746 THE POPULAR SCIENCE MONTHLY. 



pawn-shops. Ask to be shown the old and well-tried articles ; you 

 may find among them a second-hand glass of fine optical properties. 

 If the lenses are not injured one need not trouble himself about the 

 worn appearance of the outside of the instrument ; so much the more 

 evidence that somebody has found it well worth using. 



A good field or marine glass is in some respects better than an 

 opera-glass for celestial observations. It possesses a much higher 

 magnifying power, and this gives sometimes a decided advantage. 

 But, on the other hand, its field of view is smaller, rendering it more 

 difficult to find and hold objects. Besides, it does not present nearly 

 as brilliant views of scattered star - clusters as an opera-glass does. 

 For the benefit of those who possess field-glasses, however, I have 

 included in this brief survey certain objects that lie just beyond the 

 reach of opera-glasses, but can be seen with the larger instruments. 



Having selected your glass, the next thing is to find the stars. Of 

 course, one could sweep over the heavens at random on a starry night 

 and see many interesting things, but he would soon tire of such aim- 

 less occupation. One must know what he is looking at in order to 

 derive any real pleasure or satisfaction from the sight. 



The circular map here given represents the appearance of the heav- 

 ens, at 9 o'clock p. m., on or about the 1st of April. The center of the 

 map is the zenith, or point overhead. The reader must now exercise 

 his imagination a little, for it is impossible to represent the true ap- 

 pearance of the concave of the heavens on flat paper. Holding the 

 map over your head, with the points marked East, "West, North, and 

 South in their proper places, conceive of it as shaped like the inside, 

 of an open umbrella, the edge all around extending clear down to the 

 horizon. Suppose you are facing the south, then you will see, up near 

 the zenith, the constellation of Leo, which can be readily recognized 

 on the map by six stars that mark out the figure of a sickle standing 

 upright on its handle. The large star in the bottom of the handle is 

 Regulus. Having fixed the appearance and situation of this constella- 

 tion in your mind, go out-of-doors, face the south, and try to find the 

 constellation in the sky. With a little application you will be sure to 

 succeed. 



Using Leo as a basis of operations, your conquest of the sky will 

 now proceed more rapidly. By reference to the map you will be able 

 to recognize the twin stars of Gemini, southwest of the zenith and 

 high up ; the brilliant lone star, Procyon, south of Gemini ; the daz- 

 zling Sirius, flashing low down in the southwest ; Orion, with all his 

 brilliants, blazing in the west ; red Aldebaran and the Pleiades off to 

 his right ; and Capella, bright as a diamond, high up above Orion, 

 toward the north. In the southeast you will recognize the quadrilateral 

 of Corvus, with the singularly white star Spica glittering near the 

 horizon east of it. 



Next face the north. If you arc not just sure where north is. 



