
 Eclipses, etc., in the Saturnian system need not here be 
 dwelt upon, as they will be utterly beyond our observer's 
 telescope. 
 
 The ring may be seen readily with a two-inch tele- 
 scope. According to Mr. Proctor,* this aperture will 
 also show Ball's (Cassini's) division in the ring, but I 
 have never been able to detect this feature with any- 
 thing under three inches. Nothing below four inches will 
 
 * Half -hours, p. 92. 
 
72 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 show the curious and beautiful inner dusky or " crape " 
 ring. 
 
 The rings are known as A, B, and C, counting from 
 the outer ring. Ball's division forms the boundary 
 between A and B, but A is also marked by Encke's 
 division, which is much beyond the powers of a small 
 telescope. 
 
 A three-inch glass should show the difference between 
 the colors of rings A and B, the latter being decidedly 
 more silvery than the former and presenting a lovely con- 
 trast with the yellow ball of the planet. 
 
 High powers may be used upon Saturn with more satis- 
 faction than upon Jupiter, and the observer is advised to 
 try upon this glorious orb the highest powers that his tele- 
 scope will bear. He will find it worth his while to watch 
 and wait for atmospheric conditions sufficiently favorable 
 for this purpose. 
 
 URANUS AND NEPTUNE. Our amateur will be able to 
 see these planets as stars, and even, with sufficient power, 
 to raise them to disks. To find them with an altazimuth, 
 their right ascension and declination must be taken from 
 the Nautical Almanac, and their places carefully marked 
 on a map or planisphere. They may then be aligned from 
 neighboring stars. The apparent diameter of Uranus 
 never reaches four seconds, and a power of at least two 
 hundred is required to show it as a disk. Neptune will 
 hardly be distinguished from a dull eighth-magnitude 
 star except by the greater steadiness of its light and 
 the absence of diffraction rings around it. " What is 
 the lowest power," says Mr. Proctor, "which will ex- 
 hibit Neptune as a disk, I do not know ; but I am certain 
 no observer can mistake him for a fixed star with a two- 
 inch aperture and a few minutes' patient scrutiny in 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 73 
 
 favorable weather."* "The observer with a three-inch 
 telescope," says Captain Noble, " may be contented if he 
 can fairly satisfy himself that it is not a star that he is 
 looking at."f 
 
 * Half-hours, p. 92. \ Three-inch Telescope, p. 80. 
 
CHAPTER IX. 
 
 PRICES OF TELESCOPES AND THEIR ACCESSORIES. 
 
 FOR the convenience of intending purchasers of tele- 
 scopes, I deem it essential to the completeness of this 
 little handbook to give the names of certain well-known 
 and reliable opticians and manufacturers, together with 
 the prices asked by them for their instruments. I sub- 
 join extracts from the price-lists of three American and 
 two English artists and dealers, by the aid of which the 
 amateur may lay out the sum set apart for his astronomi- 
 cal recreations to the best advantage. The firms referred 
 to are the following : 
 
 ALVAN CLARK & SONS, CAMBRIDGEPORT, MASS. These 
 world-renowned artists are the makers of the great Lick 
 telescope of thirty-six inches aperture ; of the Pulkowa, 
 thirty-inch ; the Washington, twenty-six-inch ; the Univer- 
 sity of Virginia, twenty-six-inch ; and other famous and 
 magnificent instruments. They make for the use par- 
 ticularly of amateurs a series of comparatively small and 
 simply mounted refractors of low price and, of course, 
 distinguished excellence. 
 
 GEO. N. SAEGMULLER, late FAUTH & Co., WASHING- 
 TON, D. C. This eminent firm are the makers of the 
 twelve-inch equatorials of the Ladd Observatory, Provi- 
 dence, R. I., the Georgetown College Observatory, and 
 the new Naval Observatory at Washington ; and of the 
 nine-inch equatorial of the Catholic University in the 
 same city. 
 
THE AMATEUR TELESCOPIST*S HANDBOOK. 
 
 75 
 
 QUEEN & Co., PHILADELPHIA. This firm manufactures 
 and imports a cheaper but well-recommended class of 
 instruments. 
 
 J. COOKE & SONS, YORK, ENGLAND. These celebrated 
 artists are the makers of the noble twenty-five-inch New- 
 all refractor now at Cambridge, and other grand tele- 
 scopes. They rank among the great opticians of the 
 world. 
 
 HORNE, THORNTHWAITE & WOOD, 416 STRAND AND 
 74 CHEAPSIDE, LONDON. An old and well-known firm, 
 making a cheaper class of telescopes. 
 
 ACHROMATIC OBJECT-GLASSES, MOUNTED IN CELLS. 
 
 CLARK 
 
 
 
 
 
 
 3-inch. 
 
 Si-inch. 
 
 4-inch. 
 
 4|-inch. 
 
 5-inch. 
 
 6-inch. 
 
 $50.00 
 
 $75-00 
 
 $IOO.OO 
 
 $140.00 
 
 $200.00 
 
 $35- 00 
 
 SAEGMULLER 
 
 2-inch. 
 
 3-inch. 
 
 3^-inch. 
 
 4-inch. 
 
 4! inch. 
 
 5-inch. 
 
 $30.00 
 
 $6o.OO 
 
 $8o.OO 
 
 $IOO.OO 
 
 $140.00 
 
 $l8o.OO 
 
 
 
 5|-inch. 
 
 6-inch. 
 
 
 
 
 
 $250.00 
 
 $360.00 
 
 
 
 QUEEN 
 
 
 
 
 
 
 2^-inch. 
 
 2|-inch. 
 
 3 -inch. 
 
 Sl'inch. 
 
 4-inch. 
 
 4i-inch. 
 
 $15-00 
 
 $25.00 
 
 $30.00 
 
 $55-0 
 
 $80.00 
 
 $125.00 
 
 
 
 5-inch. 
 
 5l-inch. 
 
 
 
 
 
 $265.00 
 
 $350-00 
 
 
 
 COOKE 
 
 
 
 
 
 
 2-inch. 
 
 2^-inch. 
 
 2^-inch. 
 
 2|-inch. 
 
 3-inch. 
 
 3i-inch. 
 
 2 2S - 
 
 3 5 s - 
 
 4 *5 S 
 
 . 1 
 
 9 iw. 
 
 *4 
 
 
 4-inch. 
 
 4^-inch. 
 
 5 -inch. 
 
 6-inch. 
 
 
 34 48 
 
 HORNED THORNTHWAITE & WOOD 
 
 2^-inch. 3-inch. 3^-inch. 4^-inch. 5-inch. 
 
76 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 TELESCOPES, UNMOUNTED. 
 
 CLARK. Each telescope is provided with a finder, 
 diagonal eye-tube, front-surface reflecting solar prism, 
 one terrestrial eye-piece, and four celestial eye-pieces. 
 
 4-inch. 4|-inch. 5-inch. 6-inch. 
 $220.00 $270.00 $360.00 $550.00 
 
 The same without any accessories except four celestial 
 eye-pieces : 
 
 4-inch. 4^-inch. 5-inch. 6-inch. 
 $l6o.OO $2IO.OO $300.00 $490.00 
 
 SAEGMULLER. Telescopes of 3 inches and upward 
 have finders. The figures in parentheses refer to the 
 number of eye-pieces furnished with each instrument. 
 
 2|-inch(2). 3 -inch (3). 3|-inch (3). 4-inch (4). 4^-inch (4). 5-inch (5). 
 $90.00 $145.00 $165.00 $2IO.OO $265.00 $325.00 
 
 QUEEN. These instruments have blackened steel bodies 
 with brass mountings. Sizes below 4 inches are without 
 finders. The 3-inch telescope is provided with three 
 eye-pieces, all others with four. 
 
 3-inch. 3|-inch. 4-inch. 4^-inch. 5-inch. 6-inch. 
 $125.00 $175.00 $225.00 $300.00 $450.00 $600.00 
 
 COOKE. These telescopes have brass tubes, and all 
 over 2^ inches aperture are provided with finders, dew- 
 caps, and solar eye-pieces. Each has one terrestrial eye- 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 77 
 
 piece. The figures in parentheses refer to the number of 
 astronomical eye-pieces furnished with each instrument. 
 
 2i-in. (i). 2|-in. (2). 2f-in. (2). 3-in. (3). 3^-in. (4). 4-in. (4). 
 
 10 i$s. 14 iS los. 23 
 
 4i-m. (4). 5 -in. (5). 
 54 
 
 PORTABLE EQUATORIAL STANDS. 
 
 CLARK. Plain equatorial of best construction, without 
 circles, with tangent wheel for slow motion in right as- 
 cension, $110. 
 
 SAEGMULLER. Equatorial stand with tangent move- 
 ments, silvered circles reading respectively to 5 seconds 
 of R. A. and single minutes of declination, $150. 
 
 QUEEN. Small equatorial head, without stand, $18. 
 Universal Equatorial (i.e., one adaptable for any latitude), 
 of fine quality, without circles, fitted with tangent move- 
 ment, brass-mounted, $75 ; clamp for telescope, $6 extra ; 
 universal handle for R. A. wheel, $5 extra. A larger and 
 finer stand, with graduated adjustment for latitude ; 
 7-inch circles divided on solid silver, reading to 4 seconds 
 in R. A. and i' in declination ; circles read by verniers 
 and microscopes ; $250. 
 
 COOKE. Fine and heavy equatorial tripod-stand, uni- 
 versal adjustment, circles graduated on silver, with ver- 
 niers and reading microscopes ; tangent screw motions 
 in R. A. and declination brought down to eye-end, and 
 cross-levels. Made in three sizes. 
 
 Complete, for telescopes 5 to 5^ inches ... 
 
 4 to 4}^ " .... 50 
 " " 3 to 3^ " .... 4i 
 
78 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 With gun-metal circles instead of silver, the prices of 
 the above stands are ,62 ios., 47, and $& ios., re- 
 spectively ; and if the tangent-motion is not to be brought 
 down to the eye-end (a luxury which may be dispensed 
 with) deduct ^8, ^7, and 6 ios. from the foregoing 
 prices. 
 
 H., T. & W. Universal equatorial for telescopes up to 
 three and a half feet long, 6-inch brass circles reading 
 respectively to ios. in R. A. and 3' in Dec., ^15 i$s. 
 Same, without stand, for a 3 J^-inch telescope, with silver 
 circles and tangent movement, $o ; for 4^ -inch tele- 
 scope, 60. 
 
 TELESCOPES COMPLETE. 
 
 CLARK. Mounted on superior equatorial stand, with- 
 out circles, finished in first-class style, each telescope 
 provided with a finder, diagonal eye-tube, front-surface 
 reflecting solar prism, one terrestrial and four celestial 
 eye-pieces. 
 
 4-inch. 4^-inch. 5-inch. 6-inch. 
 $325.00 $380.00 $450.00 $650.00 
 
 SAEGMULLER. May be ascertained from foregoing 
 estimates. 
 
 QUEEN. May be ascertained from foregoing estimates. 
 
 COOKE. If equatorially mounted, the prices may be 
 estimated from data already given ; but if mounted on 
 altazimuth stand, the prices are as follows : 
 
 2^-inch, \6 i6s. ; 2>^-inch, ^20 ; 2^-inch, ^28, or 
 with tangent screws, $2 ; 3-inch, ^32, with t. s., 36 ; 
 3% -inch, ^39, with t. s., ^43 ios. ; 3^-inch, ^42 jos., 
 with t. s., ^47 ; 3^-inch, ^50 IQS., with t. s., ^55 ios. ; 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 79 
 
 4-inch, ^55 ios., with t. s., ^60 los. ; 4^-inch, 62 ios., 
 with t. s., ^67 105. ; 4^ -inch, ^"69, with t. s., ^76 IO.T. ; 
 5-inch, ^84, with t. s., ^94. 
 
 H., T. & W. These telescopes have brass bodies. Each 
 is provided with a finder and one terrestrial eye-piece 
 and is mounted on a brass pillar-and-claw stand. The 
 figures in parentheses refer to the number of celestial eye- 
 pieces furnished with each instrument. 
 3-in. (i). 3i-in. (2). 3^-in. (3). 3f-in. (4). 4-in. (5). 4Hn. ($). 
 i4s. iS iSs. 35 ^45 ^55 
 
 Mounted on equatorial stands with diagonal eye-tube, 
 solar eye-piece, circles, levels, etc. 
 
 3^-inch. 4-inch. 4^-inch. 5-inch. 
 
 ^80 ^95 
 
 With the last two instruments an iron pillar is fur- 
 nished, if desired, in lieu of the tripod, without extra 
 charge. 
 
 EYE-PIECES (HUYGENIAN). 
 
 SAEGMULLER. From J-inch to i-inch, $5.50. 
 
 QUEEN. From -J-inch to i-inch, $5.50. Munich 3-lens 
 eye-pieces, giving extra large field, i-inch, $6.00 ; J-inch 
 to --inch, $4.50. Adapter to fit draw-tube, $1.50. 
 
 COOKE. 195-. each. 
 
 H., T. & W. From 155. to^i 55. 
 
 ACCESSORIES. 
 
 First-surface reflecting prism for solar observations : 
 Saegmuller, $i ; Cooke,^i 5*.; H., T. & W., i 125. 
 
8o THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 CHEAPER TELESCOPES. 
 
 The cheapest of the above-described instruments will 
 doubtless be beyond the means of many a student to 
 whom the possession of a telescope is an object of ear- 
 nest desire. But they are all instruments of a high 
 class, some of them, indeed, of the most perfect quality 
 that art can produce. While such telescopes are of the 
 kind which the amateur should strive to secure, there are 
 others to be had of very fair quality and much lower 
 price. A three-inch telescope of French manufacture, 
 fitted with a terrestrial eye-piece magnifying fifty times, 
 and a celestial one magnifying one hundred times, is 
 commonly sold, unmounted, by city opticians for |6o, 
 and will do very fair service if provided with one or two 
 additional eye -pieces. A better instrument of the same 
 aperture, made by Bardou, of Paris, and mounted on a 
 pillar-and-claw stand, is sold for $120. 
 
 But should even the cheaper of these instruments be 
 beyond the means of the student, let him not despair. A 
 good second-hand "spy-glass" may often be purchased 
 for a small sum ; and if its aperture equal two inches, as 
 that of many ship-telescopes does, it may be mounted 
 after one of the methods described in Chapter II. and 
 provided with either astronomical eye-pieces, or, what 
 serves just as well for small apertures, with microscopic 
 eye-pieces. These are of the Huygenian form, and cost 
 less than the others. Such eye-pieces, of the best quality, 
 may be obtained from the Bausch and Lomb Optical Co., 
 of Rochester, N. Y., for $3 each. 
 
 Such a telescope was used by the author for many 
 years ; and if the objective is at all good, quite a large 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 8l 
 
 proportion of the objects described in this book will be 
 found to be within the range of its powers. 
 
 The catalogues and circulars of the following artists 
 and manufacturers may also be consulted with profit : 
 
 John Byrne, with Gall & Lembke, 21 Union Square, 
 New York ; a maker of objectives, etc., of the highest 
 class. 
 
 J. A. Brashear, Allegheny, Pa. Highest-grade objec- 
 tives, etc. 
 
 Warner & Swasey, Cleveland, Ohio. Equatorial mount- 
 ings of the finest character. 
 
 - W. & D. Mogey, Bayonne, N. J. Small equatorial 
 mountings. 
 
 THE GREEK ALPHABET. 
 
 a Alpha. z Iota. 
 
 Beta. K Kappa. 
 
 y Gamma. A Lambda. 
 
 d Delta. p. Mu. 
 
 Epsilon. v Nu. 
 
 2 Zeta. % Xi. 
 
 77 Eta. o Omicron. 
 
 6 Theta. n Pi. 
 
 p Rho. 
 a Sigma. 
 r Tau. 
 v Upsilon. 
 cp Phi. 
 X Chi. 
 $ Psi. 
 co Omega. 
 
(JMesttal 
 
 In the following catalogue the positions of objects are 
 given for the year 1890, except in a few cases where the 
 positions are for 1880, and are stated to be so. I have 
 not considered it necessary to bring these latter positions 
 up to date, as they are sufficiently accurate for finding 
 purposes. 
 
 Position angles are omitted, as they serve no purpose 
 for the amateur telescopist. 
 
 All quotations not otherwise credited are from Admiral 
 Smyth's Cycle of Celestial Objects, which is the principal 
 source from which these lists have been compiled. 
 
 Greek letters not followed by the name of a constellation 
 refer to stars in the constellation then under description. 
 
 The following abbreviations are employed in this cata- 
 logue : 
 
 R. A., Right Ascension. 
 
 Dec., Declination ; +, North ; , South. 
 
 D., Distance. 
 
 1$, Sir William Herschel. The Roman numerals fol- 
 lowing this sign refer to the number of that catalogue of 
 nebulae containing the object under description. 
 
 H., Sir John Herschel's General Catalogue of Nebulae, 
 1864. 
 
 M., Messier's Catalogue of 103 Nebulae, 1783-84. 
 
 P., Piazzi's Palermo Catalogue, 1814. The Roman 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 numerals following this initial refer to that one of the 
 XXIV. hours of R. A. into which this catalogue is di- 
 vided, which contains the object under description. 
 
 h., Sir John Herschel's First Catalogue of Nebulae, 1833. 
 
 h.*, Sir John Herschel's General Catalogue (so-called) 
 of Double Stars. 
 
 B., Bode's Catalogue. 
 
 Lai., Lalande's Catalogue. 
 
 2, Wilhelm Struve's great Dorpat Catalogue of Double 
 Stars. 
 
 B. A. C., British Association's Catalogue. 
 
 Birm., Birmingham's Catalogue of Red Stars, 1877. 
 
 Dunlop, His Catalogue of 
 Southern Clusters and Nebulae. 
 
 A telescopic field is divided 
 into four imaginary quadrants, 
 which are designated respect- 
 ively south preceding, south fol- 
 lowing, north preceding, and 
 north following ; usually ex- 
 pressed by the initials sp, sf, 
 etc. They are placed as in the 
 diagram. 
 
 The number of stars in each constellation is given 
 according to Bode's estimate. 
 
 ALIGNMENT STARS. 
 
 The position, with reference to conspicuous stars, of 
 many of the objects used in the following pages for the 
 " alignment," to use Admiral Smyth's convenient word, of 
 inconspicuous celestial bodies, is already given in the 
 Catalogue itself ; but I append directions for quickly and 
 
84 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 easily finding all the stars used for alignment in these 
 lists in order to save the student from having to distract 
 his attention and unfit his eyes for immediate use at the 
 telescope by poring over a map by lantern light. 
 
 While it is by no means necessary, the observer will 
 greatly facilitate his work, increase his knowledge of the 
 heavens, and keep his eyes in good condition for the tele- 
 scope by memorizing the positions of all these guiding 
 stars a task which will be found far less formidable 
 than it sounds. 
 
 A knowledge of all first-magnitude stars, of Polaris, and 
 of the general positions of the constellations is assumed. 
 
 ANDROMEDA. Draw a line from Polaris through the 
 brighter of the two stars forming the seat of Cassiopeia's 
 Chair, and extend it 25. It will reach a point 3 W. of 
 a second-mag, star, which is ft. S.W. of /?, and y-J from 
 it, is a third-mag., which is 6, and the same distance from 
 d, W. and a little S., is a second-mag., which is a. 3-^ 
 N.W. of /?, and forming with it a curved line, are two 
 fourth-mag, stars, the lower of which is //, the other v. 
 
 AQUARIUS. Draw a line due N. from Fomalhaut 14. 
 It will pass very near 6, of mag. three, the brightest star 
 in that neighborhood. Draw a line from Fomalhaut 
 through d, and 16 on. 3^ W. of the point thus reached 
 are three stars forming a nearly straight line 7 long, due 
 E. and W. They are, in that order, 77 (4), (3), and a (3). 
 Just S. of the middle of the line is y (3). 10 S.W. of a 
 is ft (3). A line from Fomalhaut to tf, and 8J on, reaches 
 A (4), and 6 E., about 2 S., is a little group of three stars, 
 of which the fourth-mag, one is ^. 8 exactly S.W. of 
 ft is v (4). 
 
 AQUILA. a is almost midway between y (3) and/? (4), 
 the three stars forming a line nearly 5 long with ft at the 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 85 
 
 S. end. This line points to 6 (3), 8| S. Just east of 
 the line between a and /?, i from #, is (5). 4^ W. of 
 a, nearly at right angles with the above line, is ju (5). A 
 line from to j3 and 4^ on passes about i E. of ?;. 
 Draw a line from Polaris through Lyra, and at a point 
 1 2^ N.W. of Altair it will strike a third-mag, star, which 
 is % (3). i8| due S. of is A. (3). 2 N.W. of % is * (4). 
 
 ARIES. This constellation contains but two stars of 
 mag. three, a is 24 due W. of the Pleiades, and /3 4 
 S.W. of a. y (4) i s J i S. of ft. s (4) is I2-J- from a, on 
 line to Aldebaran. 
 
 AURIGA. ft (2) is 7^ E. of a. 9 due N. of ft is d 
 (4). 5-j- S. and somewhat W. from #, are two fourth- 
 mag, stars about i apart. The one to the E. is 77, the 
 other . 
 
 BOOTES. The first bright star N.E. of a is e, 10 dis- 
 tant, and 8 further on in the same line is d (3). ft (3) 
 is 8 N., a little W. from tf. 
 
 CANCER. Draw a line from Regulus to Procyon. It 
 will pass, at a distance of 17^ from the former something 
 less than half way 3 S. of a fourth-mag, star, which is a. 
 6| N. and 3^ W. of a is a fourth-mag., which is 6. 11 
 due N. of 6 is i (4). 
 
 CANES VENATICI. A line from Polaris through the 
 northernmost of the three stars forming the handle of the 
 "Dipper," and 17^ on, will reach a, a bright third-mag, 
 star. 
 
 CANIS MAJOR. The conspicuous third mag. 5f W. 
 and somewhat S. of Sirius is ft. S. and W. of a are four 
 third-mag, stars forming, as it were, three arms of a cross. 
 The central one is 6, the furthest W. is e, the furthest E., 
 77. A line from r) to e and 9 on reaches a point i-J S. 
 o f $ (3). 5 N. and 2 W. of a is 6 (4). 
 
86 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 CANIS MINOR. fi is the third-mag, star 4^ N.W. 
 of a. 
 
