GIFT OF- the estate of Prof. Wnu P. Meyer ASTRONOMY LIBRARY URAJSrOGRAPHY UEANOGEAPHY A BRIEF DESCRIPTION OF THE CONSTELLATIONS VISIBLE IN THE UNITED STATES STAB-MAPS, AND LISTS OF OBJECTS OBSERVABLE WITH A SMALL TELESCOPE BY C. A. YOUNG, PH.D., LL.D. LATE PROFESSOR OF ASTRONOMY IN PRINCETON UNIVERSITY A SUPPLEMENT TO THE AUTHOR'S "ELEMENTS OF ASTRONOMY FOR HIGH SCHOOLS AND ACADEMIES" GINN AND COMPANY BOSTON NEW YORK CHICAGO LONDON ATLANTA DALLAS COLUMBUS SAN FRANCISCO ENTERED AT STATIONERS' HALL COPYRIGHT, 1889, 1897, BY CHARLES A. YOUNG COPYRIGHT, 1917, BY FREDERICK A. YOUNG ALL RIGHTS RESERVED PRINTED IN THE UNITED STATES OF AMERICA 331.8 / Vbe atftenatum l&ttse GINN AND COMPANY . PRO- PRIETORS BOSTON U.S.A. IV D nn /..';7r;-c-;-:oMY LIBRARY PEEPACE. THIS brief description of the constellations was pre- pared, at the suggestion of a number of teachers, as an integral part of the author's "Elements of Astronomy." It has been thought best, however, for various reasons, to put it into such a form that it can be issued separately, and used if desired in connection with the larger " Gen- eral Astronomy," or with any other text-book. Since the Uranography also has to be used more or less in the open air at night, many will probably prefer to have it by itself, so that its use need not involve such an exposure of the rest of the text-book. All references marked Astr. are to the articles of the " Elements of Astronomy." M577279 / ALPHABETICAL LIST OP THE CONSTELLATIONS DE- SCRIBED OR MENTIONED IN THE URANOGRAPHY. ABTICLK ARTICLK Andromeda 16 Hydra . 38 Anser, see Vulpecula . 54 Lacerta . 61 Antinoiis, see Aqulla . 56 Leo . 36 Antlia 45 Leo Minor 37 Aquarius . 63 Lepus ; ; . 27 Aqulla 56 Libra . 44 Argo Navis 34 . Lupus 45 Aries . . . . 19 Lynx , . . .29 Auriga . . 22 Lyra ,. . . ,> 52 Bootes . . v . - 42 Mondceros . . 32 Camelopardalis . . ' 14 Norma : . . ' : 47 Cancer . v . . 35 Ophiudhua .48,49 Canes Venatici . . i 41 Orion '. . .. .24,25 Canis Major . . ! 33 Pegasus '. . . . 62 Canis Minor .' . i 31 Perseus '. . . 21 Capricornus . . . 58 Phoenix . . . 20 Cassiopeia . . ; - 9, 10 Pisces .. . 17 Centaurus . . i . 45 Piscis Australia. 64 Cepheus . . , 11 (Pleiades) , .. 23 Cetus 20 Sagitta 55 Coma Berenices 40 Sagittarius 57 Columba . 28 Scorpio . 46, 47 Corona Borealis 43 Sculptor . 20 Corvus 38 Serpens . 48,49 Crater 38 Serpentarius, see Ophiuchus 48, 49 Cygnus . . 53 Sextans 37 Delphmus . 59 Taurus . . . 23 Draco . 12, 13 Taurus Poniatovii 48 Equiileus . 60 Triangulum 18 Erfdanus . 26 Ursa Major . 5-7 Gemini . . . 30 Ursa Minor 8 Grus 64 Virgo 39 Hercules . . .50,51 Vulpecula. 54 471 URANOGRAPHY. THE GEEEK ALPHABET. Letters. Name. Letters. Name. Letters. Name. A, a, Alpha. I, t, Iota. P, p, ^, Kho. B, 0, Beta. K, K, Kappa. 2, , ^, Phi. Z, t Zeta. H, fe Xi. X, x , CM. H, 17, Eta. O, o, Omicron. *, $, Psi. , 0, #, Theta. n, TT, Pi. O, w, Omega. 472 URANOGRAPHY, OR A DESCRIPTION OF THE CONSTELLATIONS. 1. A general knowledge of the constellations sufficient to enable one to recognize readily the more conspicuous stars and their principal configurations, is a very desirable accomplish- ment, and not difficult to attain. It requires of course the actual study of the sky for a number of evenings in different parts of the year ; and the study of the sky itself must be supplemented by continual reference to a celestial globe or star-map, in order to identify the stars observed and fix their designations. A well-made globe of sufficient size is the best possible help, because it represents things wholly without dis- tortion, and is easily "rectified" (Astr. 528 *) for any given hour, so that the stars will all be found in the proper quarter of the (artificial) heavens, and in their true relations. But a globe is clumsy, inconvenient out of doors, and liable to dam- age ; and a good star-map properly used will be found but little inferior in efficiency, and much more manageable. 