Jan. 13, 1882.] 



- KNOV/LEDGE • 



221 



culty. His largest moon, Titan, will be seen at once, and 

 Japetus (wliich was visible, as shown, when the drawing 

 was made) may, perhaps, be picked up. Tethys, Dione, 

 and Rhoea, are too severe tosts for a 3-in. object-glass, and 

 the other three satellites are hopelessly beyond much larger 

 instruments. The incipient astronomer must not expect to 

 perceive all the wonderful Saturnian detail shown in astro- 

 nomical books. Should his 3-iii. telescope show him ex- 

 actly what is exhibited in the engraving, he may rest 

 assured that he is the possessor of a first-rate instrument. 

 Neptune, who may be found from the map, will be undis- 

 tinguishable from a fixed star with the optical means at our 

 command. Jupiter, however, represented in our next figure, 



Jupiter. 



is a brilliant and most conspicuous object, and the eye of 

 the novice will have to become accustomed to the brilliance 

 of his light before much detail can be made out upon his 

 surface. At the period in his rotation, corresponding to 

 that at whicli our sketch was taken, the great red spot 

 which has been such a conspicuous object on his disc for 

 the last two or three 3-ears wOl be at once recognised ; a 

 dark belt to the east, and somewhat above (or south of) it, 

 bending down seemingly towards it. Then, north of 

 the great spot, we note a well-defined band, the darkest 

 portion of the planet's surface. The northern edge of this, 

 and the southern edge of a belt nearly on the planet's 

 equator, enclose an irregularly-formed lighter area between 

 them. They are succeeded by a third dark belt, after 

 which the whole of the planet's limb up to his north pole 

 is covered ^vith a continuous shading. Jupiter has four 

 moons, but their positions are so continually shifting as to 

 render it impossible to insert them in any drawing, unless 

 its exact epoch be given. They may all four be outside of 

 the planet's disc, or on the same side, or some on one side 

 and some on another. Or they, or one or more of them, 

 may be hidden in the shadow of Jupiter, or be passing 

 across his face. In this latter case, the shadow of the 

 crossing satellite may be detected like a little circular dot 

 of ink upon his face. Our sketch of Jupiter, we must warn 

 the young observer, is made on a smaller scale than that 

 of Saturn, the latter having been enlarged to exhibit 

 detail. When the observer has gazed his fill upon tliis 

 superb planet, he may raise his telescope to that lovely 

 object y AndromediB (above Triangula in the map). The 

 contrast between the yellow of the large star and the ex- 

 quisite green of the small companion is very striking, tt 

 AndromediB to the right of /3 is a very pretty object, the 

 contrasting colours being in this case very pale yellow and 

 blue. 59, 2 3, P. XXIII., 240, and other beautiful pairs 

 will be found marked in Proctor's "Atlas." 



Exchanging now his high power for the lowest one 



supplied with his telescope, the beginner should fish a 

 little abov(> to the right of y Andromedffi (see map, p. 204) 

 for that most remarkable object, 31 of "Messier's Cata- 

 logue," the well-known great nebula in Andromeda. Sir 

 John Ilerschcl quotes Simon Marius as describing the 

 appearance of this nebula as resembling that of a candle 

 shining through horn ; and this really does not give a bad 

 idea of it, as viewed in such an insti-ument as that which 

 we are using. We purposely abstain from giving any 

 figure of this nebula, inasmuch as no woodcut is competent 

 to reproduce the peculiar effect of a nebula, and our object 

 is to show as exactly as possible what the reader, furnished 

 with a first-class 3-inch achromatic, may expect it to show 

 him. 



None of the larger stars in Taurus present any features 

 of interest in small telescopes, j^ Tauri is a somewhat wide, 

 but pretty pair. It is the one above the letter S in the word 

 "Taurus" in the map on page 119. Identification of the 

 smaller ones without graduated circles is almost hopeless. 

 Using a low eye-piece through, the Pleiades present a fine 

 spectacle ; and about two diameters of the moon, above 

 and to the right of i Tauri, will be found a pale, elongated 

 nebula. A low eye-piece, too, must be used for this. Nearly 

 over head, just now, Perseus will be observed ; a constella- 

 tion rich in objects of interest, of which, however, we can 

 only give an account of a very few suitable for the instru- 

 ment we are employing. Reference, as before, must be 

 made to the maps on pages 97, 119, and 204 for their identi- 

 fication. £ is a very tine pair, but the small er star requires 

 some little looking for. It is as shown in Fig. 8 below, 

 and just to the right of its primary. I Persei is really 

 a quadruple star, although the student will scarcely discern 

 more than three out of its four components with the aper- 

 ture we are considering, i) is another pretty pair, too, 

 but somewhat difficult, from the faintness of the com- 

 panion. Perseus contains several interesting clusters — 

 notably one of the most glorious fields of stars in the 

 whole heavens, in what is called the " Sword-handle." 

 This may be seen by a sharp-sighted person with the 



Fig. 8. — t Persei 



naked eye between Perseus and Cassiopeia (map on p. 75) 

 as a bright spot in the MOky Way. This superb object 

 requires the lowest eye-piece in the observer's possession to 

 do it anything like justice. No view of it, however, with so 

 small an aperture will give any idea of the gorgeous effect 

 it presents in a large instrument 



South of Aries and the Pleiades lies the straggling con- 

 stellation Eridamus. It contains numerous interesting 

 pairs of stars ; but for them the student must sweep, if 

 confined to the maps in Knowledge, as they are not 

 numbered there ; and hence, any attempted description of 

 their localities could only be confusing. 32, 39, 55, and 

 P III., 98 will all be found to be beautiful and attractive 

 objects, and are marked in Proctor. A curious planetary 

 nebula ^ IV. 26, seen best witli a low power, will be found 

 there too. Having then furnished the incipient star-gazer 

 with a good hard night's work, we take leave of him for the 

 present. In our next lesson we propose to deal with that 

 splendid and all-repaying constellation, Orion. 