 CAPRICORNUS. Draw a line from Fomalhaut through 
 e Pise. Aust., the fourth-mag, star, 5^ N.W. of it, and 17! 
 on. It will reach a fourth-mag, star, the easternmost of 
 three such stars, which form a straight line from E. to 
 W. 8| long. They are, in that order, y, i, and 6. /3 is 
 the third-mag, star about i-J E., a little N. of y. The 
 fourth-mag, star 5^ S., a little E. from z, is . A line 
 from i to 6 and 11 on will reach a point 3^ S. of a third- 
 mag, star, which is /?, and 2^ N. of ft is a. 
 
 CASSIOPEIA. The well-known " Chair " is composed as 
 follows : Dividing its six stars into feet, seat, and back, 
 we find that the feet are a (South) and /3 (North) ; the 
 seat, y (S.) and n (N.) ; the back, 6 (S.) and e (N.). 
 and are two fourth-mag, stars, which form a scalene 
 triangle with a; 8 being 4 S.E. of a, and 2 3 S. 
 of a. 
 
 CEPHEUS. This constellation is marked by an irregular 
 square of four third-magnitude stars, the longest diagonal 
 of which square is about 12. On the W. side of the 
 square the star nearest the pole is ft, the other a. On 
 the E. side the star nearest the pole is z, the other . 
 1 1| N.E. of ft is y (3). 2i due E. of 2 is d (4). 4 W., 
 a trifle S. from a, is rj (4). 
 
 CETUS. 26 S.W. of Aldebaran is a (3). 5 W., a 
 little S. from a, is y (3). 8^ exactly S.W. from y is o. 
 A line from y to o, and 10 on, reaches (3). io-j- due 
 W. from 8, is 77 (3). 2 N. of a line from 2 to 77 is 6 (3). 
 10 S.W. of rf is ytf (3). IT N.W. of is z (3). The 
 alignments here sound difficult, but they are in reality 
 very easy, as the constellation contains so few conspicu- 
 ous stars. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 87 
 
 CORONA BOREALIS. 18 due W. and 7^ N. from 
 Arcturus 20 from it is a second-mag, star, which is a. 
 Two fourth-mag, stars lie just E. of it, forming with it a 
 line 3| long. The nearest to a is y, the other 6. 
 
 CORVUS. A line drawn S.W. from Spica 17} will 
 reach the centre of the square of third-mag, stars mark- 
 ing Corvus. The western stars of the square are y (N.) 
 and s (S.) ; the eastern, d (N.) and ft (S.). 
 
 CRATER. This asterism adjoins Corvus on the W. It 
 contains one third-mag, star, which is d ; 6 S.W. of d is 
 
 ( 4 ). 
 
 CYGNUS. The cross in this constellation is made up as 
 follows : In the centre is y ; furthest N., a ; furthest 
 S., ft. In the cross-piece : furthest E., ; furthest W., 6. 
 6 S.E. of s is Z (3). 5 N. of Z, is v (4). About 
 8 N., somewhat W. of d, are two fourth-mag, stars nearly 
 3 apart. The nearest to d is z, the other H. A line 
 from 8, to v, and iij on, will reach p (4). 
 
 DRACO. Draw a line from Polaris to Wega; 22^ from 
 the former the line will pass 3 W. of a third-mag, star, 
 which is d. 17^ S.W. of 6 will be seen a trapezium com- 
 posed of two third-mag., one fourth-mag., and one second- 
 mag, stars. The eastern of these are (N.) and y (S.) ; 
 the western, v (N.) and /3 (S.). y and v point to a third- 
 mag, star nj N.W., which is rj. 
 
 ERIDANUS. 1 W., a little S. from Rigel, is a fourth- 
 mag, star, which is A. 3|- almost due N. of A is ft (3). A 
 line from the middle of Orion's belt through /?, and 19 on, 
 reaches y (3). The two third-mag, stars N.W. of y are 
 d (E.) and f (W.); and 9 nearly due W. of e is 77. 
 
 GEMINI. 8 S.W. of Pollux is d (3). 12 from <S on 
 line to Betelgeuse is y (3). 7^ N.W. of y will be seen 
 two third-mag, stars, which are // (E.) and r\ (W.). 4 
 
88 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 S.E. of y is (4). 12 due N. of is (3). 4 W., a 
 little S. from <?, is 3 (4). 
 
 HERCULES. A line from Wega drawn W. and a little 
 S. 20 will reach the centre of a large trapezium of four 
 third-mag, stars. Of these the eastern members are 
 n (N.) and e (S.) ; the western, ? ? (N.) and < (S.). nj 
 due S. of TT is tf (3), and the same distance due S. of $ 
 is a. n and f, and also 77 and , point to a spot 2 E. of 
 ft (2). 3 S.W. of/isy( 3 ). 
 
 HYDRA. About 13 E., a trifle N. from Procyon, are 
 two third-mag, stars 2j apart. They are 8, (E.) and 
 s (W.). 17 S.E. of these is a (2). On the W. border of 
 Crater is a third-mag, star, which is v, and 5^ nearly due 
 E. of v is yw (4). 7 is the fourth-mag, star, 12 S., a trifle 
 W. from Spica. 
 
 LEPUS. This asterism is S. of Orion. It contains only 
 two third-mag, stars, which are a (N.) and ft (S.). 
 
 LEO. The six stars forming the Sickle, counting from 
 Regulus, are a, 77, y, , ju, and e. /3 (2) is 25 E., a little 
 N. from ex. is a fifth-mag, star 9 nearly due W. of a. 
 
 LIBRA. A line drawn 27 due E. from Spica reaches a 
 point 2 S. of a third-mag, star, which is ft. 91 exactly 
 S.W. from ft is a (3). 
 
 LYRA. S. and somewhat E. from a about 6| are two 
 third-mag, stars 2 apart. They are y (E.) and ft (W.). 
 7 due E. of a are two fourth-mag, stars less than 2 apart. 
 They are 77 (N.) and (S.). 
 
 OPHIUCUS. 16 N., a trifle E. from Antares, is (3) ; 
 and N.E. of Antares about 14 is 77 (3). 9^ S. and 2^- 
 E. from 77 is (4). is the second-mag, star furthest N. 
 in the constellation. 8^ S., a little E. from a, is ft (3). 
 x (3) * s 9J- E- an d considerably S. from #, forming with 
 it and ft a scalene triangle, y (4) is 2 S.E. from /?. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 89 
 
 ORION. y (2) is at the N.W. corner of the great 
 quadrilateral, and n (3) at the S.E. The stars in the 
 belt, from W. to E., are 6, e, and . The fourth-mag. 
 3 from tf, almost on the line to Rigel, is 77 ; and the 
 northernmost of the three stars in the head is A. 
 
 PEGASUS. A line from Altair E., a trifle N., 28 will 
 reach a second-mag, star, which is e. 7 S.E. of is 
 (3)- 9i N - E - of (9 is ^ (3). 7 N.E. of 2 is a (2). 
 13 due N. of a is ft (2). 17 due E. of a is y (3). 
 
 PERSEUS. a (2) is the brightest star in this constella- 
 tion, and is 20 E. and somewhat N. from Capella. It 
 lies nearly midway between two third- mag. stars, forming 
 with them a curved line about 8 long. They are y (N.) 
 and d (S.). 12^ nearly due S. of y is ft. 9 nearly due 
 E. of ft is s (3). 8 nearly due S. of e is 2 (3). 3^ due 
 N. of ft is H (4). 
 
 PISCES. a can only be aligned from a neighboring 
 constellation. It is a third-mag, star 10 nearly due W. 
 of y Ceti. 
 
 SAGITTA. A line from Wega through y Lyrae and 
 i7j on reaches two fourth-mag, stars about i apart. 
 They are a (N.) and ft (S.). 
 
 SAGITTARIUS. 23 J E. and 4 S. from Antares is a third- 
 mag, star, which is y. 3} E. of y, a trifle N., is d (3). 
 5 N.E. of d is A (3). 6| E., a little S. of A, is a. 6J 
 N.E. of a is n (3). 4 S. and 2 E. of is Z (3). 6 
 N.W. of A is fjL (4). 
 
 SCORPIO. 2j N.W. of Antares is a (3), and 6 further, 
 in the same line, is d (3). ft (2) is 3 N.E. of d. 21 
 W., a little N. from Antares, is y (3). 
 
 SERPENS. 22 N. and a little W. from Antares will be 
 found two third-mag, stars ij apart, which belong to 
 Ophiucus. 12 N.W. from these will be found a similar 
 
90 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 but wider pair. These are a (2) and 8 (3). 8 due S. of 
 s is )A (3). i N.E. of a is A (4). 9 nearly due N. of 
 a is ft (3). 9j S. and 2J W. from Aquilae is (4), 
 and 11 S.W. of (9 is 77 (4). 
 
 TAURUS. nj due N. of the group in Orion's head is 
 Z (3). 8 N. and 3 W. of is ft (2). 7 N., a little E. 
 from a, is r (4). 
 
 TRIANGULUM. 7^ S., a little E. from y Andromedae, 
 is/? (3). 7*S.W.of/?is(4). 
 
 URSA MAJOR. The stars in the " Dipper," from the 
 Pointer nearest the Pole, are <*, /?, y, 6, f, , and 77. A line 
 from tf to /? and about 20 on will pass near two third-mag, 
 stars ii apart. These are z (N.) and (S.). 6 N.E. of 
 them is (3). About 12 S.E. of 6 is another pair of 
 third-mag, stars, which are A (N.) and /* (S.). A line from 
 Polaris through the " Dipper " bowl and about 22 on will 
 reach a third pair of stars, mags. 3 and 4, of which the 
 northern one is v. 
 
 VIRGO. 6 N.W. from Spica is (4). 8 N.W. from 
 6 is y (3). 5i W. of y is 7; (3). * 7^ W. and somewhat 
 N. from 77 is ft (3). 6 N.E. of y is d (3), and 8 N., a 
 little E. from d, is e (3). 
 
 A DESCRIPTIVE CATALOGUE OF FOUR HUN- 
 DRED AND SIXTY-EIGHT CELESTIAL 
 OBJECTS. 
 
 ANDROMEDA. 
 
 An extensive northern constellation. Mean R. A., i2h. 
 5om. ; Dec., + 26 ; stars, 226. 
 
 a. (Alpheratz.) R. A., oh. 2m. 415.; Dec., + 28 29.2'. 
 A difficult double. A 2, white; B n, purplish. D., 70.2". 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. QI 
 
 /?. (Merach.) R. A., ih. 301. 345.; Dec., + 35 2.3'. A 
 bright star, with distant companion. A 2, fine yellow ; B 
 10, pale blue. D., 304". 
 
 y. (Almaack.) R. A., ih. 57m. 8s.; Dec., + 4 48.1'. 
 A splendid double ; really triple, but not in a small tele- 
 scope. A 3^, orange ; B 5^, emerald green. D., 10.1". 
 
 6. R. A., oh. 33m. 265.; Dec., + 30 15.5'. A bright 
 star, with a difficult distant companion. A 3, orange ; B 
 10, dusky. D., 229.1". 
 
 n. R. A., oh. 31 m. os.; Dec., + 33 6.8'. A fine double. 
 A 4^, fine white ; B 9, blue. D., 35.1". Line from a Pegasi 
 to a Andromedae and 8 beyond, a trifle to the N. 
 
 4 Birm. R. A., oh. i4m. 55.; Dec., + 44 5.9'. A fine 
 red eighth-mag, star. Line from a Cassiopeae to Cass. 
 and 10 on. 
 
 56. R. A., ih. 49m. 375.; Dec., + 36 42.2'. A neat 
 double. Both 6, both yellow. D., 181.6". Probably a 
 binary. 6 from y on line to a Trianguli. 
 
 240 P. XXIII. R. A.,23h. 5 2m. 285.; Dec., + 23 44.3'. 
 . fine double. A 8|, pale white ; B 9, yellowish. D., 9.1". 
 Knott, in 1862, pronounced B "most decidedly blue." 
 Line from the ^word-handle of Perseus through a and 
 5 on. 
 
 R. R. A. (1880), oh. 1 8m.; Dec., + 37 55'. A rich 
 orange star, which varies in 405 days from about mag. 6 
 to invisibility. About 10 from a on line to B Cass. 
 
 31 M. (H., 116.) R. A., oh. 36m. 473.; Dec., +40 40.1'. 
 The Great Nebula in Andromeda, justly described by 
 Smyth as " overpowering." Under favorable circum- 
 stances it can be seen by the naked eye as a faint cloudy 
 spot. In shape it is somewhat oval, with considerably 
 greater brilliancy at the centre than at the edges. Its 
 light probably requires about 6,000 years to reach us. It 
 
92 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 has never been resolved, but, according to Huggins, is 
 not gaseous. Its spectrum, however, is suddenly cut off 
 at the red end a most mysterious and inexplicable cir- 
 cumstance. 
 
 This nebula has a small nebula (32 M.), 25' S. of it, of 
 much feebler light. The major axis of the Great Nebula 
 is about 40' in length, and the minor axis about 15'. i^ 
 due W. of v. 
 
 32 JL VII. (H., 457.) R.A., ih.5im. 145.; Dec., + 37 
 7.6'. A large, rich cluster, about 30' in diameter. Line 
 from a to ft and 8 on. 
 
 ANSER ET VULPECULA (THE GOOSE AND Fox). 
 
 A modern constellation constructed by Hevelius. Mean 
 R. A., 2oh.; Dec., + 25 ; stars, 126. 
 
 6 and 8. R. A., 19!!. 2401. 8s. ; Dec., -f 24 26.6'. A pair of 
 stars. A 4, deep yellow ; B 5, yellowish. D., 403.5". Line 
 from Altair through a and (3 Sagittae and 7j on. 
 
 2504 2. R. A., i9h. i6m. 95.; Dec., + 18 56.4'. An in- 
 teresting double. A 6-J-, yellowish white ; B 8^, bluish. D., 
 8.9". Duner found these stars sometimes white, some- 
 times yellow. Line from Wega midway between ft Lyr. 
 and y Lyr. and 16 on. 
 
 320 P. XIX. R. A., i9h. 48m. 315.; Dec., + 20 3'. A 
 wide double. Both 7, both white. D., 42.3". Line from 
 Wega to ft Cygni and 9 on. 
 
 2769.2*. R. A., 2 ih. 5m. 355.; Dec., + 22 0.4'. A pretty 
 double. A 7, B 8, both white. D., 18.2". Line from a 
 Cephei through Cygni and 8 on. 
 
 R. R. A. (1880), 2oh. 59m.; Dec., + 23 21'. Aredstar, 
 variable in about 140 days from mag. 8 to invisibility with 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 93 
 
 the most powerful telescope. 2 from last object on line 
 to y Lyrse. 
 
 21 ] VIII. (H., 4497.) R. A., i 9 h. 22m. 345.; Dec., 
 + 24 55.1'. A large straggling cluster, whose brightest 
 members assume the form of a Greek 1. 3 from ft 
 Cyg. on line to Attair. 
 
 27 M. (H.,4532.) R. A., igh. 54m. 485.; Dec., + 22 25'. 
 The singular " Dumb-bell " Nebula. This extraordinary 
 binuclear nebula has, in a small telescope, an oval shape, 
 but it bears magnifying well, and with a good 2^-inch 
 glass the duplicity of the nucleus may be seen. It is 14 
 from Altair on line to a Cephei. 
 
 ANTINOUS. 
 
 A constellation frequently joined with Aquila. Mean 
 R. A., i9h. 35m.; Dec., 3 ; stars (with Aquila), 276. 
 
 274 P. XVIII. R. A., i8h. 57m. 55.; Dec., o5i.9'. A 
 double star ; triple in large instruments. Both 9, both 
 white. D., 23.8". 4 from A, a trifle E. of a line from A 
 to 6 Serpentis. 
 
 2654 2. R. A., 2oh. 9m. 245.; Dec., 3 50.4'. A beau- 
 tiful double. A 6|, B 8. Both white, according to 
 Smyth, but according to Webb, yellow and blue. D., 1 1.8". 
 Line from Altair through 6 Aquilae and 2 J on. 
 
 140 P. XX. R. A., 2oh. 2im. 465.; Dec., 2 28.3'. A 
 wide double in a very fine field. A 71, B 8, both white. 
 D., 59.6". Line from e Pegasi to 6 Aquilae and 3 on. 
 
 ii M. (H.,4437.) R. A., i8h. 45111. 135.; Dec., - 6 
 24.1'. A splendid cluster, nebulous in a small telescope. 
 Smyth likens it in shape to a flight of wild ducks. 3f 
 from A on line to rj Ophiuci. 
 
94 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 AQUARIUS (THE WATER-BEARER). 
 
 A not very conspicuous constellation, containing no stars 
 above the third magnitude, but astronomically important 
 owing to its position in the Zodiac and its telescopic 
 richness. Mean R. A., 2ih. 5001. ; Dec., 10 ; stars, 343. 
 
 r 2 . R. A., 22h. 43m. 473.; Dec., 14 10.3'. A 
 beautiful orange-red star, with a distant bluish companion 
 of mag. 9. The primary is of mag. 5 a lovely object. 
 D-> I 33-4"- 2 f f rom # on line to y. 
 
 ^}\ R.A., 23h. rom. 75.; Dec., 9 41.3'. Abeautiful 
 double. A 5^, orange tint ; B 9, sky blue. D., 49.9". 
 y Capricorni and 6 Capr. point to this object, 22^ from 
 the latter. 
 
 R. R. A. (1880), 23h. 3 8m.; Dec., 15 57'. A deep- 
 red star, variable in about 390 days from mag. 6 to 12^. 
 Line from $ Capr. to d Aquarii and 12^ on. 
 
 29. R. A., 2ih. 56m. 255.; Dec., 17 29.7'. A 
 beautiful close double. Both 7, both white. D., 3.6". 
 Line from i Capr. to y Capr. and 5^ on. 
 
 41. R. A., 22h. 8m. 145.; Dec., 21 37.3'. An ele- 
 gant double. A 6, topaz yellow ; B 8-J, cerulean blue. D., 
 5.1". 8 from d Capr. on line to Fomalhaut. 
 
 53. R. A., 22h. 2om. 345.; Dec., 17 18'. Abeau- 
 tiful double. Both 6, both pale white. D., 7.8". Line 
 from i Capricorni to y Capr. and n-J on. 
 
 94. R. A., 23h. i3m. i8s.; Dec., 14 3.4'. A lovely 
 double. A 6, pale rose tint ; B 8-J, light emerald. D., 
 13.8". 6^ from d on line to i Ceti. 
 
 107. R. A., 23h. 4om. i8s. ; Dec., 19 17.5'. A very 
 beautiful double. A 6, bright white ; B 7^, blue. D., 
 5.8". Line from y to A and 17 on. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 95 
 
 2913 2. R. A., 22h. 24m. 455.; Dec., 8 40.7'. A 
 pretty double. A y|, white ; B 8-J, reddish. D., 7.9". 
 7-J from y on line to Fomalhaut. 
 
 219 P. XXII. R. A., 22h. 42m. ios.; Dec., 4 47.8'. 
 A triple star. A 7^, yellow ; B 8, C 9, both flushed 
 white. D., AB 3.8", AC 48.6". 6 from 2 on line to ip. 
 
 1 ip IV. (H., 4628.) R. A., 20 h. 58m. ios.; Dec., - 
 11 47.7'. A planetary nebula of a pale-blue color, bright 
 to its edges and about 20" in diameter. " One of the 
 finest specimens of these extraordinary bodies." (Webb.) 
 Owing to its appearance in his telescope, Lord Rosse 
 called this the Saturn nebula, and Lassell saw it as an 
 elliptical ring with a star in the centre. It yielded to 
 Dr. Huggins a gaseous spectrum. According to Sir 
 John Herschel, if this object be only as far distant from 
 us as the stars and its distance is probably enormously 
 greater its dimensions must be such as would fill the 
 whole orbit of Uranus. A globular body of such size 
 could contain more than sixty-eight thousand millions 
 of globes as large as our sun. i due W. of v. 
 
 2 M. (H., 4678.) R. A., 2 ih. 27m. 445.; Dec., - i 
 19. i'. A fine globular cluster, nebulous in all but large tele- 
 scopes. The total light yielded by it does not exceed 
 that of a star of the sixth magnitude. In the Herschel 
 telescope it resembled a heap of fine sand. Huggins finds 
 it gaseous. Diameter, 5' or 6'. Line from 2, Capricorn! 
 to ft Aquarii and 5 beyond. 
 
 AQUILA (THE EAGLE). 
 
 A rich and beautiful constellation, lying directly in the 
 Milky Way. It is frequently joined with Antinoiis as one 
 
96 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 asterism. Mean R. A., i6h. 2om. ; Dec., + 10 ; stars 
 (with Antinoiis), 276. 
 
 a. (Altair.) R, A., i 9 h. 4501. 248.; Dec., + 8 34.2'. 
 A brilliant star with a distant companion. A i^, pale 
 yellow; B 10, violet tint. D., 156.1". Will be found 
 very difficult in a small telescope. 
 
 ft. (Alshain.) R. A., iph. 49m. 545.; Dec., + 6 8.3'. 
 A star with several small companions. Mag., 3^. The 
 principal companion is of mag. 10, pale gray, and presents 
 a singular contrast to the delicate orange of the primary. 
 D., 151.7". Difficult. 
 
 R. R. A. (1880), 19!!. im.; Dec., + 8.3 ; . Adeep-red 
 star, varying in 345 days from mag. 6.5 to n. (Arge- 
 lander.) 5! from on line to A. 
 
 T. R. A., i8h. 4om. 265.; Dec., + 8 38.1'. A pale 
 ruby star, varying in about four months from mag. 9 
 to 9^. 7 from e on line to rj Serpentis. 
 
 15. R. A., i8h. 59m. 95.; Dec., 4 11.7'. A fine 
 double. A 6, yellowish; B 7^, lilac. D., 37.1". Other 
 stars in field. i N., a little W. of A. 
 
 57. R, A., 190. 48m. 405.; Dec., 8 30.8'. A fine 
 double. A 6^, B 7, both blue according to Smyth, but 
 observers differ to a remarkable extent as to these colors, 
 and Webb urges telescopists to watch this pair. D., 35.6". 
 Line from a to rj and 9^ on. 
 
 483 Birm. R. A., i8h. 5501. 325.; Dec., 5 50.9'. A 
 very deep-red star of mag. 7^. " A fine specimen of a re- 
 markable and beautiful class." (Webb.) if S.W. of A. 
 