2. Star-Maps, Such maps are made on various systems, each presenting its own advantages. None are without more or less distortion, especially near the margin, though they 1 The references are to the articles in the Author's "Elements of Astron- omy," to ^hich this Uranography is a supplement. 473 8 URANOGRAPHY. [ 2 differ greatly in this respect. In all of them the heavens are represented as seen from the inside, and not as on the globe, which represents the sky as if seen from the outside; i.e., the top of the map is north, and the east is at the left hand ; so that if the observer faces the south and holds up the map before and above him, the constellations which are near the meridian will be pretty truly represented. 3. We give a series of four small maps which, though hardly on a large enough scale to answer as a satisfactory celestial atlas, are quite sufficient to enable the student to trace out the constellations and identify the principal stars. In the map of the north circumpolar regions (Map I.), the pole is in the centre, and at the circumference the right-ascension hours are numbered in the same direction as the figures upon a watch face; but with 24 hours instead of 12. The parallels of declination are represented by equidistant and concentric circles. On the three other rectangular maps, which show the equatorial belt of the heavens lying between + 50 and 50 of declination, the parallels of decima- tion are equidistant horizontal lines, while the hour-circles are vertical lines also equidistant, but spaced at a distance which is correct for declination 35, and not at the equator. This keeps the distortion within reasonable bounds even near the margin of the map, and makes it very easy to lay off the place of any object for which the right ascension and declination are given. The hours of right ascension are indicated on the central hori- zontal line, which is the equator, and at the top of the map are given the names of the months. The word September, for instance, means that the stars which are directly under it upon the map will be near the meridian about nine o'clock in the evening during that month. 4. The maps show all the stars down to the 4J magnitude all that are easily visible on a moonlight night. A few smaller stars are also inserted, where they mark some peculiar configuration or point out some interesting telescopic object. So far as practicable, i.e., north of 30 Decimation, the magnitudes of Pickering's " Harvard . Pho- tometry" are used. The places of the stars are for 1900. 474 4] THE CIRCUMPOLAR CONSTELLATIONS. 9 In the designation of clusters and nebulae the letter M. stands for Messier," who made the first catalogue of 103 such objects in 1784 ; e.g., 97 M. designates No. 97 on that list. A few objects from Herschel's catalogue are denoted by $ with a number following. The student or teacher who possesses a telescope is strongly urged to get Webb's "Celestial Objects for Common Telescopes." It is an invaluable accessory. (Longmans, Green & Co., N. Y.) THE CIRCUMPOLAR CONSTELLATIONS. We begin our study of Uranography with the constellations, which are drcumpolar (i.e., within 40 of the north pole), because these are always visible in the United States, and so can be depended on to furnish land (or rather sky) -marks to aid in identifying and tracing out the others. 5. Ursa Major, the Great Bear (Map I.). Of these cir- cumpolar constellations none is more easily recognizable than Ursa Major. Assuming the time of observation as about eight o'clock in the evening on Sept. 22d (i.e., 20 h sidereal time), it will be found below the pole and to the west. Hold the map so that the VIII. is at the bottom, and it will be rightly placed for the time assumed. The familiar Dipper is sloping downward in the northwest, composed of seven stars, all of about the second magnitude ex- cepting 8 (at the junction of the handle to the bowl), which is of the third. The stars a and /? are known as the " Pointers," because the line drawn from ft through a, and produced about 30, passes very near the Pole-star. The dimensions of the Dipper furnish a convenient scale of angular measure. From a to ft is 5 ; a to 8 is 10 ; ft to y, 8 ; from a to 7) at the extremity of the Dipper-handle (which, is also the Bear's tail) is 26. 