 302 P. XVIII. R. A., i9h. om. 255.; Dec., + 6 23'. 
 A very neat double. A 7^, lucid white ; B 9, cerulean 
 blue. D., 9.9". Line from rj to 6 Serpentis and 4 on. 
 
 241 P. XIX. R. A., i 9 h. 37m. 265.; Dec., + 8 7.3'. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 97 
 
 A delicate double. A 7^, pale topaz ; B 9^, lilac. D., 
 26.7'. It is 4 E. and a little S. from a, and just above 
 /*, a fifth-mag, star. 
 
 43 P. XX. R. A., 2oh. 8m. 465.; Dec., + 6 14.8'. A 
 double star. A 6.8, B 7.2, both lucid white. Line from 
 a to , the fifth-mag, star, i S.E. of it and 5 on. 
 
 47 ^L I. (H., 4441.) R. A., i8h. 4 7m. 75.; Dec., - 8 
 50.1'. A globular cluster 6' in diameter. The component 
 stars are small, and the cluster is less bright toward the 
 centre. A line from 6 through A and 4f further on will 
 reach a point 40' S.E. of this cluster. 
 
 1913 VII. (H. 4470.) R. A., i9h. 2m. 195. ; Dec., + 4 
 3.4.' A large and rich cluster of stars from mag. 12 to 
 14. A line from d Aquilae to 6 Serpentis will pass about 
 i S. of it, 4j from the former star. Difficult. 
 
 2035 h. (11.4482.) R. A., i ph. i im. us.; Dec., 1*6.9'. 
 A loose, splashy cluster of stars from mag. 9 to 1 2. Rather 
 difficult in a small telescope. 4^ from d on line toward A. 
 
 4473 H. R. A., i9h. 5m. 525. ; Dec., + o 51'. A re- 
 markable faint nebula, which, according to Hind, is vari- 
 able. It is 21 N. E. of the last object, on a line toward 
 6 Serpentis. 
 
 ARGO NAVIS (THE SHIP ARGO). 
 
 A grand constellation, most of which is below the hori- 
 zon in every part of the United States, much more in 
 England. Mean R. A., 9h. ; Dec., 55. Stars, 540 ac- 
 cording to Bode, and 1,330 according to Sir T. Brisbane. 
 
 149 P. VII. R. A., 7h. 29m. 405. ; Dec., 23 14.1'. A 
 splendid double. Both mag. 6, both topaz. D., 9." Line 
 from Pollux to Procyon and 28 beyond, or from Orion's 
 sword through Sirius and 14 on. 
 
 7 
 
98 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 1138 2. R. A., yh. 4001. 263. ; Dec., 14 25.4'. A 
 double star. A 7, silvery white ; B 7^, pale white. Line 
 from a Leporis through Sirius and as far again to the E. 
 Almost in the field is 4 Argo Navis, a yellow 5th mag. star. 
 
 15219 Lalande. R. A., 7h. 42m. 455. ; Dec., 15 44.5'. 
 A fine pair of stars. Both mag. 6J, both deep orange. 
 D., 127.8". A line from /? Canis Majoris carried i S. 
 of Sirius and 15^- further on will strike it. 
 
 72 P. VIII. R. A., 8h. 2om. i8s. ; Dec., 23 41.3'. A 
 beautiful double. A 6, red ; B 9}, green. D., 41.9". 
 Line from Rigel to Sirius and 25^ beyond, and another 
 at right angles N. W. 2. 
 
 35 JgL VIII. (H. 1521.) R. A., 7h. i8m. 545. ; Dec., 
 
 13 2.9'. A cluster large but little condensed, consisting 
 of rather large stars. Line from /3 Canis Majoris through 
 Sirius and 15 beyond. 
 
 38 Jp VIII. (H. 1551.) R. A., yh. 3 im. 33 s. ; Dec., 
 
 14 14.3'. A splendid field of stars, somewhat lozenge- 
 shaped, about 15' in diameter, and led by a fiery red 7th 
 mag. star. It contains a double star, A 7^, B 8, both 
 bluish white. D., 7.3". Line from ft Can. Majoris, just 
 under Sirius, and 13 beyond. 
 
 46 M. (H. 1564.) R. A., 7h. 36m. 475. ; Dec., 14 27.3'. 
 A noble though rather loose cluster, more than 30' in 
 diameter, composed of stars from mag. 8 to 13, making 
 a splendid glow. It contains a delicate double, A 8J, 
 B n, both white. D., 15". " The impression left on the 
 senses is that of awful vastness and bewildering distance." 
 This object is i 20' W. and a little S. of the last men- 
 tioned. 
 
 64 W IV. (H. 1567.) R. A., 7 h. 3 6m. 595. ; Dec., - 
 17 56.6'. A bright planetary nebula. With a power of 
 64 it resembles a dull 8th mag. star. With higher powers 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 99 
 
 it presents a bright undefined disk. Line from 3 Can. 
 Maj. through Sirius and 14 beyond. 
 
 93 M. R. A., 7h. 3901. 515.; Dec., 17 56.6'. A 
 small galaxy cluster 8' in diameter. The components 
 range in magnitude from 7 to [2, and the group is com- 
 pared by Smyth to a star-fish. Line from Orion's sword- 
 cluster through Sirius and 16 beyond. " The unlucky 
 Chevalier d'Angos, of the Grand Master's Observatory at 
 the summit of the palace at Malta, mistook this object 
 for a comet ; from which, and even still more suspicious 
 assertions, my excellent friend Baron de Zach was in- 
 duced to term any egregious astronomical blunders Ango- 
 siades" (Smyth.) 
 
 ii ] VII. (H. 1630.) R. A.,8h. 501. 3is.; Dec.,- 
 12 32'. A large and loose but rich field. A close dou- 
 ble in the centre, and a bright yellow 6th mag. star sf. 
 Line from fi Can. Maj. just below Sirius and 21^ further 
 on. 
 
 63 I VII. (H. 1678.) R. A., 8h. 32m. 345.; Dec., 
 29 33.6'. A compressed cluster. Line from Rigel 
 through Sirius and 30 J beyond. 
 
 ARIES (THE RAM). 
 
 An inconspicuous, but astronomically important con- 
 stellation. Mean R. A., 2h. 25'; Dec., + 13; stars, 148. 
 
 a. (Hamal.) R. A., 2h, om. 585.; Dec., + 22056'. A 
 star with a telescopic companion. A 3, yellow ; B 11, 
 purple. Difference of R. A., 19.55. 
 
 /?. (Sheratan.) R. A., ih. 48m. 335.; Dec., + 20 16.2'. 
 A pretty double, but will prove decidedly difficult in a 
 
IOO THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 small telescope. A 3, pearly white ; B n, dusky. Differ- 
 ence of R. A., 7.45. 
 
 y. (Mesarthim.) R. A., ih. 471*1. 295.; Dec.,-f 18 
 45.3'. A fine double. A 4^, white; B 51, pale gray. D., 
 
 8.3*-. 
 
 A. R. A., ih. 5im. 475.; Dec., + 23 3.6'. A fine dou- 
 ble. A 5^, yellowish white ; B 8, blue. D., 37. 5". This 
 star is the apex of an oblique triangle of which a and ft 
 form the base. 
 
 14. R. A., 2h. 3m. 95.; Dec,, + 25 25.3'. A beautiful 
 triple. A 5 J, white ; B loj, blue ; C 9, lilac. D., AB 
 82.6", AC 106.5". Tm 's star is 2 40' N. and a little W. 
 of a. 
 
 30. R. A., 2h. 3om. 375. ; Dec., + 24 10.2'. A fine 
 double. A 6, topaz yellow ; B 7, pale gray. D., 38.3". 
 Line from y Pegasi through Hamal and 7 beyond. 
 
 41. R. A., 2h. 43m. 305.; Dec.,+ 26 48.5'. A coarse 
 quadruple star, which our observer will probably see 
 triple or even only double. A 3, white ; B 13, deep blue; 
 C n, lurid ; D 9, pale gray. D., AB 21.2", AC 34", AD 
 125.9". This star is the lucida of the scarcely recognized 
 constellation Musca Borealis. 6J from s on line to y 
 Androm. 
 
 AURIGA (THE CHARIOTEER). 
 
 A fine constellation, rich in telescopic objects. Mean 
 R. A., 5h. 27m.; Dec., + 42 ; stars, 239. 
 
 a. (Capella.) R. A., sh. 8m. 335.; Dec.,+ 45 53.5'. 
 A splendid star of mag. i, bright white, with four distant 
 companions, of which only one E. 10, D. 158" will be 
 seen in a small telescope, and then only with much diffi- 
 culty. 
 
THE AMATEUR TELESCOPIST's 
 
 ft. (Menkalinan.) R. A., 5h. 51111. 285.; Dec., + 44 
 56'. A beautiful star with a distant companion. A 2, 
 lucid yellow ; B ioj, bluish. D., 184". 
 
 6. R. A., 5h. 52m. 125. ; Dec., + 37 12.4'. A quad- 
 ruple group. A 4, brilliant lilac ; B yj, C 10, pale yel- 
 low ; Dp, yellowish. D., AB 2.08", AC 45. 5", AD 125.1". 
 
 A. R. A., 5h. nm. 225.; Dec., + 40 0.6'. A triple 
 group. A 5, pale yellow ; B 13, C 9^, plum-color. D., 
 AB 40.4", AC 121.5". Many stars in field. This star is 
 about 5 from Capella on a line toward Bellatrix. 
 
 GO. R. A., 4h. 5im. 475.; Dec., + 37 43.4'. A beau- 
 tiful double. A 4, pale red ; B 8, light blue. D., 5.9'. 
 About one-third the distance between Capella and the 
 Hyades. 
 
 26. R. A., 5h. 3im. 345.; Dec., + 30 25.6'. A fine 
 double. A 5, pale white ; B 8, violet. D., 12.3". Line 
 from s Orionis through 2, Tauri, and something less than 
 10 on. 
 
 41. R. A., 6h. 3m. ics. ; Dec., + 48 44', A neat dou- 
 ble. A 6, silvery white ; B 7, pale violet. D.. 7.7". Line 
 from (3 Tauri through /3 Aurigse and 4 beyond. 
 
 56. R. A., 6h. 38m. 488.; Dec., + 43 41.1'. A double 
 star. A 6, silvery white ; B 8J, lilac. Just north of a line 
 from a through /?, and extended as far beyond. 
 
 4 B. R. A., 4h. 3im. 415.; Dec., + 26 43.7'. A pretty 
 double. Both mag. 7, both double. D., 3.7". Line from 
 Capella through and 18 on. 
 
 96 B. R. A., 5h. 23m. 435.; Dec., + 49 18.3'. A neat 
 double. Both mag. 8, both very white. D., 7.7". About 
 4 from Capella on line towards ft Urs. Maj. 
 
 2139 B - A - c - R - A - ( l8 7), 6n - 2 7 m - 3 6s -; Dec -> + 3 8 
 32.8'. A superb orange-red star, of mag. 6.5. Line from 
 a 2% E. of ft and 8 further on. 
 
roz TbE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 33 JL VII. (H. 1067.) R. A., 5h. 12111. 95.; Dec., + 39 
 13.7'. A rich field of small stars, the most prominent 
 among which is a bright orange 7^ mag. star. About 
 7 from Aldebaran on a line towards Bellatrix. 
 
 39 ]VII. (H. 1114.) R.A., 5h. 2om. 3 8s.; Dec., + 35 
 13.3.' A compressed cluster about 3' in diameter, 12 
 from Capella on a line towards Betelgeuse. This cluster 
 is in a rich neighborhood, there being no less than four 
 others so near it that they may all be included in a circle 
 4 in diameter. 
 
 38 M. (H. 1119.) R. A., 5h. 22 m. 2 s.; Dec., + 35 
 44.1'. A rich cluster 10' in diameter, very near the last- 
 mentioned one towards the N. and a little W. The most 
 clustering part forms an oblique cross with a pair of larger 
 stars in each arm, and a conspicuous one in the centre. 
 Line from Rigel through ft Tauri and about 7 beyond. 
 
 36 M. (H. 1166.) R. A., 5 h. 29m. 2 s.; Dec., + 34 
 4.2'. A splendid though open cluster ; another of the 
 above group. In the cluster is a neat double star. A 8, 
 B 9, both white. D., 12". Line from middle of Orion's 
 belt through 2 Tauri and about 13 beyond. 
 
 37 M. (H. 1295.) R. A., 511. 45m. 25.; Dec., -f 32 
 31.3'. A magnificent cluster, 24' in diameter. " The 
 whole field strewed, as it were, with sparkling gold-dust." 
 (Smyth.) " Extremely beautiful, one of the finest of its 
 class. Gaze at it well and long." (Webb.) " Wonder- 
 ful loops and curved lines of stars." (Rosse.) Line from 
 Aldebaran through fi Tauri and 7 on. 
 
 BOOTES. 
 
 A fine and rich constellation. Mean R. A., i4h. 3001.; 
 Dec., + 3- Stars, 319. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 103 
 
 a. (Arcturus.) R. A., i4h. lorn. 395.; Dec., + 19 
 45.7'. A magnificent star, usually rated as next to Sirius 
 in brilliancy. It has a minute distant lilac companion of 
 the nth magnitude, which is quite beyond the powers 
 of a small telescope. 
 
 d. R. A., i5h. nm. 33.; Dec., + 33 43.7'. Star with 
 distant companion. A 3^, pale yellow ; B 8^, light blue. 
 D., 104.6". 
 
 f. R. A., i4h. 4om. us.; Dec., + 27 32.2'. A famous 
 and most beautiful double which Struve designated as 
 " Pulcherrima." A3, pale orange; B 7, emerald green, 
 the colors in lovely contrast. D., 2.77". Line from 
 Mizar (8> Urs. Maj.) through rj. Urs. Maj. to the star in 
 question, which is about midway between Arcturus and 
 a Coronae Borealis. 
 
 H. R. A., i4h. 9m. 315.; Dec., 52 18.1'. A fine 
 double. A 5!, pale white; B 8, bluish. D., 12.9". 
 Line from s Urs. Maj. through Mizar and 6 further 
 on. 
 
 //. R. A., ish. 2om. 2 is.; Dec., + 37 45- 8 '- A 
 double in a small telescope, but triple in a larger one. 
 A 4, flushed white ; B 8, greenish white. D,, 108.5". A 
 line from rj Urs. Maj. through ft Bootis and 4 beyond 
 will pass within i of this star. 
 
 . R. A., i4h. 46m. i8s.; Dec., + 19 33.6'. A fine 
 binary star. A 3^, orange ; B 6^, purple. D., 4.19". 8-J 
 from a on line to /? Serpentis. 
 
 n. R. A., i4h. 35m. 335.; Dec., + 16 53.5'. A fine 
 double. A 3!, B 6, both white. D., 5.96". 7 from Arc- 
 turus on a line towards a Serpentis. 
 
 44. R. A., i5h. om. us.; Dec., -f 48 5'. A remark- 
 able and highly interesting binary with a period of about 
 261 years. A 5, pale white ; B 6, lucid gray. D., 4.99". 
 
104 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 Sir W. Herschel calls this a miniature of Castor. 7^ from 
 ft on line towards the N. pole. 
 
 220 P. XIII. R. A., 13!!. 45m. 125.; Dec., + 21 49.4'. 
 A wide double. A ;, B 8, both flushed white. D., 85.8". 
 In the same field is 6 Bootis. This star is 6 from Arc- 
 turus towards Coma Berenices. 
 
 1850 2. R. A., i4h. 2 3 m. 425.; Dec., + 28 46.7'. A 
 pretty double. A 6, B 7, both very white. D., 25.2". 
 It is about i W. of a line from a to ft, and 8 from the 
 former. 
 
 CAMELOPARDUS. 
 
 A large but not very important or conspicuous modern 
 constellation. Mean R. A., 5h.; Dec., 70 ; stars, 211. 
 
 i. R. A., 4h. i 9 m. 233.; Dec., + 53 33.3'. A neat 
 double. A 7^, white ; B 8^, sapphire blue. D., 10.2". 
 Nearly midway between a Persei and d Aurigae. 
 
 97 P. III. R. A., 3 h. 3 3 m. 3 8s.; Dec., + 59 &*' A 
 lovely but rather difficult double. A 6, orange with scar- 
 let glare ; B 9, blue. D., 55.6". 15 from 6 Persei on 
 line towards Polaris. 
 
 485 2. R. A., 3h. 58m. 155.; Dec., + 62 3.4'. A 
 pretty double. Both 6^ ; A white, B bluish white. D., 
 17.8". Line from a Cassiopeae through d Cass. and 15 
 beyond. 
 
 269 P. IV. R. A., 5h. 4m. 265.; Dec., + 79 6.1'. A 
 fine double. A 5^, light yellow ; B 9, pale blue. D., 
 20.2". Line from j3 Draconis through Polaris and 10 on. 
 
 159 P. VII. R. A., yh. 35m. 265.; Dec., + 65 24.9'. 
 A fine double. Both mag. 8, both white. D., 15.6". In 
 a rich neighborhood. Line from Capella to 6 Aurigae and 
 15 beyond. 
 
THE AMATEUR TELESCOPISl's HANDBOOK. 105 
 
 CANCER (THE CRAB). 
 
 A constellation of little brilliancy, but important from 
 its position in the zodiac. Mean R. A., 8h. 2501.; Dec., 
 + 8 ; stars, 179. 
 
 6. R. A., 8h. 25m. 208.; Dec., 18 28.1'. A star with a 
 rather dull companion, which latter, however, is of interest 
 on account of what seems to be a gradual decrease in its 
 light. A 5 J, yellow ; B 9, gray. This is Smyth's rating, 
 but Knott pronounces B of mag. 12, and suggests that it 
 should be watched. D., 60.7". A line from Regulus to d 
 Cancri and 3 beyond will come to a point i S. of this 
 star. 
 
 i. R. A., 8h. 4om. 33.; Dec., + 29 9.7'. A beautiful 
 double. A 51, pale orange ; B 8, clear blue. The colors 
 finely contrasted. D., 30.5". 
 
 118 P. VIII. R. A., 8h. 32m. 485.; Dec., + 20 4'. 
 A 8, B 8J, both pale white. D., 57.2". About one-third the 
 distance from Pollux to Regulus, about 2 south of a line 
 so drawn. 
 
 124 P. VIII. R. A., 8h. 3301. 323.; Dec., + 19 56'. A 
 fine triple. A 7, pale yellow ; B 7^, dusky ; C 6^, lucid 
 white. D., AB 45.8", AC 93.1". About E. and a little 
 S. of the last object. 
 
 129 P. VIII. R. A., 8h. 34m. 6s.; Dec., + 20 3.5'. A 
 beautiful double. A 7, golden yellow ; B 10, blue. D., 
 20.5". Close to the east of the last object. 
 
 211 Birm. R. A., 8h. 49m. us.; Dec., + 17 39'. A 
 fine red star varying from mag. 7 to y-J. It is i N. E. 
 of a line from a to #, at a point 3 from the latter. 
 
 194 B. R. A., gh. im. ys.; Dec., + 23 24.9'. A pretty 
 
106 THE AMATEUR TELESCOPIST*S HANDBOOK. 
 
 double. Both 7^, both white. D., 7.3". Line from 
 Leonis through e Leonis and 9 beyond. 
 44 M. (H. 1681.) R. A., 8h. 33m. 555.; Dec., + 20 
 19.4'. The Praesepe, a noble cluster of large dimensions, 
 easily visible to the naked eye as a nebulous spot resem- 
 bling a detached scrap of the Milky Way. It is a superb 
 object in the telescope. Draw a line from Castor to Pollux 
 and on to three times the distance between them. 
 
 67 M. (H. 1712.) R. A., 8h. 45m. los. ; Dec., -f 12 
 12.7'. A rich clustering mass of stars of mags. 9 and 10, 
 followed by a "crescent of stragglers." It is 2 W. of a. 
 
 CANES VENATICI (THE HUNTING DOGS). 
 
 A modern constellation formed by Hevelius. Mean 
 R. A., i 3 h. 5m.; Dec., + 40 ; stars, 139. 
 
 a. (Cor Caroli.) R. A., i2h. 50111. 535.; Dec., 38 54.7'. 
 A fine double. A 2j, flushed white ; B 6^, pale lilac. 
 D., 20". 
 
 2. R. A., i2h. lorn. 375.; Dec., 41 16.5'. A beautiful 
 double. A 6, golden yellow ; B 9, smalt blue. D., 11.5". 
 Line from Polaris through d Ursae Majoris, and 17 
 beyond. 
 
 1645 2. (1880.) A beautiful double, closely following 
 a star (1642 ^), in R. A., i2h. 2om. ; Dec., + 45 25'. 
 A 7, B 7^, both yellowish white. D., 10.4". "A lovely 
 pair as I ever saw." (Bird.) To find 1642 2, draw a 
 line from a Ursae Majoris through y Urs. Maj. and 8J 
 beyond. 
 
 94 M. (H. 3258.) R. A., i2h. 45. 43*.; Dec., + 41 
 43.3'. A comet-like nebula, 2.5' in diameter. It is of a 
 fine pale white color, brightening towards the centre. 2 J 
 from a, towards $ Ursae Majoris. 
 
* THE AMATEUR TELESCOPIST*S HANDBOOK. 107 
 
 96 ip I. (H. 3437.) R. A., i 3 h. sm. 515.; Dec.,+ 37 
 39.2'. A large nucleated nebula, 6' long, 1.5' wide. Line 
 from /* Ursae Maj. to Cor. Caroli and 3^ beyond. 
 
 97 J$ I. (H. 3459.) R. A., i 3 h. 8m. 235.; Dec., + 37 
 10.8'. A bright large nebula, brighter towards centre. 
 About J from the last object, S. and a little E. 
 
 63 M. (H. 3474.) R. A., i3h. lorn. 535.; Dec., + 42 
 36.7'. A faint oval nebula, 9' or 10' long, and nearly 4' 
 wide, with a nucleus like a small star. Line from ft Leo- 
 nis through Cor Caroli and 5 J beyond. 
 
 51 M. (H. 3572.) R. A., i 3 h. 35m. 135.; Dec., + 47 
 45.2'. A faint double nebula, with centres 4' 45" apart, 
 but borders in contact. In a 5 -inch telescope, the 
 southern object " resembles a ghost of Saturn with its ring 
 in a vertical position." This system bears, according to 
 Sir John Herschel, a strong resemblance to our own. It 
 is one of the most celebrated of the Earl of Rosse's spiral 
 nebulae. It lies 3 from rj Ursse Majoris, on a line from 
 Polaris through Urs. Maj. 
 