6. The Dipper (known also in England as the "Plough," and as the " Wain," or wagon) comprises but a small part of 476 10 URANOGRAPHY. 18 * fche whole constellation. The head of the Bear, indicated by a scattered group of small stars, is nearly on the line from $ through a, carried on about 15 ; at the time assumed (20 h sid. time), it is almost exactly below the pole. Three of the four paws are marked each by a pair of third or fourth magnitude stars 1 J or 2 apart. The three pairs are nearly equidistant, about 20 apart, and almost on a straight line parallel to the diagonal of the Dipper-bowl from a to y, but some 20 south of it. Just now (20 h sid. time) they are all three very near the horizon for an observer in latitude 40, but during the spring and summer they can be easily made out. 7. Names 1 of Principal Stars. a. DUBHE. c. ALIOTH. ft. MERAK. . MIZAR. The little star near it is y. Phecda. Alcor, the "rider on his horse.* 1 8. Megrez. iq. BENETNASCH or Alkaid. Double Stars: (1) (Mizar), Mags. 3 and 5; Pos. 2 149; Dist. 14 ; '.5. In looking at this object the tyro will be apt to think that the small star shown by the telescope is identical with Alcor : a very low power eye-piece will correct the error. (Astr. Fig. 113.) The large star is itself a " spectroscopic binary " (see Art. 465*). (2) , the southern one of the pair which marks the left hind paw. Binary: Mags. 4 and 5; Pos. (1910) (about) 120, Dist. (about) 3". Position and distance both change rapidly, the period being only 61 years. This was the first binary whose orbit was computed. Clusters and Nebulae: (1) 81 and 82 M., A.R. 9 h 45 m , Dec. 69 44'. Two nebulse, one pretty bright, about half a degree apart. (2) 97 M., A.R. ll h 07 m , Dec. 55 43' 2 south-following /?. A planetary nebula. 1 Capitals denote names that are generally used ; the others are met with only rarely. 2 The " position angle " of a double star is the angle which the line drawn from the larger star to the smaller one makes with the hour-circle. It ie always reckoned from the north completely around through the east, as shown in Fig. A. 476 URSA MINOR, THE LESSER BEAR. 11 8. Ursa Minor, the Lesser Bear (Map I.). The line of the "Pointers" unmistakably marks out the Pole-star ("Polaris" or "Cynosura"), a star of the second magnitude standing alone. It is at the end of the tail of Ursa Minor, or at the extremity of the handle of the "Little Dipper/ 7 for in Ursa Minor, also, the seven principal stars form a dipper, though with the handle bent in a different way from that of the other Dipper. Beginning at "Po- laris " a curved line (concave towards Ursa Major) drawn through 8 and brings us to , where the handle joins the bowl. Two bright stars (second and third magnitude), ft and y, correspond to the pointers in the larger Dipper, and are known as the "Guardians of the Pole": ft is called "Kochab" The remaining corner of the bowl is marked by the faint star rj with another still smaller one near it. The Pole lies about 1 J from the Pole-star, on the line joining it to TJrsse Majoris (at the bend in the handle of the large Dipper). Telescopic Object. Polaris has a companion of the 9j magnitude, distant 18". 6, visible with a two-inch telescope. 9. Cassiopeia (Map I.). This constellation lies on the opposite side of the pole from the Dipper at about the same 477 FIG. A. Measurement of Distance and Position- Angle of a Double Star. 12 URANOGKAPHY. [5 9 distance as the " Pointers," and is easily recognized by the zigzag, " rail-fence " configuration of the five or six bright stars that mark it. With the help of the rather inconspicuous star *, one can make out of them a pretty good chair with the feet turned away from the pole, But this is wrong. In the recog- nized figures of the constellation the lady sits with feet towards the pole, and the bright star a is in her bosom, while and the other faint stars south of a, are in her head and uplifted arms: i, on the line from 8 to c produced, is in the foot. The order of the principal stars is easily remembered by the word Bagdei; i.e., ft } a, y, 8, c, i. Names of Stars : a (which is slightly variable) is known as SCHEDIR ; ft is called CAPH. Double Stars: (1) 77, Mags. 4-7 . Large star orange; small one purple. Pos. 170 , Dist. 5".5. Binary, with a period of some 200 years. Easily recognized by its position about half-way between a and y, a little off the line. (2) i/s A.R. l h 17 m , Dec. 67 21' ; Triple ; Mags. 4, 9 and 9 ; Pos. A to (B + C) 106, Dist. 29"; Pos. B-C 257, Dist. 2". 9. Found on a line from rj through y produced three times the distance rj-y : rather difficult for a four-inch telescope. 10. The Sidereal Time determined by the Apparent Position of Cassiopeia. The line from the Pole-star through Caph or ft Cassiopeiae (which is the leader of all the bright stars of the constella- tion in their daily motion) is almost exactly parallel to the Equinoc- tial Colure. When, therefore, this star is vertically above the Pole-star it is sidereal noon; it is 6* when it is on the great circle (not the par- allel of altitude) drawn from the Pole-star to the west point of the Horizon ; 12 h when vertically below it ; and 18 h when due east. A little practice will enable one to read the sidereal time from this celes- tial clock with an error not exceeding 15 or 20 minutes. 11. Cepheus (Map L). This constellation contains very few bright stars. At the assumed time (20 h sidereal) it is above and west of Cassiopeia, not having quite reached the meridian above the pole. A line carried from a Cassiopeise through ft and produced 20 (distance a . . . /3 = 5 nearly) 478 $11] DKACO. 13 will pass very near to a Cephei, a star of the third magnitude, in the king's right shoulder. ft Cephei is about 8 due north of a, and y about 12 from ft, both also of third magnitude : y is so placed that it is at the obtuse angle of a rather flat isosceles triangle of which ft Cephei and the Pole-star form the two other corners. Cepheus is represented as sitting behind Cassiopeia (his wife) with his feet upon the tail of the Little Bear, y being in his left knee. His head is marked by a little triangle of fourth magnitude stars, 8, c, and , of which 8 is a remarkable variable with a period of 5J days (see Astr. Table IV.). There are several other small variables in the same neighbor- hood, but none of them are shown on the map. Names of Stars: a is Alderamin, and ft is Alphirk. Double Stars: (1) ft, Mags. 3 and 8; Pos. 251; Dist. 14". (2) 8, Mags, larger star 3.7 to 5 (variable), smaller one 7; Pos. 192, Dist. 41" ; Colors, yellow and blue. (3) K, A.R. 20 h 13 m , Dec. 77 19' ; Mags. 4.5 and 8.5; Pos. 124; Dist. 7."5; Colors, yellow and blue. 12. Draco (Map I.). The constellation of Draco is char- acterized by a long, sinuous line of stars, mostly small, extend- ing half-way around the pole and separating the two Bears. A line from 8 Cassiopeise drawn through ft Cephei and ex- tended about as far again will fall upon the head of Draco, marked by an irregular quadrilateral of stars, two of which are of the 2 and 3d magnitude. These two bright stars about 4 apart are ft and y; the latter in its daily revolution passes almost exactly through the zenith of Greenwich, and it was by observations upon it that the aberration of light was discovered (Astr. 125). The nose of Draco is marked by a smaller star, //, some 5 beyond ft, nearly on the line drawn through it from y. From y we trace the neck of Draco, eastward and downward ! towards the Pole-star until we come to 8 and c and some smaller stars near them. There the direction of the line is reversed, 1 The description here applies strictly only at 20 h sid. time. 479 14 URANOGRAPHY. L 12 so that the body of the monster lies between its own head and the bowl of the Little Dipper, and winds around this bowl until the tip of the creature's tail is reached at the middle of the line between the Pointers and the Pole-star. The constella- tion covers more than 12 h of right ascension. 