 3 M. (H. 3636.) R. A., i 3 h. 37m. 3 s.; Dec., + 28 
 55.3'. A brilliant and beautiful globular cluster of not 
 less than 1,000 small stars, blazing towards the centre. 
 A noble object, 5' or 6' in diameter. About iS from 
 s Bootis on line drawn across the southern base of the 
 cluster in Coma Berenices. 
 
 CANTS MAJOR (THE GREATER DOG). 
 
 A fine constellation, distinguished by including within 
 its boundaries the brightest star in the heavens. Mean 
 R. A., 7h. ; Dec., 30 ; stars, 161. 
 
 a. (Sirius.) R. A., 6h. 4om. i8s. ; Dec., 16 33.7'. 
 The Dog-star, the most brilliant and splendid of all the 
 heavenly host. It is a magnificent object in the telescope, 
 
Id8 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 although a small instrument will fail to show even its 
 principal companion. Mr. Proctor thinks this comes would 
 be visible in a 3-inch telescope, but this is not at all in 
 accord with my experience. Sir William Herschel says 
 that the entrance of Sirius into the field of his 4o-foot 
 telescope was heralded by a dawning like that of a 
 sunrise, and that its lustre when within the field was 
 intolerable to the eye. 
 
 p. (Mirzam.) R. A., 6h. 17111. 525. ; Dec., 17 54.3'. 
 A bright star with a companion. A 2 J-, fine white ; B 9, 
 dusky gray. D., 185.2". Another 9 mag. star in field. 
 
 d. (Wezen.) R. A., ;h. 3m. 555. ; Dec., - 26 13.1'. 
 A star with companion. A 3^, light yellow ; B 7^, very 
 pale. D., 265.9". Other small stars in field. 
 
 . (Adhara.) R. A., 6h. 54m. i8s. ; Dec., 28 49.3'. 
 A pale orange 2\ mag. star, with a 9 mag. companion at 
 a distance of 7.7", and another of mag. 7 further off. 
 Line from middle of Orion's belt through j3 and 14^ on. 
 
 77. R. A., 7h. i9m. 445. ; Dec., 29 5.3'. A beautiful 
 star with distant companion. A 3, pale red ; B 7j, dull 
 gray. Two small stars following. D., 178.6". Line 
 from fi through # and 5 on. 
 
 r l . R. A., 6h. 3im. 335. ; Dec., 18 34.1'. A neat 
 double. A 6J, pale garnet ; B 8, gray. D., 17.4". Fol- 
 lowed in sf by r 2 . It is 3 S.E. of Sirius, and 3^ from 
 Mirzam. 
 
 17. (n\) R. A., 6h. 5om. i8s. ; Dec., 20 15.9". A 
 wide quadruple. A 6, flushed white ; B pj, ruddy ; C 9^, 
 ruddy; D 10, dusky. D., AB 45", AC 52.5", AD 125". 
 This is the middle one of three small stars about 4^ 
 S.S.E. of Sirius: 
 
 22. R. A. (1870), 6h. 56m. 328. ; Dec., 27 45'. A 
 fine red star ; mag., 3^. It is ij from on a line to tf. 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. IOQ 
 
 . R. A. (1870), yh. i7m. 395. ; Dec., - 25 30.8'. 
 An intense fiery red star ; mag., 7. A line from Bella- 
 trix through Sirius and 13 on will come within 40' S.E. 
 of it. 
 
 41 M. (H. 1454.) R. A., 6h. 42m. 135. ; Dec., 20 
 37.8'. A scattered cluster in 5 groups, the central one 
 the richest. A splendid object. It is 4 almost due S. of 
 Sirius, a little to the E. 
 
 578 Dun. (H. 1463.) R. A., 6h. 45m. 55. ; Dec., 
 
 35 5 2 -9 A globular cluster brightening towards the 
 centre. Line from Bellatrix through Mirzam, and 21 on. 
 
 12 W VII. (H. 1512.) R. A., yh. i 2 m. 515. ; Dec., 
 
 15 26.5'. A tolerably compressed but extensive clus- 
 ter. It is a singular group of very lucid stars, nearly all 
 of mag. 10. The most compressed part occupies about 
 one-third of the field with a power of 66. Line from a 
 Tauri through Bellatrix to a point y| W.N.W. of Sirius. 
 
 17 I VII. (H. 1513.) R.A., 7h. i4m. 285.; Dec.,- 24 
 45.2'. A beautiful cluster of slightly elongated form, 
 consisting of a rich gathering of minute stars surrounding a 
 bright white 6th mag. star. Line from 8, Orionis through 
 Sirius and 12 on. 
 
 CANIS MINOR (THE LESSER DOG). 
 
 A small constellation, of which the principal interest 
 centres in its lucida. Mean R. A., 7h. 2ym. ; Dec., + 7 ; 
 stars, 55. 
 
 a. (Procyon.) R. A., 7h. 33m. 335.; Dec., + 5 30.5'. 
 A famous and beautiful star of mag. i-J-, although it cer- 
 tainly deserves, in the opinion of many astronomers, to 
 be rated higher. It has several companions, all of which 
 are beyond the reach of a small telescope. 
 
110 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 ft. (Gomelza.) R. A., ;h. 2im. us.; Dec., + 8 30.6'. 
 A wide though difficult triple. A 3, white ; B 12, 
 orange ; C 10, flushed. C itself is coarsely double, having 
 a 10 mag. companion. D., AB 122.3", AC 138.8". 
 
 5. R. A., yh. 26m. 455.; Dec., + 8 33.2'. A fiery red 
 star, varying from 7^ to less than 12 mag. i-J E. of j3. 
 
 14. R. A., yh. 52m. 393.; Dec., -}- 2 31'. A wide 
 triple. A 6, pale white ; B 8, bluish ; C 9, blue. D., AB 
 75", AC 115". Line from y Geminorum through Pro- 
 cyon and 4^ on. 
 
 CAPRICORNUS (THE GOAT). 
 
 A zodiacal constellation, rather dull to the naked eye, 
 but of importance astronomically. Mean R. A., 2oh. 4om. ; 
 Dec., 1 8 ; stars, 154. 
 
 a. (Giedi.) R. A., 2oh. nm. 575.; Dec., 16 53.1'. 
 A remarkable multiple object, a 1 and o? are 376.1" apart. 
 a 1 is composed of four stars, of magnitudes 3, n, n, and 
 9^ ; o? of three, of magnitudes 4, 9, and 14. A small 
 telescope will probably not show more than four stars in 
 the entire group. 
 
 ft. (Dabih.) R. A., 2oh. 1401. 505.; Dec., 15 7.8'. 
 A wide pair of stars. A 3^, orange yellow ; B 7, sky blue. 
 D., 205". 
 
 o a . R. A., 2oh. 23m. 365.; Dec., 18 56.7'. A fine 
 double. A 6, B 7, both bluish. D., 22.1". It is 2^ E. a 
 little south from a group of 5th mag. stars, 4 from ft on 
 a line from a. 
 
 6. R. A., 2oh. i3m. 35.; Dec., 19 27.8'. A star 
 with telescopic companion. A 5^, yellow ; B 10, violet. 
 D., 54.1". Line from d \ Q S. of 6 and 11^ on. 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. Ill 
 
 545 Birm. R. A., 2oh. lorn. 405.; Dec., 21 39.3'. A 
 lovely red star, probably variable, as the estimates of its 
 magnitude vary from 6 to y|. Sir J. Herschel says of it, 
 " Pure ruby, perhaps the finest of my ruby stars." It is 
 8 40' almost due S. of a, and almost exactly three times 
 as far from a as f3 is. 
 
 312 P. XX. R. A., zoh. 43m. 305.; Dec., 27 46.4'. 
 A beautiful double. A ;|, pale yellow; B 8-J, blue. 
 D., 18.7". It is S. and a little W. from GO, a 4th. mag. 
 star which is the southernmost of two 4th mag. stars, 2^ 
 apart, about 14 S. E. of a. 
 
 72 M. (H. 4608.) R. A., 2oh. 47m. 245. ; Dec., 12 
 56.6'. A globular cluster of very minute stars, about 1.53' 
 in diameter. Line from a Aquarii through ft Aquarii 
 and nearly 12 on. 
 
 73 M. (H. 4617.) R. A., 2oh. 52m. 555.; Dec., - 13 
 3.6'. A rather poor field, which Smyth records out of re- 
 gard to Messier's memory. It exhibits little compression. 
 It follows the last object by about 5m. of R. A., and 7' 
 southward. 
 
 30 M. (H. 4687.) R. A., 2ih. 34m. 75.; Dec., - 23 39'. 
 A fine pale white cluster, nebulous in small telescope. It 
 is somewhat elliptical, and brightens to a blaze in the cen- 
 tre. A line from /? to 2, and 4 on will reach a point less 
 than i S. of it. 
 
 CASSIOPEA. 
 
 A superb constellation, one of the richest in the 
 heavens. Mean R. A., oh. 55m.; Dec., + 60 ; stars, 134. 
 
 a. (Shedir.) R. A., oh. 34m. i6s.; Dec., + 55 56.3'. 
 A beautiful double, A 3, pale rose ; B p-J, smalt blue. 
 
112 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 D., 62.5". A is considered variable by some astrono- 
 mers. 
 
 ft. (Caph.) R. A., oh. 3m. i8s.; Dec., + 58 32.6'. 
 A star with a distant companion. A 2^, whitish ; B n, 
 dusky. D., 297". Very difficult with a small tele- 
 scope. 
 
 y. R. A., oh. 5om. 45.; Dec., + 60 7.2'. A beautiful 
 brilliant white 3d mag. star, with others in field. 
 
 rf. R. A., oh. 42m. 265.; Dec., + 57 13.9'. A superb 
 binary star. A 4, B y-j-. D., 5.7", and decreasing.. The 
 estimates as to the colors of the components differ con- 
 siderably ; Smyth giving them as pale white and purple, 
 and no less than six other colors being assigned to them 
 by different observers. The latest estimate is yellow and 
 red. 
 
 R. R. A., 23h. 52m. 495.; Dec., + 50 46.4'. A vivid 
 red star with a minute blue companion 20" distant. It 
 varies in 426 days from mag. 5 to below mag. 12. Line 
 from 6 through a and 8 on. 
 
 4. R. A., 23h. i9m. 575.; Dec., + 61 40.7'. A double 
 star in a small telescope ; in a larger one, quadruple. A 5, 
 pale yellow ; B 9, yellowish. D., 98.1". 2 due N. of /?. 
 
 9. R. A., 23h. 58m. 335.; Dec., + 61 40.5'. A pair 
 of stars ; in a large telescope, a group of four. A 6, 
 white ; B 8, deep yellow. D., 244". 2 E. and somewhat 
 N. from y. 
 
 i Birm. R. A., oh. 3m. 385.; Dec., + 63 20.4'. A fine 
 ruby star. Mag., 8-J-. About ij due N. of /?. 
 
 163 2. R. A., ih. 43m. 175.; Dec., + 64 18.1'. An 
 exquisite double. A 6J, golden red ; B 9, blue. D., 
 34.9". 9 from B on line to Polaris. 
 
 101 P. XXIII. R. A., 2 3 h. 24m. 565. ; Dec., + 57 
 56.6'. A remarkable multiple star, which, however, our 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 11$ 
 
 observer will only see double. A 5, light yellow ; B 7^, 
 white. Line from 6 to y and 12 on. 
 
 3053 2. R. A., 23h. 56m. 575.; Dec., + 65 29'. A 
 beautiful double. A 6, very yellow; B 8, blue. D., 15". 
 Line from y Andromedae to y Cassiopeae and 8 on. 
 
 159 J[ I. (H. 158.) R. A., oh. 45m. 503.; Dec., + 46 
 57.9'. An "almost planetary" nebula, 20" in diameter. 
 Line from Polaris to ft and u^ on. 
 
 103 M, (H. 341.) R. A., ih. 25m. 565.; Dec., + 60 
 7.1'. A brilliant and beautiful fan-shaped cluster. About 
 i J E. and a little N. of d. 
 
 31 ] VI. (H. 392.) R. A., ih. 3 8m. 395.; Dec., + 60 
 41.3'. An elegant, irregular cluster. About 2 from last 
 object on line from 6. 
 
 30 W VI. (H. 5031.) R. A., 2 3 h. 5 im. 355.; Dec., 
 + 56 6.2'. A splendid galaxy cluster of minute stars ; 
 " a very glorious assemblage both in extent and richness ; 
 a mere condensed patch in a region of inexpressible 
 splendor, spreading over many fields." Discovered by 
 Miss Caroline Herschel. It is 2^ from ft on a line 
 towards Algol. 
 
 CENTAURUS (THE CENTAUR). 
 
 A large constellation, most of which is below the hori- 
 zon in our latitudes, or so near it as to offer little oppor- 
 tunity for its study. Mean R. A., 13!!. 3501.; Dec., 50. 
 It presents to us but one object of interest. 
 
 83 M. (H. 3606.) R. A., i3h. 3om. 495.; Dec., - 29 
 1 8.8'. A large and bright nebula, nucleated in centre. 
 In a large telescope it appears as a 3-branched spiral. 
 Line from rj Virginis to y Hydrae and 8 on. 
 8 
 
114 THE AMATEUR TELESCOPISl's HANDBOOK. 
 
 CEPHEUS. 
 
 A highly interesting northern constellation, although of 
 little brilliancy to the naked eye. Mean R. A., 22h.; 
 Dec., + 73 ; stars > 2 94- 
 
 a. (Alderamin.) R. A., 2ih. 15111. 565.; Dec., + 62 
 7.1'. A star with a difficult distant companion. A 3, 
 white ; B 10, pale blue. D., 208.9". 
 
 ft. (Alphirk.) R. A., 2ih. 27m. 145.; Dec., + 70 4.6'. 
 A beautiful double. A 3, white ; B 8, blue. D., 13.3". 
 
 d. R. A., 22h. 25m. 55.; Dec., + 57 51.1'. A lovely 
 though wide double. A 4^, orange tint ; B 7, fine blue, 
 the colors well contrasted. A is variable from mag. 3^ to 
 4^. Its interval from maximum to minimum is 3d. 19!!., 
 and from minimum to maximum id. i4h. D., 19.3". 
 
 H. R. A., 2oh. i2m. 355.; Dec., + 77 22.7'. A neat 
 double. A 4^, bright white ; B 8-J-, smalt blue. A fine 
 object. D., 7.2". A line drawn from y Androm. through 
 d Cassiopese to within 12 of Polaris will find this star. 
 
 //. R. A., 2ih. 4om. 8s.; Dec., + 58 16.5'. A richly 
 colored star with two companions. It varies from mag. 4 
 to 6. Sir W. Herschel says : " It is of a very fine deep 
 garnet color, . . . and a most beautiful object, espe- 
 cially if we look for some time at a white star before we 
 turn our telescope to it, such as #, which is near at hand." 
 It is 5 from or on a line towards /3 Pegasi. 
 
 . R. A., 22h. om. 355.; Dec., + 64 5. 4'. A splendid 
 double. A 5, B 7, both blue. D., 6.6". It is 7 from /? 
 on line towards d. 
 
 248 P. XXI. R. A., 2ih. 35 m. 375.; Dec., + 56 59-5'- 
 A neat triple. A 6, pale yellow ; B and C both 8-J-, both 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 115 
 
 gray. D., AB 11.7", AC 19.8". A line from Polaris 
 through /? and 13 on will pass within ^ W. of this 
 star. 
 
 256 P. XXI. R. A., 2ih. 36m. 573.; Dec., + 57 5'. 
 A very neat double. A 8, white ; B 9, pale violet. D., 
 12.6". Line from y Cassiopeae through /? Cassiopeae and 
 3 on. 
 
 147 B. R. A., 2ih. 4801. 175.; Dec., + 55 16.8'. A 
 pretty double. A 6, greenish white ; B 7^, bluish white. 
 D., 20. i". Line from y Cygni to a Cygni and 16 
 on. 
 
 2893 2. R. A., 22h. lom. 545.; Dec., + 72 45.8'. A 
 fine double. A 6, yellowish; B 8, white. D., 28.8". 
 About midway between /3 and y. 
 
 U. R. A., oh. 52m. 335.; Dec., -f 81 17'. Ceraski's 
 2d variable, the most rapid yet known. It varies from 
 mag. 7 to 9, and its periods of 
 maximum, minimum, and change 
 are 2 hours each. According to 
 Knott, it is bluish at maximum 
 and ruddy at minimum. I ap- 
 pend a diagram (from Webb) 
 which will assist in finding this 
 star. 
 
 42 W VI. (H. 4590.) R. A., 
 2oh. 29m. 175.; Dec., + 60 16.3'. 
 FlG ' I3 ' A large and rich cluster of 
 
 minute stars. 2 from ?/ on line from e Cassiopeae. 
 
 52 M. (H. 4957.) R. A., 23h. 19111. 2is.; Dec., + 60 
 59.5'. An irregular cluster, nebulous in a small telescope, 
 but showing some stars. It is of a somewhat triangular 
 form, with an orange -tinted 8th mag. star at one angle. 
 At the distance between ft Cassiopeae and a Cephei. 
 
Il6 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 CETUS (THE WHALE). 
 
 The largest of all the constellations. Mean R. A., 
 ih, 35m.; Dec., 18; stars, 301. 
 
 a. (Menkab.) R. A., 2h. 56m. 315.; Dec., + 3 39.5'. 
 A star with a distant companion. A 2-J-, bright orange ; 
 B 10, pale gray. Diff. of R. A., 29.6". A fine blue 5th 
 mag. star in field towards N. 
 
 q. R. A., ih. 3m. 35.; Dec., 10 45.9'. A probably 
 variable star with distant companion. A 3^, yellow ; B 
 10, lead color. D., 2.25". 
 
 2. R. A., ih. 46m. 25.; Dec., io52.8'. A 3^, topaz 
 yellow ; B 9, white. D., 185". 
 
 o. (Mira.) R. A., 2h. i3m. 475.; Dec., 3 28.7'. A 
 wonderful variable. It changes from mag. 2 to invisi- 
 bility, according to Smyth ; from mag 1 . 2 to mag. 10, ac- 
 cording to Webb ; and from mag. 1.7 to mag. 8 or 9 on 
 Struve's scale, according to Schonfeld. Its period is 
 33 id. 8h. 14111. i6s., according to Argelander. Mira is 
 about half-way between y and 2,. 
 
 26. R. A., oh. 58m. 95. ; Dec., + o 46.6'. A neat dou- 
 ble. A 6J, pale topaz ; B 9^, lilac tint. D., 16". Mid- 
 way between y Pegasi and Ceti. 
 
 37. R. A., ih. 8m. 515. ; Dec., 8 30.7'. A fine though 
 wide quadruple. A 6, white ; B 7^, light blue ; C 8, 
 yellow ; D TO, violet. D., AB 48.3", CD 20.5". It is 
 2^ almost due E. of 0, and 2 40' N. N. W. of rj. 
 
 66. R. A., 2h. 7m. 8s. ; Dec., 2 54.3'. A beautiful 
 double. A 7, pale yellow ; B 8-J, sapphire blue. D., 
 15.35". It is i 40' W. and a little N. from Mira. 
 
 113 P. O. R. A., oh. 28m. 525.; Dec., 9 5.3'. A 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 1 17 
 
 fine double. A 7, cream yellow ; B 9, smalt blue ; D., 
 19.9". 10 from ft on line towards y Pegasi. 
 
 146 P. O. R. A., oh. 35m. 6s. ; Dec., - 4 57.3'. A 
 beautiful though wide double. A 6^, pale topaz ; B 9, 
 violet tint. D., 65". Line from rj to a Pegasi ; the star 
 will be found 9 from the former. 
 
 191 P. I. R. A., ih. 46m. us.; Dec., + 10 16". A 
 beautiful close double. A y-J, B 8, both lucid white. It is 
 13 from a Arietis (to which constellation it really be- 
 longs) on a line to 6 Ceti. D., 3.6". 
 
 150 2. R. A., ih. 37m. ; Dec., 7 42'. A beautiful 
 double. A 8, B 8J, both very white. D., 36.2". Line 
 from i through 6 and 5 on will reach a point 40' S. of it. 
 
 23 I IV. (H. 544.) R. A., 2h. 2im. 575. ; Dec., - i 
 38'. A planetary nebula, bluish white, pale but very dis- 
 tinct. 7 from y on line towards 2,. 
 
 77 M. (H. 600.) R. A., 2h. 37m. 35. ; Dec., o 28.3'. 
 A small bright round stellar nebula. It is 3^ due S. 
 of y. 
 
 CLYPEUS SOBIESKI (SOBIESKI'S SHIELD). 
 
 A small modern constellation in the most brilliant por- 
 tion of the Milky Way. Mean R. A., i8h. 23m. ; Dec., 
 
 24 M. (H. 4397.) R. A., i8h. nm. 445. ; Dec., 18 
 26.8'. A superb field of small stars, nebulous in a small 
 telescope. It really belongs to Sagittarius, and is 3 
 N. N. W. from jj. Sag. Line from Altair to A Antinoi, 
 and as far again. 
 
 16 M. (H. 4400.) R. A., i8h. i2m. 345. ; Dec., 13 
 49.7'. A scattered but fine large stellar cluster. Line 
 from y Sagittarii to /A Sag. and 7 on. 
 
Il8 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 18 M. (H. 4401.) R. A., i8h. 13111. 305. ; Dec., - 17 
 10.8'. A somewhat long and straggling cluster of minute 
 stars. It lies 4 from ,w Sagittarii on a line towards f 
 Aquilae. Webb calls it a glorious field in very rich vicin- 
 ity, and adds, " South of it lies a region of surpassing 
 splendor." (About i.) 
 
 17 M. (H. 4403.) R. A., i8h. i4m. i6s. ; Dec., 16 
 14.9'. The singular and beautiful Horse-shoe or Omega 
 nebula, " a magnificent arched and irresolvable lumi- 
 nosity," in a splendid field. It is pronounced gaseous by 
 Huggins. It is 4^ from jn Sag. on line towards e Aqui- 
 te - y N. by E. from 18 M. 
 
 26 M. (H. 4432.) R. A., i8h. 39m. us.; Dec., 9 
 30.6'. A small and coarse but bright cluster. Line from 
 ft Herculis through /3 Ophiuci and 20^ on. 
 
 COMA BERENICES (BERENICE'S HAIR). 
 