13. One star deserves special notice : a, a star of the 3J magnitude which lies half-way between Mizar ( Urs. Maj.) and the Guards (ft and y Urs. Min.) ; 4700 years ago it was the Pole-star, within 10' or 15' of the pole, and much nearer than Polaris is at present, or ever will be. It is probable that its brightness has considerably diminished within the last 200 years ; since among the ancient and mediaeval astron- omers it was always reckoned of the second magnitude. Names of Stars : a is THUBAN ; ft, Alwaid ; and y, Etanin. Double Stars: (1) p, Mags. 4 and 4|; Pos. 165; Dist. 2".5. Bi- nary, with a probable period of about 600 years. (2) e, Mags. 4, 8; Pos. 0.0; Dist. 2".9; yellow and blue. Nebula, A.R. 17 h 59 m ; Dec. 66 38 . Planetary, like a star out of focus. This object is almost exactly at the pole of the ecliptic, about midway between 8 and Draconis, but a little nearer . 14. Camelopardalis (Map I.) This is the only remaining one of the strictly circumpolar constellations a modern asterism contain- ing no stars above fourth magnitude, and constituted by Hevelius simply to cover the great empty s.pace between Cassiopeia and Perseus on one side, and Ursa Major and Draco on the other. The animal stands on the head and shoulders of Auriga, and his head is between the Pole-star and the tip of the tail of Draco. The two constellations of Perseus (which at 20 h sidereal time is some 20 below Cassiopeia) and of Auriga are partly circumpolar, but on the whole can be more conveniently treated in connection with the equatorial maps. Capella, the brightest star of Auriga, and next to Vega and Arcturus the brightest star in the northern hemisphere, at the time assumed (Sept. 22, 8 P.M.), is a few degrees above the horizon in the N.E. Between it and the nose of Ursa Major is part of the constellation of the Lynx, a modern asterism made, like Camelopar- dalis, merely to fill a gap. 480 j 15] MILKY WAY IN CIRCUMPOLAR REGION. 15 15. The Milky Way in the Circumpolar Region. The only circumpolar constellations traversed by it are Cassiopeia and Cepheus. It enters the circumpolar region from the constella- tion of Cygnus, which at 20 h sidereal time is just in the zenith, sweeps down across the head and shoulders of Cepheus, and on through Cassiopeia and Perseus to the northeastern horizon in Auriga. There is one very bright patch a degree or two north of ft Cassiopeiae ; and half-way between Cassiopeia and Perseus there is another bright cloud in which is the famous cluster of the "Sword Handle of Perseus" a beautiful object for even the smallest telescope. 16. Andromeda (Map II.). Passing now to the equato- rial maps and beginning with the northwestern corner of Map N"o. II., we come first to the constellation of Andromeda, which will be found exactly overhead in our latitudes about 10 o'clock in the middle of November, or at 8 o'clock a month later. Its characteristic configuration is the line of three second-magni- tude stars, a, /?, and y, extending east and north from a, which itself forms the K.E. corner of the so-called " Great Square of Pegasus," and is sometimes lettered as $ Pegasi. This star may readily be found by extending an imaginary line from Polaris through J3 Cassiopeise, and producing it about as far again : a is in the head of Andromeda, ft in her waist, and y in the left foot. About half-way from a to ft, a little south of the line, is 8 (of the third magnitude) with TT and e of the fourth magnitude near it. A line drawn northwesterly from ft nearly at right angles to the line fty, will pass through p at a distance of about 5, and produced another 5 will strike the "great nebula" (Astr. 470), which forms a little obtuse- angled triangle with v and a sixth-magnitude star known as 32 Andromedse. Andromeda has her mother, Cassiopeia, close by on the north, and at her feet is Perseus, her deliverer, while her Wead rests upon the 48! 