 A constellation distinguished by the beautiful diffused 
 cluster which forms its principal part. Mean R. A., i2h. 
 3om.; Dec., + 27; stars, 117. 
 
 24. R. A., i2h. 29m. 365.; Dec., 18 58.9'. A 
 beautiful double. A 5^, orange ; B 7, emerald tint, the 
 colors very brilliant. D., 20". A little less than 13 
 from ft Leonis on line towards Arcturus. 
 
 202 P. XII. R. A., i2h. 46m. 295.; Dec., + 20 46.2'. 
 A neat double. A ;|, B 8, both white. D., 15.7". Line 
 from Spica through e Virginis and 9^ on. 
 
 92 lp I. (H. 3101.) R. A., i2h. 3om. 295.; Dec., 
 + 28 33-9'- A large club-shaped nebula, brightening 
 towards the centre. It is 2^ from 15, a 4th mag. star 
 (the largest in the cluster) in the extreme north of the 
 Tresses, on a line towards Arcturus. 
 
THE AMATEUR TELESCOPIST*S HANDBOOK. 119 
 
 24 }$ V. (H. 3106.) R. A., i2h. 3om. 505.; Dec., 
 + 26 35.7'. A curious " streak " of nebulosity, shaped 
 somewhat like a weaver's shuttle, and 15' in length. It 
 will be found difficult with anything under 4 inches. It 
 lies just outside the Tresses, or principal cluster, to the E. 
 
 53 M. (H. 3453.) R. A., i 3 h. ym. 305.; Dec., + 18 
 45 -3'- A globular cluster of minute stars of mag. 11-15. 
 "A ball of innumerable worlds." Line from Polaris 
 through 43, the easternmost of the only two 4th mag. 
 stars in the asterism, and 9^ on. 
 
 64 M. (H. 3321.) R. A., i2h. 5im. 195.; Dec., + 22 
 16.9'. A fine nebula, but difficult with small apertures. 
 Bright nucleus. Line from Spica through Virginis and 
 11 on; then ij due E. 
 
 CORONA BOREALIS (THE NORTHERN CROWN). 
 
 A beautiful little constellation. Mean R. A., i5h. 35m.; 
 Dec., + 28; stars, 87. 
 
 a. (Alphecca, or Gemma.) R. A., 15!!. 3om. 25.; Dec., 
 + 27 5.1'. A beautiful star with a distant companion. 
 A 2, brilliant white ; B 8, pale violet. Difference of R. 
 A., 1 1. 6s. 
 
 8>. R. A., i5h. 35m. 145.; Dec., + 36 59.7'. A beautiful 
 double. A 5, bluish white ; B 6, smalt blue. D., 6.3". 
 Line from e Bootis through d Bootis and 6 on. 
 
 v. R. A., i6h. i2m. 205.; Dec., + 29 27.5'. A quad- 
 ruple, but a small aperture will hardly show it more than 
 double. A 6, B 10, C 9. D., AB 86.4", AC 123.3". 12 
 from /? Herculis on line towards /3 Bootis. 
 
 T. R. A., i5h. 54m. 535.; Dec., + 26 14'. The fa- 
 mous "Blaze star" which in May, 1866, suddenly grew 
 
120 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 from a gih magnitude star to a 2d magnitude one. Prob- 
 ably a long-period variable. It is now of the pth magni- 
 tude, a, y, and 6 form a line which, prolonged 2^- de- 
 grees beyond d, will reach a point about due S. of T. 
 
 CORVUS (THE CROW). 
 
 A small and not very important constellation. Mean 
 R. A., i2h. 1 5m.; Dec., 18 ; stars, 61. 
 
 ft. R. A., i2h. 28m. 365.; Dec., 22 47.3'. A fine 
 star with two distant companions. A 2^, ruddy yellow ; B 
 7, greenish yellow ; C 8, dull gray. Difference of R. A., 
 AB 27.45.; AC 285. 
 
 #. R. A., i2h. 24m. us.; Dec., 15 54.1'. A fine 
 double. A 3, pale yellow ; B 8J, purple. D., 22.9". 
 
 CRATER (THE CUP). 
 
 A diminutive constellation, but, like Corvus, one of the 
 original 48. Mean R. A., nh. 1501.; Dec., 18 ; stars 
 95- 
 
 a. (Alkes.) R. A., loh. 54m. 275.; Dec., 17 42.9'. 
 A fine star, notable for its two beautiful companions in 
 the field. A 4, orange tint ; B 8, intense blood color ; 
 C 9, pale blue. B is the lovely star next described. 
 
 R. R. A., loh. 55m. 8s.; Dec., 14 29.4'. A beau- 
 tiful crimson or scarlet star, varying from mag. 8 to 9. 
 Its color seems to be growing paler. 
 
 17. R. A., nh. 26m. 495.; Dec., 28 39.6'. A neat 
 double. A 5^, lucid white ; B 7, violet tint. D., 8.7". 
 Line from Spica J under e Corvi and about 11 on. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 121 
 
 CYGNUS (THE SWAN). 
 
 A superb constellation, one of the finest in the northern 
 heavens. Mean R. A., 2oh. 17111. ; Dec., + 41; stars, 
 360. 
 
 a. (Deneb.) R. A., 2oh. 37m. 403.; Dec., + 44 53.2'. 
 
 A beautiful brilliant white star. It has a distant com- 
 panion of mag. 12^, which is beyond the powers of a small 
 telescope. 
 
 ft. (Albireo.) R. A., igh. 26m. 175.; Dec.,+ 27 43.7'. 
 A lovely double, one of the finest in the skies. A 3, topaz 
 yellow ; B 7, sapphire blue, the colors in beautiful con- 
 trast. D., 34.8". 
 
 //. R. A., 2ih. 3901. i2s.; Dec., + 28 15'. A beauti- 
 ful double with a distant companion. A 5, white ; B 6, C 
 7j, both blue. D., AB 3.84", AC 208.74". Distance 
 AB is decreasing. A line from s Cassiopeae through ft 
 Cass., and 32 on, will reach it at a point 19 due N. of e 
 Pegasi. 
 
 o 2 . R. A., 2oh. lorn. ios.; Dec., + 46 24.5'. A wide 
 triple in a small telescope, quadruple in anything over 5 
 inches. A 4, orange ; B 7^, C 5^, both cerulean blue. 
 D., AB 106.8", AC 337.8". C is o 1 Cygni. This group is 
 5 from Deneb, on a line to y Draconis. 
 
 X*. R. A., i9h. 44m. 385.; Dec., + 33 9-7'- An ex- 
 traordinary variable, with distant companion. It is of a 
 splendid red color, and varies from mag. 5 (4, according 
 to some observers) to invisibility in 4o6d. It takes about 
 3^ months in increasing from minimum to maximum 
 brightness, and the same time in decreasing ; after which 
 it remains invisible for about six months. It is 8 from ft 
 on a line to v. 
 
122 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 X 1 . R. A., iph. 42111. 155.; Dec., + 33 28.8'. A fine 
 double. A 5, golden yellow; B 9, pale blue. D., 25.7". 
 It is but 2m. 235. W. of the above object, and 9.1' nearer 
 the N. 
 
 16. R. A., iph. 38m. 545.; Dec., 4- 50 16.2'. A fine 
 double. A 6J, B 7, both fawn-color. D., 37.9". It is 
 ij from z on line to a. 
 
 61. R. A., 2ih. im. 575.; Dec., + 38 12.5'. A famous 
 and most interesting double, perhaps a binary. A 5 J, B 6, 
 both yellow ; the smaller one of deeper tint. D., 20.1". 
 This was the first star the distance of which was deter- 
 mined. This was accomplished in 1838, by the illustri- 
 ous Bessel of Konigsberg. He ascertained its parallax to 
 be 0.3 136". A more recent determination is that of 
 Auwers 0.56 ; and there is but one star which exhibits 
 a larger parallax, namely, a Centauri. The distance of 
 6 1 Cygni is 366,400 times the distance of the earth from 
 the sun, and its light occupies six years in traversing this 
 stupendous interval. A line from Vega through y Cygni 
 and 10 on, reaches a point ij- due S. of 61 ; and a line 
 from a through v and prolonged 3^ strikes it. 
 
 R. R. A., i9h. 33m. 525.; Dec., + 49 57'. A red star, 
 varying in 425 days from mag. 6 to 14. It is 12 from 
 a towards y Draconis. 
 
 6 B. R. A., i9h. 9m. i6s.; Dec., + 49 37.9'. A pretty 
 double. A 6, B 7, both yellow. D., 9.8". 3^ due S. 
 
 Of H. 
 
 149 P. XIX. R. A., i9h. 23m. 435. ; Dec., + 36 
 
 18.4'. A very elegant double. A 8J, white ; B 9, pale 
 
 blue. D., 7.2". 8 from /? on line towards H. 
 
 276 P. XIX. R. A., i9h. 4im. 375.; Dec., + 35 
 
 49.4'. A neat double. A 8, B 8J, both white. D., 
 
 14.7". Line from Polaris through 6 and 91 on. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 123 
 
 278 P. XIX. R. A., iQh. 4im. 445.; Dec., + 34 
 44.6'. A fine double. A 6, straw color ; B 8, smalt 
 blue ; colors beautiful. D., 38.2". About i S. of last 
 object. 
 
 2708 2. R. A., 2oh. 34m. 305.; Dec., + 38 15.4'. A 
 double star. A 4*, yellow ; B pj, blue. D., 24.6", and 
 increasing. Line from a Cephei through a Cyg., and 
 7 on. 
 
 1470 H. R. A., iph. 59m.; Dec., + 38 o'. A beautiful 
 double. A 8J, pale clear red ; B 91, intense blue. D., 
 23.8". A line from a to fi passes about i due S. of it, 
 ioj from the former. 
 
 2048 h. (H. 4511.) R. A., i 9 h. 37m. 255.; Dec., + 39 
 56.1'. A rich cluster of very minute stars of mag. n to 
 15. 5 from d on line to /?. 
 
 20 $[ VIII. (H. 4559.) R. A., 2oh. 7m. 223.; Dec., 
 + 26 9.6'. A large and rich but loose cluster of stars from 
 mag. 6 to ii. Line from j3 Cassiopese through y Cyg. 
 and 1 8 on. 
 
 8 33 VII. (H.459I.) R. A.,2oh. 2 9 m. 575.; Dec., + 27 
 56.2'. A large, bright and rich cluster. Line from e 
 Cassiopese, the northernmost star of the Chair, through 
 Cyg. and 6J on. 
 
 2107 h. (H. 4645.) R. A., 2ih. 7m. i8s. ; Dec., 
 + 45 13.8'. An extended and pretty rich cluster of prin- 
 cipally loth mag. stars. Between a and p, 6 from 
 former, and due E. 
 
 39 M. (H. 4681.) R. A., 2ih. 28m. 155.; Dec., + 47 
 56.9'. A brilliant cluster in a rich vicinity. Line from /3 
 through y and 14 on. 
 
 56 l^ VIII. (H. 4575.) R. A., 2oh. 19111. 95.; Dec., 
 + 40 25.6'. A beautiful group of stars, mag. 10 to 12. 
 It is from y on line to a. 
 
124 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 DELPHINUS (THE DOLPHIN). 
 
 A little constellation which offers a very rich region for 
 sweeping. Mean R. A., 2oh. 2om.; Dec., + 12; stars, 
 
 y. R. A., 2oh. 4im. 335.; Dec., + 15 43.9'. A 
 beautiful double. A 4, yellow ; B 7, light emerald, but 
 appears to vary in color, since it is described as yellow, 
 green, and blue, by various observers. D., 11.3". This 
 constellation may be recognized by the little square of 
 stars between Aquila and Pegasus ; y is the easternmost 
 of these. 
 
 2703 2. R. A., 2oh. 31111. 405.; Dec., + 14 21'. A 
 pretty triple. A white, B yellowish, C white, all mag. 7^. 
 D., AB 25.2", AC 69.2", BC 59.7". This object is but 9 ' 
 N. and 43" W. of ft, the southernmost and largest star in 
 the square. 
 
 DRACO (THE DRAGON). 
 
 A winding and convoluted constellation, always above 
 the horizon. Mean R. A., i5h. 55m.; Dec., + 70; stars, 
 255- 
 
 a. (Thuban.) R. A., i4h. im. 245.; Dec., + 64 54.1'. 
 A star with a distant companion. A 3^, pale yellow ; B 8, 
 dusky. Difference of R. A., 23.95. This star is suspected 
 of variability, having been rated as of magnitudes from 2 
 to 4. 
 
 #. R. A., i9h. 1 2m. 315.; Dec., + 67 28'. A star with 
 a distant companion. A 3, deep yellow ; B 9^, pale red. 
 D, IS4-7". 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 125 
 
 i. R. A., i5h. 22m. 295.; Dec., + 59 21.1'. A bright 
 star with distant companion. A 3, orange tint ; B 9, pale 
 yellow. D., 254.6". Other stars in field. Line from 
 Polaris through y Urs. Min. and 1 2 J on. 
 
 o. R. A., i8h. 49m. 345.; Dec., + 59 15.3'. A neat 
 double in a fine field. A 5, orange yellow ; B lilac. D., 
 31.8". A line from ft Herculis through y Drac. will pass 
 within J of it, io from the latter. 
 
 ip\ R. A., lyh. 43m. 545. ; Dec., + 72 12.5'. A neat 
 double. A 5^, B 6, both pearly white. D., 30.9". 8 
 from 6 on line to y Urs. Min. 
 
 40. R. A., i8h. 8m. i6s. ; Dec., + 79 59'. A fine 
 double. A 5^, B 6, both white. D., 20.1". 10 from 
 Polaris on line to y. 
 
 2278 2. R. A., i8h. om. 585.; Dec., + 56 26'. A 
 triple star. A 7^, B 8, both white ; C 8J. D., AB 38.1", 
 AC 5.9". ij S. and a little E. from , the 3d mag. star 
 6 N. of y. 
 
 190 B. R. A., i8h. 3im. 265. ; Dec., + 52 15.7'. A 
 beautiful double. A 6, very yellow ; B 8-J-, very blue. 
 Colors very fine. D., 25.4". 13 from Vega on line to 
 the Pole. 
 
 2573 2. R. A., i 9 h. 3 8m. 303.; Dec., + 60 15.3'. 
 A double star. A 6, white; B 9, blue. D., 18.1". 
 Exactly on line from a Lyrse to Polaris, and 22 from the 
 former. 
 
 256 # I. (H. 3671.) R. A., i 3 h. 45. 33*. ; Dec., 
 + 60 44.8'. An irregularly round nebula, brightening 
 towards the centre. 11 from rj Urs. Maj. on line to- 
 wards Polaris. 
 
 102 M. (H. 4064.) R. A., ish. 6m. 555. ; Dec., + 57 
 25.6'. A small and rather faint nebula. 13 from 77 Urs. 
 Maj. on line to B, Drac. 
 
126 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 37 ]J[ IV. (H. 4373.) R. A., i 7 h. 5 8m. 35 s. ; Dec., 
 + 66 38'. A planetary nebula. It will prove difficult in 
 a small telescope, but should be tried. Like other plane- 
 tary nebulae it somewhat resembles a star out of focus. A 
 line from d to rj will pass within less than i S. of it, 7 
 from the former. 
 
 EQUULEUS (THE LITTLE HORSE). 
 
 A diminutive asterism which offers, outside of its good 
 low-power fields, but one object for our examination. 
 Mean R. A., 2ih. lorn. ; Dec., + 5 ; stars, 36. 
 
 355, 356 P. XX. R. A., 2oh. 47 m. i8s. ; Dec., + 6 
 55'. A pair of stars, both mag. 8-J-, both white. D., 
 40.3". 15 from Altair on a line from 6 Pegasi. 
 
 ERIDANUS (THE RIVER). 
 
 An extensive southern constellation, a large proportion 
 of which is below the horizon in England and the United 
 States. Mean R. A. of portion visible in latitude 40, 3h. 
 4om. ; Dec., - 25 ; stars, 343. 
 
 32. R. A., 3h. 48m. 465. ; Dec., - 3 16.8'. A splen- 
 did double. A 5, topaz yellow ; B 7, sea-green or blue. 
 D., 6.7". Secchi calls the colors magnifici, superbi. Line 
 from Sirius through Rigel, and 19 on. 
 
 39. R. A., 4h. 9m. los. ; Dec., 10 31.6'. A delicate 
 but not difficult double. A 5, yellow; B n, deep blue. 
 D., 6.3". This star is known as A in some catalogues 
 and maps. Line from Orionis (lowest in belt), through 
 ft Erid. and 14} on. 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 127 
 
 55. R. A., 4h. 38m. i8s. ; Dec., - 8 59.9'. A beauti- 
 ful double. Both mag. y-J, both yellowish white. D., g". 
 Line from Orionis through ft Erid. and 7^ on. 
 
 62. R. A., 4h. 5om. 595.; Dec., 5 20.8'. A wide 
 double. A 6, white ; B 8, lilac. D., 63.8". Line from 
 upper part of Orion's sword-cluster through ft Erid. and 
 3 on. 
 
 /. R. A., 3 h. 44m. 335.; Dec., 37 57.8'. A superb 
 double. A 5, B 5^. D., 8.5". Line from upper part of 
 Orion's sword-cluster through Rigel and 50 on. 
 
 2569 h. (H. 748.) R. A., 3h. 34m. 205.; Dec., - 35 
 48.9'. A globular cluster, nebulous in small telescope. A 
 line from 6 Orionis through ft Erid. and 52 on will pass 
 within 2 E. of this cluster. 
 
 26 ] IV. (H. 826.) R. A., 4h. 9m. ios.; Dec., 13 
 1.3'. A planetary nebula, very faint in small telescope, 
 and not bearing high powers. Lassell pronounces it the 
 most interesting and extraordinary object of the kind 
 which he had ever seen. Line from s Orionis to ft Erid. 
 and 15 on. It is 4^ from y E. and a little N. 
 
 GEMINI (THE TWINS). 
 
 A highly interesting and important constellation. Mean 
 R. A., 7h.; Dec., + 22 ; stars, 190. 
 
 a. (Castor.) R. A., yh. 27m. 353.; Dec., + 32 7.8'. 
 A splendid binary star, the largest and finest in the north- 
 ern hemisphere. A 3, bright white ; B 3^, pale white. 
 D., 5.64". The period of revolution of this magnificent 
 system is, according to Thiele, 996 years. 
 
 ft. (Pollux.) R. A., 7 h. 3 8m. 355.; Dec., + 28 17.5'. 
 A multiple star of 6 components. Our observer will see 
 
123 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 it as a coarse triple. A 2, orange tinge ; D 9^ ; E 9. D., 
 AD 206.3", AE 229.2". 
 
 y. R. A., 6h. 3im. 2is.; Dec., + 16 29.5'. A bright 
 white star of mag. 3, in a beautiful field. 
 
 e. R. A., 6h. 3701. ios.; Dec., + 25 14.3'. A star with 
 distant companion. A 3, yellow ; B 9^, cerulean blue. 
 D., 1 10.6". Rather difficult. 
 
 K. R. A., yh. 37m. 485.; Dec., + 24 39.7'. A very 
 delicate and beautiful but difficult double. A 4, orange ; 
 B 10, pale blue. D., 6.39". 4 due S. of Pollux. 
 
 R. R. A., 7h. om.; Dec., + 22 53'. An extraordinary 
 variable, from 6^ to 12^ mag. Period 371 days. Ac- 
 cording to Hind, this star is blue, red, and yellow, by 
 turns. It yielded to Secchi a wonderful spectrum with 
 bright lines. 10 from Pollux on line to y. 
 
 15. R. A., 6h. 2im. 135.; Dec., -f- 20 51.5'. A fine 
 double. A 6, flushed white ; B 8, bluish. D., 31". 5 
 from y on line to yu. 
 
 20. R. A., 6h. 25m. 528.; Dec., + 17 51.4'. A beau- 
 tiful double in a fine field. A 8, topaz yellow ; B 8^, 
 cerulean blue. D., 20". 2 from y on a line to 77. 
 
 38. R. A., 6h. 48m. ^265.; Dec., + 13 19.1'. A very 
 fine double. A 5^, light yellow ; B 8, purple ; colors 
 very marked. D., 6.3". 5^ from y on line to Procyon. 
 
 135 Birm. R. A., 6h. 4m. 35.; Dec., -j- 26 2.3'. A 
 fine ruby star of mag. 7j or 8. Line from y i W. of //, 
 and 5 further. 
 
 540 South. R. A., 7h. 2im. 6s.; Dec., + 22 22.2'. 
 A beautiful pair. A 7^, red ; B 9, blue. D., 35.6". 2 
 due E. of d. 
 
 1108 2. R. A., yh. 26m. 155. ; Dec., + 23 7.8". A 
 beautiful double. A 7, yellowish white ; B 9, bluish. 
 D., 11.5". Line from y to d and 3 on. 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. I2Q 
 
 1035 2. R. A. (1880), yh. 4m.; Dec., + 22 29'. A 
 beautiful, double. Both mag. 7^, both yellowish. D., 
 8.5". Line from y to and 2 on. 
 
 26 J$ VIII. (H. 1325.) R. A., sh. 54m. 245.; Dec., 
 4- 23 17.9'. A rather large cluster of 40 or 50 stars from 
 mag. 8 to 15. 2j W. and a little N. of 77, is a 5th mag. 
 star, i. The cluster is i J due W. of this star. 
 
 35 M. (H. 1360.) R. A., 6h. 2m. 45.; Dec., + 24 
 21.2'. A gorgeous cluster of stars from mag. 9 to 16. 
 Smyth says : " From the small stars being inclined to 
 form curves of three or four, and often with a large one 
 at the root of the curve, it somewhat reminds one of the 
 bursting of a sky-rocket." Lassell says : " A marvel- 
 lously striking object. No one can see it for the first 
 time without an exclamation. . . . Nothing but a 
 sight of the object itself can convey an idea of its exquis- 
 ite beauty." 3^ from jw on line to ft Tauri. 
 
 40 $[ VIII. (H. 1490.) R. A., 7h. om. 395.; Dec., 
 + 27 21.7'. A large scattered cluster. 7 from Castor 
 on line to Betelgeuse. 
 
 45 IJU IV. (H. 1532.) R. A., yh. 22m. 415.; Dec., 
 + 21 8.1'. A star enveloped in a nebulous atmosphere 
 about 25" in diameter ; a most remarkable object. The 
 central star is of mag. 7 J. Line from s to <5 and 2 on. 
 
 ii JL VIII. (H. 1534.) R. A., yh. 2 2 m. 535.; Dec., 
 + 13 59.6'. A compressed cluster of very minute stars. 
 9 from Procyon on line to $ Gem. 
 
 HERCULES. 
 
 A large and very interesting constellation, although not 
 conspicuous to the naked eye. Mean R. A., i6h. 50111.; 
 Dec., + 32; stars, 451. 
 
 9 
 
130 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 a. (Ras Algethi.) R. A., lyh. gm. 385.; Dec., + 14 
 30.9'. A splendid double. A 3^, orange ; B 5^, emerald 
 or bluish green. D., 4.7". Smyth calls this a lovely ob- 
 ject, one of the finest in the heavens. 
 
 d. R. A., iyh. lorn. 315.; Dec., + 24 58.3'. A beauti- 
 ful double. A 4, greenish white ; B 8^, grape red. D., 
 18.1". Due N. of a 11. 
 
 H\ R. A., i6h. 3m. 6s.; Dec., + 17 20.6'. A very 
 pretty double. A 5^, light yellow ; B 7, pale garnet. D., 
 29.8". Line from ft Lyrae to ft Here, and 7 on. 
 
 p. R. A., i7h. i9m. 535.; Dec., + 37 14.9'. A beauti- 
 ful double. A 4, bluish white ; B 5j, pale emerald. D., 
 3.89". 2 from n on line to Wega. 
 
 36-37. R. A., i6h. 35m. 75.; Dec., + 4 26.1'. A pair 
 of blue stars of mag. 6J and y. D., 69.8". It is 16 W. 
 of ft Ophiuci, just S. of a line from it to e Serpentis. 
 
 95. R. A., i7h. 56m. 505. ; Dec., + 21 35.8'. A lovely 
 double. A 5^, light apple-green ; B 6, cherry red. D., 
 6.1". There is much difference of opinion as to the 
 colors of these stars ; Macdonnell pronounced both 
 golden-yellow. About I2-J from a Ophiuci on line 
 to ft Lyrae. 
 
 100. R. A., i8h. 3m. 245. ; Dec., + 26 4.8'. A neat 
 double. Both mag. 7, both pale white. D., 14.1". i2-J 
 from ft Lyrae on line to a Herculis. 
 
 2104 2. R. A., i6h. 44m. 455. ; Dec., + 36 6.5'. A 
 very pretty double. A 6-J-, white ; B 8, ash-colored. 
 D., 5.9". 4 from 2, on line to ft Draconis. 
 
 2007 ^. R. A. (1880), i6h. im. ; Dec., + 13 39'. A 
 very fine pair. A 6J, yellowish-white ; B 8, white. D., 
 32". Line from ft through y and 7 on. 
 
 2087 ^. R. A. (1880), i6h. 38m. ; Dec., + 23 51'. 
 An exquisite little double. Both mag, 8, both white. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 131 
 
 D., 5.7". Line from a Serpentis through ft Here, and 4 
 on. Just S. and a little E. of this is 
 
 2 5 N. (H. 4234.) R. A., i6h. 39m. 515.; Dec., 
 + 24 o'. A small pale-blue planetary nebula which bears 
 magnifying well. Its disk is about 8" in diameter, but 
 ill-defined. 
 
 13 M. (H. 4230-) R. A., i6h. 37m. 455. ; Dec., + 36 
 39.9'. A gorgeous cluster, one of the most magnificent 
 objects in the heavens. It blazes toward the centre and 
 has numerous outliers. It was discovered by Halley, and 
 is sometimes called H alley's nebula. It is faintly visible 
 to the naked eye ; and " under telescopic aid," says Olm- 
 stead, " it reveals its glories in a form truly exciting to the 
 beholder." Dr. Nichol, more enthusiastic, says : " Per- 
 haps no one ever saw it for the first time through a tele- 
 scope without uttering a shout of wonder." It is almost 
 on a line (a little W.) between 77 and <?, 3^ from the for- 
 mer ; and 7 from a on line to Bootis. 
 
 92 M. (H. 4294.) R. A., lyh. i3m. 465.; Dec., + 43 
 15.1'. A globular cluster, very luminous in centre; a 
 splendid object. 16^ W. and a little S. from ex Lyrae 
 is a 3d mag., which is n Herculis. 92 M. is 7 from it on 
 line to Polaris. 
 
 HYDRA (THE WATER-SNAKE). 
 
 A long winding constellation stretching through more 
 than six hours of right ascension. Mean R. A., nh. 
 26m. ; Dec., 17 ; stars, 370. 
 
 a. (Al-fard, the Solitary, or Cor Hydras.) R. A., 9 h. 
 22m. us. ; Dec., 8 10.9'. A star with a difficult dis- 
 
132 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 tant companion. A 2, but suspected of variability, orange 
 tint ; B 10, pale-green. D., 281.2". 
 
 T\ R. A., ph. 23m. 343. ; Dec., 2 17.2'. A wide 
 double. A 5^, flushed white ; B 8^, lilac. (Colors ac- 
 cording to Webb, pale-white, dusky.) D., 66.2". 6 due 
 N. of a. 
 
 R. R. A., i3h. 23m. 425.; Dec., 22 42.7'. A 
 remarkable variable. Its period is 436 days, and appears 
 to be diminishing. Its extreme magnitudes during visi- 
 bility are 4 and 10. It is of a pale orange-yellow tint, 
 and has a distant greenish 8th mag. companion. D., 
 138.7". 13^ from ft Corvi on line to d Scorpionis, and 
 12 S. and i E. of Spica. 
 
 10. R. A., i4h. 39m. 395.; Dec., 24 58.4'. A very 
 beautiful double. A 5-}, pale orange ; B 7^, violet tint. 
 D,, 9". Line ^from 6 Scorpii (the 3d mag. star 2 W. 
 and N. of Antares) through y Scorpii and 4^ on. 
 
 313 Birm. R. A. (1880), 13!!. 42m.; Dec., 27 46'. 
 A very fine ruby star ; mag. 6^. Line from d Scorp. to 
 y Scorp. and 18^ on. 
 
 108 P. VIII. R. A., 8h. 3om. is.; Dec., + 7 0.5'. A 
 fine double. A 6, pale yellow ; B 7, rose-tint. D., 10.6". 
 A line from Procyon to Regulus passes i N. of this 
 object at a distance of 13^ from the former. 
 
 27 T$ IV. (H. 2102.) R. A., loh. 19111. 255.; Dec., 
 17 35.6'. A fine planetary nebula, bearing magnifying 
 well. Smyth compares it to Jupiter in size and equable 
 light. Noble suggests that it resembles a ghost of Jupi- 
 ter. It is of a pale bluish tint. Line from ft Corvi to e 
 Corvi and 26 on. 2 S. and a little W. from ju. 
 
 68 M. (H. 3128.) R. A., i 2 h. 33m. 345.; Dec., 26 
 7.6'. A pale nebula 3' broad and 4' long. 3^ S. and a 
 little E. from ft Corvi. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 133 
 
 LACERTA (THE LIZARD). 
 
 A small constellation formed by Hevelius. Mean R. 
 A., 22h. ipm. ; Dec., + 52 ; stars, 60. 
 
 a. R. A., 22h. 26m. 445.; Dec., + 49 43'. A star 
 given here only for the noble field in which it is situated. 
 Line from y Cassiopeae to ft Cass. and 17 on. 
 
 S\ R. A., 22h. 3om. 585.; Dec., + 39 3.9'. A quad- 
 ruple star which will be double only in a small telescope. 
 Both 6J, both white. The other components are of mag. 
 10 and ii. D., AB 22.3". Line from y Cygni to v Cyg. 
 and 19 on. 
 
 65 P. XXII. R. A., 22h. 1 4m. 6s.; Dec., + 37 13'. A 
 neat double. A 6J, pale white ; B 9, livid. D., 15.4'. 
 Line from ft Lyrse to y Cygni and 24 on. It closely fol- 
 lows i Lacertae, a 5th mag. star. 
 
 75 m VIII. (H. 4773.) R. A., 22 h. urn. 575.; Dec., 
 + 49 19.9'. A fine cluster, quickly followed by a beau- 
 tiful field. The cluster is about 16' long. Line from 
 Cassiopeae through /3 Cass. and 17 on. 
 
 LEO (THE LION). 
 
 A noble constellation, one of the most striking in the 
 northern hemisphere. Mean R. A., loh. 25m.; Dec., 
 + 20 ; stars, 337. 
 
 a. (Regulus.) R. A., loh. 2m. 305.; Dec., + 12 30.3'. 
 A fine star with a distant companion. A i, flushed white ; 
 B 8J, pale purple. D., 177". Decidedly difficult. 
 
 /?. (Denebola.) R. A., nh. 4301. 275.; Dec., + 15 
 
134 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 11.2'. A bright star with a very distant companion. A 
 2^, bluish ; B 8, dull red. D., 282". Other stars in 
 field. 
 
 y. (Al Gieba.) R. A., loh. i3m. 545.; Dec., + 20 
 23.8'. A splendid double ; according to Struve, the finest 
 in the northern sky. A 2, bright orange ; B 4, greenish 
 yellow. D., 3.61", and increasing. 
 
 6. R. A., Qh. 26m. 45.; Dec., + 10 12.1'. A neat 
 but difficult double. A 6, pale rose tint ; B 9^, pur- 
 ple. D., 36.8". Carry a line from /? ij S. of a and 9 
 on. 
 
 83. R. A., nh. 2im. 133.; Dec., + 3 36.7'. A pretty 
 double. A 8, silvery white ; B 9, pale rose tint. D., 
 29.5". It closely precedes (a little N.) r Leon., to find 
 which draw a line from y Virginis through ft Virg. and 
 5| further. 
 
 90. R. A., nh. 28m. 595.; Dec., + 17 24.4'. A fine 
 triple. A 6, silvery white ; B 7 J, purplish ; C 9j, pale 
 red. D., AB 3.5", AC 63.3". AB probably form a binary 
 system. Line from d Virginis through /? Leon., and 4^ 
 on. 
 
 R. R. A., 9h. 4im. 395.; Dec., + n 56.5'. A superb 
 vivid red star, varying in 312 days from mag. 5 to 10. 
 Hind says : " It is one of the most fiery-looking variables 
 on our list fiery in every stage from maximum to mini- 
 mum, and is really a fine telescopic object in a dark sky, 
 about the time of greatest brilliancy, when its color forms 
 a striking contrast with the steady white light of the 6th 
 magnitude, a little to the N." A line from a to Procyon 
 will pass within S. of this star, 5^ from a. 
 
 1434 2. R. A. (1880), loh. 2im.; Dec., -f 18 41'. 
 A very pretty double. Both 8^ (Struve), both orange. 
 D., 6.1". 2| from y on line to d Corvi. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 135 
 
 95 M. (H. 2184.) R. A., loh. 38m. ios.; Dec., + 12 
 16.3'. A lucid round white nebula. It is 8| due E. of 
 a. About J E. and somewhat N. of this, follows another 
 round but paler nebula. (96 M., H. 2194.) 
 
 17 1$ I. (H. 2203.) R. A., loh. 42m. is.; Dec., 
 + 13 9.4'. A round nebula brightening towards the cen- 
 tre. It is | N. a little E. from last object. 
 
 18 JL I. (H. 2207.) R. A., loh. 42m. 285.; Dec., 
 + 13 12.3'. A faint round nebula, forming a pair with the 
 last object. 
 
 13 13 I. (H. 2301.) R. A., nh. om. ios.; Dec., +0 
 33.5. A pale white, well-defined elongated nebula. A line 
 from y Virginis carried | under rj Virg. and 18 on will 
 reach this object. 
 
 66 M. (H. 2377.) R. A., nh. i4m. 225.; Dec., + 13 
 34.9'. A large faint elongated nebula. 735. from it 
 towards the W. is another of similar shape, but smaller. 
 This is 65 M., H. 2373. They are less than i S. of a 
 line from fi to a, 7^ from /?. 
 
 LEO MINOR (THE LESSER LION). 
 
 A small constellation of little importance, formed by 
 Hevelius. Mean R. A., roh. 2om.; Dec., + 38 ; stars, 
 96. 
 
 86 W I. (H. 2104.) R. A., loh. 2im. 6s.; Dec., +29 
 4'. An oval nebula with central nucleus. Line from a 
 i J W. of y, and 8 on. 
 
 87 ip I. (H. 2274.) R. A., loh. 54m. 128. ; Dec., + 
 29 34'. A large orbicular nebula. 6 from v Urs. Maj. 
 on line to Regulus. 
 
136 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 LEPUS (THE HARE). 
 
 A small southern constellation, poor to the eye, but 
 containing several very interesting objects. Mean R. 
 A., 5h. 32m. ; Dec., 20 ; stars, 66. 
 
 a. (Arneb.) R. A., 5h. 27m. 525. ; Dec., 17 54.2'. 
 A not easy double. A 3^, pale yellow ; B 9^, gray. D., 
 
 35.6". 
 
 y. R. A., 5h. 4om. ; Dec., 22 20'. A beautiful 
 pair, A 4, light yellow, B 6-J-, pale garnet. D., 92.9". 
 
 R. R. A., 4 h. 54m. 363. ; Dec., 14 58.2'. Hind's 
 celebrated " Crimson Star." A superb object. Says Mr. 
 Hind : " It is of the most intense crimson, resembling a 
 blood-drop on the black ground of the sky ; as regards 
 depth of color, no other star visible in these latitudes 
 could be compared to it." Line from 6 Orionis to Rigel, 
 and 7^ on. 
 
 875 2. R. A., 6h. 7m. ; Dec., 13 7'. A pretty 
 double. A 8.7, red ; B 9.8, very green. D., 6". 5f 
 from ft Can. Maj. on line to 2, Orionis. 
 
 79 M. (H. 1 1 12.) R. A., 5h. 19111. 535. ; Dec., 24 
 36.9'. A stellar nebula blazing towards the centre, and 
 with a milky white tinge. A line from a to ft and 4 on 
 will pass within less than i E. of this object. 
 
 LIBRA (THE BALANCE). 
 
 A rather inconspicuous zodiacal constellation. Mean 
 R. A., i5h. 8m. ; Dec., 13 ; stars, 180. 
 
 a. (Kiffa Australis.) R. A., ,14!!. 44m. 475; Dec., 
 15 35'. A wide but fine pair. A 3, pale yellow ; B 
 6, light gray. D., 230.8." 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 137 
 
 ft. (Kiffa Borealis.) R. A., 15)1. nm. 55. ; Dec., 8 
 58.6'. A very beautiful pale green star, the color of 
 which, as Webb remarks, is very unusual among con- 
 spicuous stars. And he adds : " Deep green, like deep 
 blue, is unknown to the naked eye." 
 
 i. R. A., i5h. 5m. 535. ; Dec., 19 22.4'. A wide but 
 rather difficult pair. A 5^, pale yellow ; B 9^, purple. 
 D-, 57-5"' 13 due W. of ft Scorpionis. 
 
 62 P. XIV. R. A., i4h. i6m. 493. ; Dec., 17 15.5'. 
 A fine double. Both 8, both silvery white. D., 5.4". 
 Line from ft Virginis to Spica and 16 on. 
 
 1962 2. R. A., 150, 32m. 435. ; Dec., 8 26'. A 
 striking double. Both 6^, both white, or yellow accord- 
 ing to Franks. D., u.8". Line from Scorpionis to ft 
 Scorp. and 13 on. 6 from jn Serpentis on line to y 
 Scorp. 
 
 212 P. XIV. R. A., i4h. 5om. 555. ; Dec., 20 
 53.2'. A pretty double. A 6, straw color ; B 8, orpi- 
 ment yellow. D., 15.1". A line from y Scorp. to a Lib. 
 will pass within E. of this star, 4^ from the former. 
 
 5 M. (H. 4083.) R. A., i 5 h. 1 2 m. 575. ; Dec., + 2 
 30.1'. A splendid cluster of minute stars, greatly com- 
 pressed in the centre, and more than 7' or 8' in diameter. 
 " A noble mass," says Smyth, " refreshing to the senses 
 after searching for faint objects." 8-J from a Serpentis 
 on line to ft Corvi. 
 
 LYNX. 
 
 A large modern constellation formed by Hevelius. It 
 contains little that is within the power of a small tele- 
 scope. Mean R. A., 7h. 37m. ; Dec., + 50 ; stars, 149. 
 
 19. R. A., 7h. i3m. 535. ; Dec., + 55 28.6'. A wide 
 but pretty triple. A 7, white ; B and C both 8, both plum- 
 
138 THE AMATEUR TELE$COPIST*S HANDBOOK. 
 
 colored. D., AB 14.3", AC 215.2". 27 from Polaris 
 on line to Pollux. 
 
 40. R. A., ph. 1301. 515. ; Dec., + 34 49.5'. A fine 
 deep orange-red star of mag. 4. This is sometimes 
 known as a. Line from 2, Urs. Maj. to y Urs. Maj. 
 and 33 on. 
 
 41. R. A., ph. 2im. 275. ; Dec., + 46 5.3'. A wide 
 double. A 6, B 8J, both bluish. D., 81.6". 6 from A 
 Urs. Maj. on line to H Urs. Maj. 
 
 LYRA (THE LYRE). 
 
 A small but splendid constellation, perhaps the finest, 
 in proportion to its size, of them all. Mean R. A., i8h. 
 3om.; Dec., + 36; stars, 166. 
 
 a. (Wega, Vega or Lyra.) R. A., i8h. 3301. 138. ; 
 Dec., + 38 40.9". A grand pale-sapphire star of the 
 first magnitude, one of the most splendid in the heavens. 
 It has a minute blue companion of mag. n, distant 48.1", 
 but although it has been seen by some observers with 
 less than 2 inches, I doubt if the average eye can see 
 it with anything under 3^ inches. 
 
 /?. (Sheliak.) R. A., i8h. 46m. is. ; Dec., + 33 14.1'. 
 A variable star ranging from mag. 3^ to 4^ in i2d. 2ih. 
 53m. It has 4 companions of which our observer may 
 see 3. B 8, pale gray ; D 8J, faint yellow ; E 9, lilac ; 
 D., AB 45.6", AD 66.5" AE 85.6". A is called white by 
 Smyth, yellow by Webb. 
 
 6. R. A., i8h. 49m. 525. ; Dec., + 36 50.3'. A star 
 in a splendid low-power field, with a distant companion 
 known as (T. A 4, orange ; B 5, white. 
 
 . R. A., i8h. 40111. 415. ; Dec., + 39 33.2'. A won- 
 
THE AMATEUR TELESCOPlST's HANDBOOK. 139 
 
 derful multiple system. Under the slightest optical aid 
 an opera-glass is quite sufficient this star is seen dou- 
 ble ; and with a high power each of the components is 
 seen to be double. Between them are 3 minute stars, 
 only one of which, of mag. 9^, will be seen with a small 
 telescope. Each of the minute pairs is a binary ; the com- 
 ponents of f 1 having a period of about 2,000 years, those 
 of s* a period of about 1,000 years, and possibly both 
 pairs revolve around their common centre of gravity in 
 something less than 1,000,000 years. D., e 1 f 2 , 207"; 
 components of t 1 , 3.16"; of 2 , 2.58". Magnitudes, f 1 5, 
 * 6J. Less than 2 E, and somewhat N. of a. 
 
 <?. R. A., i8h. 4om. 595.; Dec., + 37 29.4'. A fine 
 double. A 5, topaz ; B 5^, greenish. 2 from ct, forming 
 with it and a nearly equilateral triangle. D., 44.1". 
 
 rj. R. A., i9h. lorn, is.; Dec., +38 57.5' A neat 
 double. A 5, sky-blue ; B 9, violet tint. A is yellow, ac- 
 cording to Knott. D., 28.5". ii of a line from a to y 
 Cygni, and 6 from the former. 
 
 2372 2. R. A., i8h. 38m. us. Dec., +34 38.2'. 
 A double star. A 7, white ; B 9, clear blue. D., 24.9". 
 3 from a on line to 8, Aquilae. 
 
 56 B. R. A., i8h. 39m. 415.; Dec., + 44 49.4'. A 
 double star. A 7, yellow ; B 9, bluish white. D., 26.3". 
 6 from e on line to Polaris. 
 
 91 B. R. A., i8h. 5om. 515.; Dec., + 33 49.7'. A 
 beautiful double (really triple). A 6, yellow ; B 7, blue. 
 D., 45.3". Knott calls this "a charming miniature of ft 
 Cygni ; the colors very fine." Less than i from /3 on 
 line to 6, the star just S. of 77. 
 
 2470 2. R. A., i9h. 4m. 445. ; Dec., -f 34 35.5'. A 
 pretty double. A 7, B 9, both white. D., 13.3". 2^ 
 from y on line to 6. 
 
140 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 57 M. (H. 4447.) R. A., i8h. 4901. 285. ; Dec., + 
 3 2 53-6'. A wonderful annular nebula ; the only one of 
 the few in the heavens that is within the reach of a small 
 telescope. It is a somewhat elliptical ring of light, about 
 80" in diameter. According to Sir W. Herschel, it is dis- 
 tant from us 950 times as far as Sirius ! It was consid- 
 ered that Secchi had resolved this nebula into stars, but 
 Muggins finds only a gaseous spectrum. About J the 
 distance between /3 and y. 
 
 56 M. (H. 4485.) R. A., i9h. i2m. i6s.; Dec., + 
 29 59.3'. A globular cluster of very minute stars, nebu- 
 lous in a small telescope. It is in a splendid field. 5^ 
 from ft on line to /3 Cygni. 
 
 MONOCEROS (THE UNICORN). 
 
 A large modern constellation devised by Bartschius, 
 Kepler's son-in-law. Mean R. A., 7h. 28m. ; Dec., 10 ; 
 stars, 220. 
 
 5. R. A., 6h. 9m. 305. ; Dec., 6 14.4'. A fine orange 
 star of mag. 4^. 7^ from H Orionis on line to Procyon. 
 
 8. R. A., 6h. 1 7m. 565. ; Dec., + 4 38.8'. A fine 
 double in a glorious low-power field. A 4^, golden yel- 
 low ; B 7, lilac. D., 13.9". Line from Aldebaran 
 through A, Orionis (the north star of the 3 in the head), 
 and 13 on. Nearly 8 from a Orionis. 
 