16 URANOGRAPHY. [ 16 shoulder of Pegasus, the winged horse which brought Perseus to her rescue. To the south, beyond the intervening constellations of Aries and Pisces, Cetus, the sea-monster, who was to have devoured her, stretches his ungainly bulk. Names of Stars, a, A Ipheratz ; ft, Mirach; y, Almaach. Double Stars. (]) y, Mags. 3, 5; Pos. 62; Dist. 11"; colors, orange and greenish blue a beautiful object. The small star is itself double, but at present so close as to be beyond the reach of any but very large instruments (Astr. Fig. 113). (2) TT (2 N. and a little west of 8), Mags. 4, 9; Pos. 174; Dist. 36"; white and blue. Nebulce. M. 31; the great nebula; visible to naked eye. M. 32; small, round, and bright, is in the same low-power field with 31 ; south and east of it. 17. Pisces (Map II.). Immediately south of Andromeda lies Pisces, the first of the zodiacal constellations, though now occupying (in consequence of precession) the sign of Aries. It has not a Dingle conspicuous star, and is notable only as con- taining the vernal equinox, or first of Aries, which lies near the southern boundary of the constellation in a peculiarly star- less region. A line from a Andromedse through y Pegasi con- tinued as far again strikes about 2 east of the equinox. The body of the southern fish lies about 15 south of the middle oi the southern side of the great square of Pegasus, and is marked by an irregular polygon of small stars, 5 or 6 in diameter. A long crooked " ribbon " of little stars runs eastward for more than 30, terminating in a Piscium, called El Rischa, a star of the fourth magnitude 20 south of the head of Aries. From there another line of stars leads up N.W. in the direction of 8 Andromedse to the northern fish, which lies in the vacant space south of (3 Andromedse. Double Stars. (1) a, Mags. 4, 5.5; Pos. 324; Dist. 3". (2) \f/ f (2 S.E. of rj Andromedse see map), Mags. 4.9, 5; Pos. 160; Dist. 31". 18. Triangnluin (Map II.). This little constellation, insignifi- cant as it is, is one of Ptolemy's ancient 48. It lies half-wav be- tween y Andromedae and the head of Aries, characterized by three stars of the third and fourth magnitudes. 482 18] ABIES. 17 Double Stars. (1) t or 6 (5 nearly due south of ft Trianguli, and at the obtuse angle of an isosceles triangle of which a and y are the other two corners), Mags. 5, 6.5; Pos. 76; Dist. 4"; topaz-yellow and green. 19. Aries (Map II.). This is the second of the zodiacal constellations (now occupying the sign of Taurus). It is bounded north, by Triangulum and Perseus, west by Pisces, south by Cetus, and east by Taurus. The characteristic star-group is that composed of a, ft. y (see map), about 20 due south of y Andromedse : a, a star of the 2i magnitude is fairly conspicu- ous, forming as it does a large isosceles triangle with ft and y Andromedse. Names of Stars, a, Hamal ; ft, Sheratan ; y, Mesartim. Double Stars. (1) y, Mags. 4.5, 5; Pos. 0; Dist. 8".8. (This is probably the earliest known double star ; noticed by Hooke in 1664.) (2) e, Mags. 5, 6.5; Pos. 200; Dist. 1 ".2. (About one-third of the way from a Arietis towards Aldebaran, is 4 beyond it on the same line.) This is probably too difficult for any instrument less than 4 or 4| inches' aperture. (3) TT, Triple ; Mags. 5, 8.5, and 11 ; A-B, Pos. 122; Dist. 3".l; A-C, Pos. 110; Dist. 25". (At the southern corner of a nearly isosceles triangle formed with e and T, c being at the obtuse angle.) The star 41 Arietis (3| mag.), which forms a nearly equilateral tri- angle with a Arietis and y Trianguli, constitutes, with two or three other small stars near it, the constellation of Musca (Borealis), a con- stellation, however, not now generally recognized. 