 10. R. A., 6h. 22m. 315. ; Dec., 4 41.9'. A wide 
 double in an elegant group. A 6, pale yellow ; B 9, 
 orange. D., 76.9". It is nearly (a trifle S.) on a line 
 from H Orionis to Procyon, nj from the former. 
 
 11. R. A., 6h. 23m. 295.; Dec., 6 57.7'. An ele- 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 141 
 
 gant triple, requiring high powers. Sir W. Herschel 
 called it one of the most beautiful sights in the heavens. 
 A 6J, B 7, C 8, all white. D., AB 7.2", AC 9.6", BC 2.7". 
 Line from Aldebaran to Bellatrix and 2oJ on. 
 
 104 P. VI. R. A., 6h. 22m. 45. ; Dec., + o 31'. A 
 wide double. A 7^-, topaz yellow ; B 8-J, plum tinge. D., 
 66.1". B is itself double in powerful telescopes. "A 
 low-power field includes 77, a fine 6th mag. yellow star, 
 with this pair np and another s p ; a noble spectacle." 
 (Webb.) 20 from Procyon on line to /3 Eridani. 
 
 116 P. VII. R. A., 7h. 22m. 428.; Dec., 11 20'. 
 A double star ; in reality a delicate quintuple. A 7, 
 yellow ; B 9, violet. D., 23.4". Line from A Eridani 
 (the 4th mag. star to the right of Rigel) to H Orionis, 
 and 24^ on. 
 
 2 ] VII. (H "1424.) R. A., 6h. 2501. 45. ; Dec., + 5 
 1.3'. A beautiful, brilliant cluster of stars from mag. 7 to 
 14, the latter running in rays. Line from ft Eridani, 
 midway between lowest and middle stars of Orion's belt, 
 and i4j on. 
 
 3 1$ VIII. (H. 1429.) R. A., 6h. 28m. 465. ; Dec., 
 + 8 26.5.' A large and rich cluster, but little condensed. 
 Line from Bellatrix to Betelgeuse and 10 on. 
 
 27 # V. (H. 1440.) R. A., 6h. 34 m. 555. ; Dec., + 9 
 59.8'. A magnificent stellar field, containing 15, a green- 
 ish 6th mag. star. Line from y Orionis through a Or. 
 and nf on ; the object will be found i due N. of the 
 point so reached. 
 
 27 13 VI. (H. 1465.) R. A., 6h. 46m. 75. ; Dec., 
 o 35.3'. A bright cluster, divided into 3 rich groups 
 resembling 3 arms of a cross. Line from Aldebaran 
 through Betelgeuse and 15! on. 
 
 50 M, (H. 1483.) R. A., 6h. 57m. 415. Dec., 8 
 
142 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 10.7'. A superb cluster, irregularly round and very rich. 
 A line from Sirius to Procyon will pass i S. E. of this 
 cluster, 9-J from Sirius. 
 
 34 ]p VIII. (H. 1506.) R. A., yh. gm. 205. ; Dec., 
 10 5.7'. A rich field, containing an oval mass of stars 
 and a fine double star. (1052 ^.) Mags. 8 and 8-J-, both 
 white. Line from a Leporis to 6 Can. Maj. and 5^ on. 
 
 22 3 VI. (H. 1637.) R. A., 8h. 8m. 8s. ; Dec., - 
 5 28'. A rich splashy cluster containing a splendid 
 group. Its alignment is very difficult, but it may be 
 picked up thus : Carry a line from ft Can. Min. to 
 Procyon and i ij on ; from the point thus reached, line 
 due S. 2|. 
 
 OPHIUCUS (THE SERPENT-BEARER). 
 
 A large and, to the naked eye, rather dull constellation. 
 Mean R. A., i6h. 50111. ; Dec., 3 ; stars, 289. 
 
 36. R. A., i7h. 8m. 345. ; Dec., 26 25.3'. A fine 
 double. A 4j, ruddy ; B 6J, pale yellow. D., 5". nj 
 from Antares on line to ff Sagit. 
 
 39. R. A., i7h. nm. 1 8s. ; Dec., 24 9.9'. A very 
 beautiful double. A 5^, pale orange ; B 7^, blue. D., 
 10.7". 17 from A Sagit. on line to d Scorp. 
 
 53. R. A., i7h. 2901. 235. ; Dec., + 9 39.8'. A wide 
 double. A 6, B 8, both bluish. D., 41.2". 3 due S. 
 of a. 
 
 6 1. R. A., i7h. 39m. 35. ; Dec., + 2 37.6'. A pretty 
 double. A 6|, B 7, both white. D., 20.2." i W. of y, 
 and 2 S. of /?. 
 
 67. R. A., i7h. 55m. 8s. ; Dec., -f 2 56.2'. A wide 
 double. A 4, straw-color ; B 8, purple. D., 54.7". A 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 143 
 
 little W. and S. of this is a fine orange star which is 422 
 Birm. Line from 61 through y and 3 on. 
 
 124 B. R. A., i;h. im. los. ; Dec., i 30.2'. A 
 double star. A 7, B 9, both white. D., 20.3". 16 from 
 a on line to a Scorp. 
 
 12 M. (H. 4238.) R. A., i6h. 4im. 315. ; Dec., i 
 45.9'. A fine rich globular cluster, condensed towards 
 centre. Nebulous in small telescope. 9 from 2, on line 
 to H. 
 
 10 M. (H. 4256.) R. A., i6h. 5im. 225. ; Dec., 3 
 56.8'. A rich globular cluster, blazing towards centre. 
 About 8' in diameter. It is more easily resolved than 12 
 M. Of a lucid white tint. Line from a Scorp. to 8, Oph. 
 and 9 on. 
 
 19 M. (H. 4264.) R. A., i6h. 55m. 485. ; Dec., 26 
 6.9'. A fine globular cluster, nebulous in small telescope, 
 of a creamy white tint. 8 from Antares on line to a 
 Sagit. 
 
 9 M. (H. 4287.) R. A., i7h. i2m. 375. ; Dec., - 18 
 24.2'. A globular cluster of excessively minute stars, 
 brightening towards centre. Nebulous in small telescope. 
 14^ from Antares on line to 6 Aquilse. 
 
 14 M. (H. 43 I 5-) R - A -> !7h. 3 im - 5 s - ; D ec., 3 
 11.2'. A nebulous-looking cluster, rather faint in small 
 telescope, but very interesting. 8 from ft on line to 9. 
 
 23 M. (H. 4346.) R. A., i7h. 5om. 285. ; Dec., 18 
 58.9'. An " elegant sprinkling " of telescopic stars ; a 
 grand low-power field. Line from a Sagit. to ju Sagit. 
 and 4^ on. 
 
 IT JJ[ VI. (H. 4268.) R. A., i6h. 57m. 445. ; Dec., 
 24 36.3'. A globular cluster of small stars, con- 
 densed towards centre. 8 from Antares on line to ff 
 Sagit. 
 
144 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 ORION. 
 
 The most gloriously beautiful of all the constellations ; 
 splendid alike to the eye and to the telescope. Mean R. 
 A., 5h. 26m. ; Dec., o ; stars, 304. 
 
 a. (Betelgeuse.) R. A., 5h. 39111. 145. ; Dec., + 7 
 23'. A brilliant star which is probably variable to a 
 slight degree, but never falls below the ist magnitude. 
 Its color is extremely striking. " A most beautiful and 
 brilliant gem ! singularly beautiful in color, a rich topaz ; 
 in hue and brilliancy different from any other star I 
 have seen. " (Lassell.) " Look at a and fi alternately ; 
 even a small telescope will show the beauty of the con- 
 trast." (Webb.) 
 
 /?. (Rigel.) R. A., 5h. pm. 155. ; Dec., 8 19.9'. 
 A splendid star with a small blue companion of mag. 9. 
 D., 9.5". Rigel itself has a blue tint which Knott pro- 
 nounces one of the finest shades among the stars. The 
 comes is a celebrated test-object ; some abnormally keen- 
 eyed observers, like Dawes and Burnham, have seen it 
 with less than 2 inches, but 2-J inches, in most favorable 
 weather, is the very lowest aperture, I think, that may 
 ever be expected to show this little star to the average 
 eye. 
 
 d. R. A., 5h. 26m. 235.; Dec., o 22.9'. A very 
 beautiful double, though wide. A 2, brilliant white ; B 7, 
 violet. D., 52.8". 
 
 e. R. A., 5h. 3om. 385. ; Dec., i 16.4'. A star with 
 a difficult distant companion. A 2^, bright white ; B 10, 
 pale blue. D., 179.9". 
 
 2. R. A., 5h. 35m. 128.; Dec., 2 0.2'. A fine but 
 difficult triple. A 3, topaz yellow, and very bright for its 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 145 
 
 magnitude; B 6J, light purple; C 10, gray. D., AB 2.61", 
 AC 57.1". B is the star to which Struve applied what 
 Chambers calls his " terrible adjective," olivaceasubrubi- 
 cunda. 
 
 \. R. A., 5h. 29111. 55.; Dec., + 9 51.5'. An elegant 
 double. A 4, pale white ; B 6, violet (yellow and blue, 
 Dembowski}. D., 4.3". This is the northernmost of the 
 3 little stars in the head. 
 
 p. R. A., 5h. ym. 325.; Dec., + 2 43.7'. A beautiful 
 double. A 5, orange ; B 9, smalt blue ; colors very de- 
 cided. D., 7.1." This is 5| N. W. of #, and the stars of 
 the belt point almost upon it a little above. 
 
 ff. R. A., 5h. 33m. 35.; Dec., 2 38'. An extraor- 
 dinary multiple system ; a double-quadruple star with 2 
 stars between the systems. A small telescope will show 
 it as a triple. A 4, bright white ; B 8, bluish ; C 7, grape 
 red. D., AB 12.7", AC 41. 6". Less than i S.W. of <?. 
 
 23. R. A., 5h. 17111. 35.; Dec., + 3 26.3'. A neat 
 double. A 5, white ; B 7, pale gray. D., 31.1". 3 from 
 y on line to ft. 
 
 31. R. A., 5h. 23m. 595.; Dec., i 10.8'. A lovely 
 golden star of mag. 5^. It has a very difficult blue 
 comes of mag. n. D., 12.7". i^ from d on line to ft. 
 
 96 Birm. R. A., 4h. 59m. 435.; Dec., + i 1.6'. A 
 splendid fiery red star, mag. 7. Line from Sirius through 
 rj and 6 on. 
 
 589 2. R. A. (1880), 4h. 38m. ; Dec., + 5 5'. A 
 beautiful double, possibly binary. Both 8, both yellowish 
 white. D., 4.5". Line from /3 to ft Erid. and 12 on. 
 
 278 P. IV. R. A., 4h. 56m. i8s.; Dec., + i 26.8'. A 
 neat double. A 8J, silvery white ; B 9, pale blue. D., 
 13.8". Line from /3 Can. Maj. to u Or. and 16 on. 
 About i W. and somewhat N. of 96 Birm. 
 
 10 
 
146 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 42 M. (H. 1179.) R. A. (of 6), 5h. 29111. 525.; Dec., 
 5 27.7. The Great Nebula in Orion. An overwhelm- 
 ing object : a vast tract of nebulous light, faintly visible 
 to the naked eye, and growing in awful impressiveness 
 with every increase of optical aid. In the angle of the 
 strange gap in the nebula which is sometimes called the 
 Fish's Mouth, lies 0, a multiple star, usually called the 
 Trapezium, from the figure formed by its principal stars. 
 It is readily seen with powers of from 50 upwards. The 
 components of the Trapezium are of mags. 6, 7, 7^, and 8 
 In addition to these, contains two most minute stars of 
 mag. 10 J and 12, which cannot be seen except with 
 higher powers and larger apertures than the amateur can 
 generally command. There are even other stars in or 
 near the Trapezium, but they seem not to belong to the 
 system. 
 
 78 M. (H. 1267.) R. A., 5h. 4im. 6s. ; Dec. +0 2.1'. 
 Two stars in a " wispy " nebula. Mags. 8J and 9. The 
 object resembles a binuclear nebula. Faint, but most 
 interesting. 7^ from a on line to ft Leporis. 
 
 PEGASUS. 
 
 An extensive constellation, the interest of which, how- 
 ever, can hardly be considered proportional to its size. 
 Mean R. A., 2zh. 50111. ; Dec., + 20 ; stars, 393. 
 
 f. (Enif.) R. A., 2ih. 38m. 475. ; Dec., + 9 22.2'. A 
 star with a distant companion. A 2 J, yellow ; B 9, violet. 
 D., 140.2". 
 
 i. R. A., 2ih. 1 7m. os. ; Dec., + 19 20'. A pretty 
 but not easy double. A 4, pale orange ; B 9, purplish. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 147 
 
 D., 37.1". Line from Altair to ft Delphini (the brightest 
 in that asterism), and 12^ on. 
 
 3. R. A., 2ih. 32111. 145. ; Dec., + 6 7.5'. A neat 
 double. A 6, white ; B 8, pale blue. D., 39.3". A pretty 
 little double in field, 8" apart. Line from e Peg. to J3 
 Aquarii ; at a point 3^ from e, draw a line about J W., 
 and it will reach this star. 
 
 33. R. A., 22h. i8m. 2is. ; Dec., + 20 17.5'. A dou- 
 ble star. A 6, yellowish ; B 8, pale gray. D., 63.3". 
 Line from fi Capric. to e and 14^ on. 
 
 2848 2. R. A., 2ih. 52m. 305.; Dec., + 5 25'. A 
 pretty double. A 8, white ; B _8|-, yellowish or red. D., 
 10.6". 5^ from s on line to y Aquar. 
 
 306 P. XXII. R. A., 23h. 2m. 125. ; Dec., + 32 
 13.8'. A fine double. A 7, bright white ; B 8^, sapphire 
 blue. D., 8.6". 14 from a Androm. on line to 2, Cyg. 
 
 216 P. XXIII. R. A., 23!!. 47m. 215. ; Dec., + 11 
 18.8'. A neat double. Both 8J, both silvery white. D., 
 18.7". 5J exactly S. W. of y. 
 
 15 M. (H. 4670.) R. A., 2ih. 24m. 345. ; Dec., + 
 11 40.3'. A splendid globular cluster, nebulous in small 
 telescope, but resolvable with a comparatively moderate 
 aperture. There are some stars in the field, but Smyth 
 remarks that the globular mass strikes the senses as 
 being almost infinitely beyond these apparent comites. 
 Line from 6 to f, and 4^ on. 
 
 PERSEUS. 
 
 A brilliant and beautiful constellation, situated in a 
 very fine portion of the Milky Way. Mean R. A., 3!!. 
 1 6m. ; Dec., + 50 ; stars, 196. 
 
148 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 P. (Algol, the Demon.) R. A., 3h. im. 25.; Dec., + 
 40 31.9'. A wonderful variable, the most conspicuous 
 of all the regularly variable stars. Its period is 2d. 
 2oh. 49m., and its range from mag. 2 to 4. Its time of 
 decrease and increase together occupy about 7 hours, 
 and it remains at minimum but 18 minutes. Line from 
 fi Aurigae through Capella and 24 on ; or it may be 
 recognized as the first conspicuous star 9^ S. a little W. 
 from a. 
 
 rj. R. A., 2h. 42m. 405. ; Dec., 4- 55 26.3'. A beauti- 
 ful double. A 5, orange ; B 8J, smalt blue ; colors clearly 
 contrasted. D., 28.4". Line from a to y and 3 on. 
 
 58. R. A., 4h. 29m. 25. ; Dec., + 41 2.3'. A neat 
 triple. A 5^, orange tint ; B 71, greenish ; C 9, lilac. 
 D., BC 1 1.8". 8J from Capella on line to . 
 
 220 P. II. R. A., 2h. 53m. 25. ; Dec., + 51 54.9'. 
 A neat double. A 6, silvery white ; B 8, sapphire blue. 
 D., 1 2.1". About 2 S. a little W. from y. 
 
 104 B. R. A., 2h. 54m. 445. ; Dec., +31 58.6'. A 
 pretty double. A 7, yellow ; B 8J, blue. D., 8.8". 23 
 from fi Androm. on line to Aldebaran. 
 
 76 M. (H. 385.) R. A., ih. 35m. 25. ; Dec., + 51 1.8'. 
 An oval, pearly white nebula, binuclear, and pronounced 
 by Webb a curious miniature of the Dumb-bell nebula. 
 It is close to and N. of <p, the 4th mag. star 9 from y 
 Androm. on line to y Cassiop. 
 
 33 ] VI. (H. 512.) R. A., 2h. nm. 205.; Dec., + 
 56 38.5'. A gorgeous cluster, followed closely by 34 IJt 
 VI. (H. 521), another equally splendid mass, the two 
 groups forming what is usually called the cluster in the 
 sword-handle of Perseus. One of the central stars in the 
 second group is of a fine ruby color. The two clusters 
 are in the same field with a low power, and form one of 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 149 
 
 the most magnificent telescopic objects in the heavens. 
 Just S. of a line from 6 Cassiop. to y Pers., and midway 
 between them. 
 
 34 M. (H. 584.) R. A., 2h. 34m. 575,; Dec., + 42 
 15.7'. A beautiful scattered cluster. "A very grand low- 
 power field, one of the finest objects of its class." (Webb.) 
 Just N. of a line from y Androm. to e Pers., and 7j from 
 the former. 
 
 25 J$ VI. (H. 658.) R. A., 3h. 7m. 265.; Dec., 4- 
 46 49.4'. A beautiful compressed cluster, called by 
 Smyth "an elegant sprinkle." "A low power shows a 
 very faint large cloud of minute stars beautifully bordered 
 by a foreshortened pentagon of larger ones." (Webb.) 
 Midway between a and K the 4th mag. star S. and W. 
 of a. 
 
 88 ]$ VIII. (H. 717.) R. A., 3 h. 2 4 m. 365.; Dec., + 
 36 56.7'. A large cluster of minute stars ; about 60 in 
 the group. 6 from Algol on line to Aldebaran. 
 
 61 ] VII. (H. 820.) R. A., 4h. 6m. 525. ; Dec., + 50 
 57.5'. A rich cluster, the larger stars arranged in curves. 
 11 from y on line to Capella. 
 
 PISCES (THE FISHES). 
 
 A large but particularly dull-looking constellation. 
 Mean R. A., oh. 25m.; Dec., + 20; stars, 257. 
 
 a. R. A., ih. 56m. 2 is.; Dec., + 2 14'. A close 
 double. A 5, B 6. The most extraordinary differences 
 of opinion exist as to the colors of the components. 
 Smyth calls them pale green and blue ; Dawes, both 
 white, etc. D., 3.08" and decreasing. 
 
150 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 3. R. A., ih. ym. 595.; Dec., + 6 43.7'. A fine 
 double. A 6, silver white ; B 8, pale gray. D., 24.7". 
 Line from rj Erid. through Mira and 19 on. 
 
 ip 1 . R. A., oh. 59m. 475.; Dec., + 20 53'. A fine 
 double. Both 5^, both silvery white. D., 29.8". Line 
 from S Cassiop. to /? Androm. and 14 on. 
 
 35. R. A., oh. 9m. i8s. ; Dec., + 8 12.6'. A fine 
 double. A 6, pale white; B 8, violet tint. D., n.6". 
 Line from a Androm. to y Pegasi and 5 j on. 
 
 38. R. A., oh. nm. 445.; Dec., + 8 15.8'. An elegant 
 double. A ;J, light yellow ; B 8, flushed white. D., 4.5". 
 " Those sage astrologers who dubbed Pisces a most ma- 
 lignant sign, ought to have contemplated this beautiful 
 object ; had this been done, every notion of stellar un- 
 propitiousness and malevolence must have vanished." 
 (Smyth.) f nearly due E. of last object. 
 
 51. R. A., oh. 26m. 435.; Dec., + 6 20'. A fine but 
 difficult double. A 6|, pearl white ; B 9, lilac tint. D., 
 28.4". 9^ from y Peg. on line to ?/ Ceti. 
 
 55. R. A., oh. 34m. 8s. ; Dec., + 20 50.7'. A very 
 beautiful double. A 6, orange ; B 9, deep blue, but 
 rather faint. A fine specimen of opposed colors. D., 
 6.34." Line from a Cassiop. to d Androm. and 9 on. 
 
 65. R. A., oh. 43m. 583. ; Dec., + 27 6.7'. A fine, 
 close double. A 6, B 7, both pale yellow. D., 4.3". 
 Some observers call both mag. 6. About 8J from a 
 Androm. on line to fi Arietis. 
 
 77. R. A., ih. om. 8s. ; Dec., + 4 19.3'. A fine 
 double. A 7^, pale white ; B 8, pale lilac. D., 33.3". 
 Line from 3, Androm. to 8 Pise, and 3 on. 
 
 100. R. A., ih. 29m. is. ; Dec., + 11 59.8'. A pretty 
 double. A 7, white ; B 8, pale gray. D., 16.4". Line 
 from Mira through a and 12 on. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 151 
 
 251 P. O. R. A., oh. 53m. 455. ; Dec., o 11.4'. 
 A neat double. A 8, pale orange ; B 9, clear blue. D., 
 20". ioj from 0' Ceti on line to y Pegasi. 
 
 PlSCIS AUSTRALIS (THE SOUTHERN FlSH). 
 
 A small constellation, important only for its beautiful 
 lucida. Mean R. A., 22h. 15111. ; Dec., 29 ; stars, 77. 
 
 a. (Fomalhaut.) R. A., 22h. 5im. 345. ; Dec., 30 
 12.3'. A fine reddish star with a very distant dusky blue 
 companion of mag. 9^. Difference of R. A., 4.83. 
 
 SAGITTA (THE ARROW). 
 
 A diminutive constellation in the Milky Way. Mean 
 R. A., i 9 h. 33m. ; Dec., + 18 30' ; stars, 34. 
 
 . R. A., 19!!. 32m. i8s. ; Dec., + 16 12.9'. A star 
 with distant companion. A 6, pale white ; B 8, light 
 blue. D., 92.2". 6^ from y Aquilse on line to Wega. 
 
 d. R. A., 2oh. 5m. 55. ; Dec., + 20 35.2'. A triple. 
 A 7, pale topaz ; B 9, gray ; C 8, pearly yellow. B is 
 very difficult. D., AB 11.5", AC 76.4". Line from ft 
 Ceph. to y Cyg. and 19 on. 
 
 X. R. A., i9h. 55m. 55. ; Dec., + 17 13'. A 6th mag. 
 orange star, the lucida of a beautiful group containing a 
 smaller very red star, and a pretty little loth mag. pair. 
 7j from y Aquilse on line to Cyg.' 
 