20. Cetns (Map II.). South of Aries and Pisces lies the huge constellation of Cetus, which backs up into the sky from the southeastern horizon. The head lies some 20 S.E. of a Arietis, marked by an irregular pentagon of stars, each side of which is 5 or 6 long. The southern edge of it is formed by the stars a (2 mag.) and y (3|- mag.) : 8 lies nearly south of y. ft, the brightest star of the constellation (2d magnitude), stands alone nearly 40 west and south of a. About half-way 483 18 UKANOGRAPHY. [ 20 from ft to y the line joining them passes through a character- istic quadrilateral (see map), the N.E. corner of which is com- posed of two fourth-magnitude stars, and x- The remarkable variable o Ceti (Mira) lies almost exactly on the line joining y and , a little nearer to y than to . It is visible to the naked eye for about a month or six weeks every eleven months, when near its maximum. Names of Stars, a, MENKAR; ft, Diphda or Deneb Kaitos ; , Eaten Kaitos ; o, MIRA. Double Stars. (1) y, Mags. 3.5, 7; Pos. 290; Dist. 2".5; yellow and blue. South of Cetus lies the constellation of Sculptoris Apparatus (usu- ally known simply as Sculptor), which, however, contains nothing that requires notice here. South of Sculptor, and close to the horizon, even when on the meridian, is Phoenix. It has some bright stars, but none easily observable in the United States. 21. Perseus (Maps I. and II.). Returning now to the northern limit of the map, we come to the constellation of Perseus. Its principal star is a, rather brighter than the standard second magnitude, situated very nearly on the pro- longation of the line of the three chief stars of Andromeda. A very characteristic configuration is " the segment of Per- seus" (Map I.), a curved, line, formed by 8, a, y, and 17, with some smaller stars, concave towards the northeast, and run- ning along the line of the Milky Way towards Cassiopeia, The remarkable variable star /?, or Algol (Astr. 453), is situ- ated about 9 south and a little west of a, at the right angle of a right-angled triangle which it forms with a (Persei) and y Andromedse. Some 8 south and slightly east of 8 is e, and 8 south cf e are and o of the fourth magnitude in the foot of the hero. Algol and a few small stars near it form " Medusa's Head." Names of Stars, a is Marfak, or ALGENIB ; (3 is ALGOL. Double Stars. (1) e, Mags. 3.5, 9; Pos. 10; Dist. 8".4. (2) fc 484 21] AURIGA. 19 Quadruple; Mags. 3.5, 10, 11, 12; Pos. A-B, 207; Dist. 13".2, 83", 121". (3) 77, Mags. 5, 8.5; Pos. 300; Dist. 28"; orange and blue. Clusters. (1) # VI. 33 and 34. Magnificent. Half-way between y Persei and 8 Cassiopeise. (2) M. 34; A.R. 2 h 34 m ; Dec. 42 11'; coarse, with a pretty double star (eighth mag.) included. 22. Auriga (Maps I. and II.). Proceeding east from Per- seus we come to Auriga, instantly recognized by the bright yellow star CAPELLA (the Goat) and her attendant Hoedi (or Kids). Capella, a Aurigse, according to Pickering, is precisely of the same brightness as Vega (Mag. = 0.2), both of them being about \ of a magnitude fainter than Arcturus, but dis- tinctly brighter than any other stars visible in our latitudes except Sirius itself. About 10 east of Capella is ft Aurigse of the second magnitude, and 8 south of ft is of the third magnitude; 8 Aurigse is 10 north of ft in the circumpolar region, c, , and 17, 4 or 5 S.W. of a, are the "Kids." Names of Stars, a, CAPELLA ; ft, MENKALINAN. Double Stars. (1) w, Mags. 5, 9; Pos. 353; Dist. 7"; white, light blue, ft is a spectroscopic double (see Art. 465*). Clusters. (1) M. 37; A.R. 5 b 44 m ; Dec. 32 31' (on the line from Aurigse to Tauri, one-third of the way from 0). Fine for small instrument. (2) M. 38; A.R. 5 h 21 m ; Dec. 35 47'. Nearly at the middle of the line from to