 SAGITTARIUS (THE ARCHER). 
 
 A large and important zodiacal constellation. Mean 
 R. A., i9h. 1501. ; Dec., - 44 ; stars, 339. 
 
152 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 /*'. R. A., i8h. 7m. los. ; Dec., 21 5.2'. A triple 
 star. A 3-J, pale yellow ; B 9^, blue ; C 10, reddish. D., 
 AB 48.3", AC 50.1". It is the 4th mag. star 6 N.W. 
 of A. 
 
 294 P. XVII. R. A., iyh. 52111. os. ; Dec., 30 14.9'. 
 A fine double. A 6, B 71, both strong yellow. D., 5.6". 
 i| due W. of y. 
 
 8028 Lacaille. R. A., 19!!. 5m. 325. ; Dec., 34 
 0.5'. A pretty double. Both mag. 7. D., 15". A line 
 from to , carried 4 on, reaches a point i due W. of 
 this star. 
 
 5112 h*. R. A., i9h. i7m. 45.; Dec., 18 12'. A 
 striking triple (really quintuple). All 3 of mag. 8. D., 
 AB 23.5", AC 20." E. of, and very close to, p and p 2 , the 
 close naked-eye pair 4^ N. E. from ?r. 
 
 505. Birm. R. A., 19!!. 28m. os.; Dec., 16 36.8'. A 
 fine ruby star of mag. 6^. A line from d to TT, and 7^ on, 
 reaches a point less than i due S. of this star. 
 
 3702 a. h. (H. 4324.) R. A., i7h. 38m. 295.; Dec., 
 33 3^.5'. A cluster of tolerable richness, the components 
 ranging from mag. 8 to 12. 7| S.W. of y. 
 
 13 W VI. (H. 4335.) R. A., i;h. 43m. 35$.; Dec., 
 30 10.9'. A cluster composed principally of i2th mag. 
 stars. A curious rift in the middle. 3^ nearly due W. 
 (a trifle N.) from y. 
 
 7 M. (H. 4340.) R. A., i7h. 46m. 405.; Dec., 34 
 47.2'. A cluster of stars from mag. 7 to 12. Rich but 
 rather straggling. A line from d Scorp. to Antares, and 
 22^ on, will pass about i S. of the cluster. 
 
 8 M. (H. 4361.) R. A., iyh. 57m. 8s.; Dec., -24 
 22.6'. A singular and splendid nebula. " In a large 
 field we find a bright coarse triple star, followed by a 
 resolvable luminous mass, including two stars or starry 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 153 
 
 centres, and then by a loose bright cluster enclosed by 
 several stars." (Webb.) Sir J. Herschel remarks that 
 the cluster seems to be superposed upon the nebula. 
 5f almost exactly N. of y. 
 
 21 M. (11.4367.) R.A.,i7h. 5801. 2S.; Dec.,-22 30.8'. 
 A coarse cluster of telescopic stars in a rich galaxy region. 
 i| due N. of last object. 
 
 3729 h. (H. 4376.) R. A., i8h. om. 3 6s.; Dec.,-2 3 
 14'. A large rich cluster. 2^ S.W. of //'. 
 
 30 W VII. (H. 4388.) R. A., i8h. 6m. 8s.; Dec., 
 21 35.8'. "A curious large undefined cloud of loth 
 mag. stars, requiring low power and steady gazing." 
 (Webb.) | S.W. of p\ 
 
 SCORPIO (THE SCORPION). 
 
 A superb constellation, the most brilliant of the 
 Southern asterisms that are visible in our latitudes. 
 Mean R. A., i6h. 355.; Dec., 33 ; stars, 200. 
 
 a. (Antares.) R. A., i6h. 22m. 398.; Dec., 26 11.2'. 
 A splendid star of mag. i, of a fiery red color. " It is a 
 grand telescopic object. Its tint, however, is not uniform. 
 To me the disc appears yellow, with flashes of deep crim- 
 son, alternating with a less proportion of fine green." 
 (Webb.) It has a minute green companion of mag. 7, 
 D., 3.02", which is a noted and severe test. It has been 
 seen by Warner with 2f inches, but Proctor doubts whether 
 anything under four inches may be expected to show it. 
 The possessor of a 3-inch may try it under favorable 
 atmospheric conditions, especially if he happens to live 
 S. of latitude 40. 
 
154 THE AMATEUR TELESCOPIST S HANDBOOK. 
 
 /?. (Acrab.) R. A., i5h. 59111. 25.; Dec., 19 30.2'. 
 A fine double. A 2, pale white ; B 5^, lilac tinge. D., 
 
 3.5" 
 
 v. R. A., i6h. 5m. 365.; Dec., 19 10.3'. A multiple 
 star ; double in a small telescope. A 4, bright white ; 
 B 7, pale lilac. D., 40.8". if E. and a little N. from ft. 
 
 So M. (H. 4173.) R. A., i6h. iom. 263.; Dec.,-22 
 43.2'. A compressed globular cluster of extremely minute 
 stars. It has a nebulous or cometary aspect. Sir W. 
 Herschel called it the richest and most condensed mass of 
 stars which the firmament can offer to the contemplation 
 of astronomers ; a description which the worker with a 
 small telescope will hardly appreciate. Near its centre, 
 but probably between us and it, is the variable T, which 
 in 1860 had risen to the 7th magnitude, entirely over- 
 powering the cluster, but in less than a month faded out, 
 and has not (1893) been seen distinctly since. Exactly 
 midway between a and ft. 
 
 4 M. (R 4183.) R. A., i6h. i6m. 535.; Dec., -26 
 14.8'. A pale, elongated cluster, nebulous in small tele- 
 scopes, about 2.5' long, and brightening towards the cen- 
 tre. i| W. of Antares ; i S. a trifle E. from <?. 
 
 62 M. (H. 4261.) R. A., i6h. 54m. 145.; Dec., 29 
 55.4'. A fine resolvable nebula, brightening towards the 
 centre. Line from a to a and 8| on. 
 
 SCUTUM SOBIESKI. See CLYPEUS SOBIESKI. 
 
 SERPENS (THE SERPENT). 
 
 A long winding constellation of little interest ; really a 
 part of Ophiucus. Mean R. A., i6h. 4501.; Dec., o ; 
 stars, 187. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 155 
 
 6. R. A., i8h. 50111. 455.; Dec., + 4 3.4'. A beautiful 
 double. A 4^, pale yellow ; B 5, golden yellow. D. 
 21.6". A noble pair. It lies i| S. of a line from d 
 Aquilae to a Ophiuci, and 7^ from 8 Aq. 
 
 72 ] VIII. (H. 4410.) R. A. (1880), i8h. 22m.; 
 Dec., + 6 29'. A very fine cluster of small stars. " Be- 
 tween it and 6, nearer the former, is a beautiful large cloud 
 of stars, chiefly 8 and 9 mag. , a nearer part, apparently, 
 of the Galaxy ; visible to naked eye, and requiring a large 
 field." (Webb.) 7 from 6, almost on a line (a trifle S.) 
 from 6 to a Oph. a Here, and a Oph. point almost to it. 
 
 SEXTANS (THE SEXTANT). 
 
 A small and unimportant asterism formed by Hevelius. 
 Mean R. A., 9h. 56m.; Dec. + 2 ; stars, 112. 
 
 163 1I I. (H. 2008.) R. A., 9h. 59m. 455.; Dec., - 7 
 11.3'. An elongated bright nebula which is possibly vari- 
 able, since Sir J. Herschel could scarcely see it with six 
 inches of his 2o-foot reflector, while it is now readily visi- 
 ble, and bears magnifying unusually well, in a 2^-inch re- 
 fractor. Extend a line 9^ due E. from a Hydrae ; and 
 from this point, a line i^ due N. 
 
 TAURUS (THE BULL). 
 
 A brilliant and beautiful constellation, of the highest 
 interest both to the naked eye and the telescope. Mean 
 R. A., 4h. 3m.; Dec., + 16 ; stars, 394. 
 
 a. (Aldebaran.) R. A., 4h. 29m. 363.; Dec, + 16 
 17.5'. A noble red star, pale rose tint, with a blue tele- 
 
156 THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 scopic companion. D., 113.9". The companion is a dif- 
 ficult object, but a 3j-inch will show it. 
 
 1 B\ R. A., 4h. 22m. i6s.; Dec., + 15 43.1'. A 
 beautiful wide pair. A 5, pearly white ; B 51, yellowish. 
 D., 337.3". These stars are next to a in the V that marks 
 the Hyades. 
 
 x 1 H\ R. A., 4h. i8m. 385.; Dec., + 22 2.5'. A fine 
 wide pair. A 5^, yellowish white ; B 6J, white. D., 339". 
 7 from a just E. of a line from a to Pers. 
 
 r. R. A., 4h. 35m. 385.; Dec., + 22 44.8'. A star 
 with rather distant companion. A 5, bluish white ; B 8, 
 lilac. D., 63.3". 7 from a on line to Capella. 
 
 q>. R. A., 4h. 13111. 343.; Dec., -f 27 5.4'. A beauti- 
 ful wide double. A 6, light red ; B 8J, cerulean blue. 
 D., 53.7". A red 7th mag. star follows it by 15'. i2*from 
 a on line to a Pers. 
 
 X. R. A., 4h. 1501. 535.; Dec., + 25 22.2'. A pretty 
 double. A 6, white ; B 8, pale blue. D., 19.2". 2 S. a 
 trifle E. from cp. 
 
 62. R. A., 4h. 1 7m. 225.; Dec., -f 24 2.8'. A pretty 
 double. A 7, silver white ; B 8J, purple. D., 28.9". In 
 a fine field. The last two objects point directly to it, x ly- 
 ing almost midway between cp and 62. 
 
 118. R. A., 5h. 22m. 305.; Dec., + 25 3.6'. An ele- 
 gant double. A 7, white ; B 7^, pale blue. D., 5.1". 
 3 from ft, a trifle W. of a line from fi to . 
 
 257 P. IV. R. A., 4h. 52m. 445.; Dec., + 14 22.5'. 
 A beautiful wide triple. A 7, white ; B 8, cerulean blue ; 
 C 10, purple. D., AB 39", AC 54.2". Line from Betel- 
 geuse through the triangle of Orion's head and ioj on. 
 
 548 ^. R. A. (1880), 4h. 2im.; Dec., + 30 6'. A 
 pretty double. A 6, yellowish ; B 8, bluish. D., 14.2". 
 8 from r, on line to a Pers. 
 
THE AMATEUR TELESCOPIST S HANDBOOK. 157 
 
 785 2. R. A. (1880), sh. 3 9 m.; Dec., f 25 53'. A 
 pretty double. A 6J, white ; B 7$, bluish white. D., 
 13.8". 5 from /?, a trifle E. from a line from ft to rf 
 Gemin. 
 
 4 ] VII. (H. 1030.) R. A., 50. 5m. 428.; Dec., 
 + 1 6 34.1'. A very rich cluster of small stars, more than 
 filling the field. 8J- from a on line to y Gemin. 
 
 i M. (H. 1157.) R. A., 5h. 27m. 515.; Dec., + 21 
 56.6'. A pearly white nebula, the famous " Crab Nebula " 
 of Lord Rosse, and notable as the object the accidental 
 discovery of which by M. Messier in 1758 led to the forma- 
 tion by him of the first catalogue of nebulae. It is of an 
 oval form, and bears some resemblance to a telescopic 
 comet, for which it has more than once been mistaken. 
 i^ from 8, on line to 2, Pers. 
 
 THE PLEIADES. Mean R. A., 3h. 38m.; Dec., 4- 23 
 30'. This famous and most beautiful group of stars forms 
 a glorious low-power field. Tempel's Nebula, a faint tri- 
 angular haze involving Merope, the star s p Alcyone the 
 brightest of the group, should be looked for, as it has been 
 seen with less than 2 inches. It is suspected, with good 
 reason, of variability. 
 
 THE HYADES. Mean R. A., 4h. 2om.; Dec., + 15. 
 This group gives several fine low-power fields. It is about 
 2 W. and a little S. of a. 
 
 TRIANGULUM (THE TRIANGLE.) 
 
 A small but ancient asterism. Mean R. A., 2h. 5m.; 
 Dec., + 32 ; stars, 33. 
 
 i. R. A., 2h. 5m. 598. ; Dec., + 29 47.2'. A most 
 beautiful double. A 5 J- , topaz yellow ; B 7, green. D., 
 
158 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 3.86". Colors very fine. Line from y Androm. to ft 
 Triang. and 4j on. 
 
 28 B. R. A., 2h. 8m. 175.; Dec., + 29 53.1'. A pretty 
 double. Both 8, both very white. D., 6.41". 2m. i8s. 
 E. of z, and 6' towards the N. 
 
 33 M. (H. 352.) R. A., ih. 27m. 385.; Dec., 4- 30 
 6.8'. A large faint nebula, only visible with low powers. 
 It is about 30' in diameter. One of the Rosse " spirals." 
 Line from e Pers. to /? Triang. and 8^- on. 
 
 URSA MAJOR (THE GREATER BEAR). 
 
 A grand constellation, one of the noblest of them all. 
 Mean R. A., loh. 38m.; Dec., + 56 ; stars, 338. 
 
 a. (Dubhe.) R. A., loh. 56m. 563.; Dec., + 62 20.7'. 
 A bright star with a very distant companion. A i J, yel- 
 low ; B 8, yellow (violet, Webb). D., 380.6". 
 
 ft. (Merak.) R. A., loh. 55m. 125.; Dec., + 56 58.3'. 
 A star with a very distant and difficult companion. A 2, 
 greenish white ; B n, pale gray. D., 245." Others in 
 field. 
 
 d. (Megrez.) R. A., i2h. 9111.585.; Dec., + 57 38.6'. 
 A fine star with a distant companion. A 3, pale yellow ; 
 B 9, ash-colored. A is suspected of being variable between 
 mag. 2 and 4 at a very long period. D., 188. 6". 
 
 . (Mizar.) R. A., 13!!. i9m. 295.; Dec., + 55 30.1'. 
 A splendid double. A 3, brilliant white ; B 5, pale emer- 
 ald. D., 14.57." Alcor, a 5th mag. star n^' from Mizar, 
 forms with it a naked-eye double. 
 
 57. R. A., nh. 23m. 95.; Dec., + 39 56.5'. A beau- 
 
THE AMATEUR TELESCOPIST'S HANDBOOK. 159 
 
 tiful double. A 6, lucid white ; B 9, violet. D., 5.43". 
 7^ from v, a trifle E. of line from v to d. 
 
 1402 2. R. A., 9h. 57m. 315.; Dec., + 56 0.8'. A 
 pretty double. A y, yellow ; B 8J, bluish. D., 23.5". 
 6 from 6 on line to ft. 
 
 1603 2. R. A., i2h. 2m. 385.; Dec., + 56 5'. A neat 
 double. A yj, B 8, both white. D., 22.4". About mid- 
 way between y and d. 
 
 205 1$ I. (H. 1823.) R. A., 9h. 1401. 245.; Dec., + 
 51 28.1'. An elliptical nebula about 4' long, a miniature 
 of the great Andromeda nebula. It is pale white, and 
 nucleated. 2 from 6 on line to i. 
 
 78 13 I. (H. 1909.) R. A., 9h. 4om. 325.; Dec., + 
 7 2 47. 7'. Around nebula. Line from to A. and 9 
 on. 
 
 81 and 82 M. (H. 1949, 1950.) Mean R. A., 9!!. 46m. 
 235.; Dec., + 69 38.8'. The first of these is oval. The 
 other is J S. of 81, and is long and narrow. T; and 
 point to them. 27 from . 
 
 286 ! I. (H. 1982.) R. A., 9h. 53m. 365.; Dec., 
 + 69 16.3'. A round lucid white nebula, brightening 
 towards centre. " There are two lines of three stars each 
 across the field, of which the one preceding the nebula is 
 of the 7th mag. and that following of the loth ; between 
 these the sky is intensely black, and shows the nebula as 
 if floating in awful and illimitable space, at an inconceiv- 
 able distance." if E. and N. of last object. 
 
 46 l V. (H. 2318.) R. A., nh. 4m. 595.; Dec., + 
 56 15.6'. A faint but large and well-defined elon- 
 gated curved nebula. About ij from /? nearly on line 
 to y. 
 
 97 M. (H. 2343.) R. A., nh. 8m. i 9 s.; Dec., + 55 
 36.7'. A wonderful planetary nebula, large and pale, 
 
l6o THE AMATEUR TELESCOPIST'S HANDBOOK. 
 
 about 2 40" in diameter. If this nebula were only as dis- 
 tant from us as 6 1 Cygni, its real diameter would be seven 
 times that of the orbit of Neptune ; but as its distance 
 was actually beyond the gauging powers of Herschel's 
 2o-foot reflector, it must be, according to Sir William's 
 estimate, at least of the pSoth order ; in other words, 980 
 times the distance of Sirius ! Its actual dimensions must 
 be, then, of a character that, in Admiral Smyth's phrase, 
 makes the imagination quail Less than i S.E. of last 
 object. 
 
 J 73 W I- (H. 2600.) R. A., nh. 47m. 125. ; Dec., + 
 37 36.2'. A pale white nebula, brightening towards the 
 middle, of considerable size. Line from Polaris to y and 
 17 on ; then a trifle E. 
 
 43 V. (2841.) R. A., i2h. i3m. 335.; Dec., + 47 
 54.5'. A white oval nebula, better denned at edges than 
 at ends. It has a nucleus in its southern portion. Line 
 from a to y, and yj on. 
 
 URSA MINOR (THE LESSER BEAR). 
 
 A small, but, from its position, highly important 
 constellation. Mean R. A., 15!!. pm.; Dec., + 79 ; 
 stars, 75. 
 
 a. (Polaris.) R. A., ih. i8m. 145.; Dec., + 88 43.3'. 
 The Pole-Star, the most important of all the stars to the 
 inhabitants of our planet. It is a noted double. A 2j, 
 topaz yellow ; B 9^, pale white. D., 18.5". This is a well- 
 known test. It has been seen by some observers with as 
 low as one inch, but Dawes suggests, that, as a general rule, 
 a good 2-inch and a good eye should detect the little star 
 
THE AMATEUR TELESCOPIST's HANDBOOK. l6l 
 
 with the power of 80. The smallest aid that shows it to 
 me is 2 inches with a power of 64. 
 
 VIRGO (THE VIRGIN). 
 
 A noble constellation of great dimensions, and replete 
 with astronomical interest. Mean R. A., 13!!. i6m.; Dec., 
 2 30'; stars, 411. 
 
 a. (Spica.) R. A., 13!!. igm. 245.; Dec., 10 35.2'. 
 A beautiful bright star with a distant telescopic com- 
 panion. A i, brilliant flushed white ; B 10, bluish tinge. 
 D, 359-8". 
 
 y. R. A., i2h. 36m. 55.; Dec., o 50.8'. A splendid 
 and famous binary with a period of about 180 years. Both 
 4, both yellowish. D. (1880), 5.24". This noble pair 
 appeared single to all but the most powerful telescopes 
 in 1836, and has been widening ever since. 
 
 S. R. A. (1880), i3h. 27m.; Dec.,-6 35'. A vivid 
 red variable, ranging in 374 days from mag. 7 J to i2j. 
 It is said to show especially a feature of several vari- 
 ables, a striking twinkling at times, particularly on the 
 point of diminution. (Webb.) 4 from Spica on line to 
 Arcturus. 
 
 32 P. XII. R. A., i2h. i2m. 305.; Dec., 3 20.5'. A 
 fine double. Both 7^ (though some observers rate them 
 as differing by half a magnitude), and both white. D., 
 20.1". 3^ from rj on line to e Corvi. 
 
 196 P. XII. R. A., i2h. 45m. 395.; Dec., 9 44.4'. A 
 very pretty double. A 6J, topaz yellow ; B 9^, lucid pur- 
 ple. D. 32.3". 6| from d on line to d Corvi. 
 
 221 P. XII. R. A., i2h. 49m. 595.; Dec., + 12 5.7'. 
 ii 
 
162 THE AMATEUR TELESCOPIST's HANDBOOK. 
 
 A neat double. A yj, pale white ; B 9, sky blue (reddish, 
 Sadler). D., 29. i". 2 W. a trifle N. from e. 
 
 25 P. XIII. R. A, i3h. 9 m. us.; Dec.,- 10 46,4'. 
 A pretty though wide double. A 7^, B 8J, both bluish. 
 D., 42.4". 2^ W. of a. 
 
 88 M. (H. 3049.) R. A., i2h. 26m. 265.; Dec., + 
 15 1.9'. A long elliptical nebula, y'x ij' in size. Line 
 from a to 6 and i2j on. "This is a wonderfully nebu- 
 lous region, and the diffused matter occupies an extensive 
 space, in which several of the finest objects of Messier 
 and the Herschels will readily be picked up by the keen 
 observer in extraordinary proximity. It will be conven- 
 ient to keep in mind that the situation of the extraordinary 
 conglomerate of nebulae and compressed spherical clusters 
 which crowd the Virgin's left wing and shoulder is pretty 
 well pointed out to the practised naked eye by , d, y, rj 
 and ft Virg. forming a semicircle to the E., whilst due N. 
 of the last-mentioned star, ft Leonis marks the N.W. 
 boundary. Reasoning upon the Herschelian principle, 
 this may reverently be assumed as the thinnest or shallow- 
 est part of our firmament, and the vast laboratory of the 
 segregating mechanism by which compression and insula- 
 tion are ripened in the course of unfathomable ages. The 
 theme, however imaginative, is solemn and sublime." 
 (Smyth.) 
 
 98 M. (H. 2786.) R. A., i2h. 8m. 345.; Dec., + 15 
 30.5' A faint and pale elongated nebula. 6^ nearly due 
 E. (a trifle N.) from ft Leonis. 
 
 87 M. (H. 3035.) R. A., i2h. 25m. 155.; Dec., + 12 
 59.4'. A large, round nebula, brighter at centre, 8^ 
 from s on line to ft Leonis. 
 
 31 J$ I. (H. 3075.) R. A., i2h. 2 8m. 285.; Dec., + 
 8 18.1'. An extended nebula much brighter in centre. 
 
THE AMATEUR TELESCOPIST's HANDBOOK. 163 
 
 Line from a to 6 and 15^ on. There is splendid sweep- 
 ing with a low power all through this nebulous region ; 
 but identification is very difficult, and only a few typical 
 nebulae have been here described. 
 
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