82 



THE GUIDE TO NATURE 



in the west that it is in very unfavor- 

 able position for observation. By Sep- 

 tember I it will have passed beyond the 

 borders of our evening map, but on this 

 date the great Jupiter will be just en- 

 tering the map in the east, and this 

 beautiful world, with its retinue of 

 bright moons, will shine in our evening 

 skies throughout the entire winter. On 

 August ID, the faint Uranus, which is 



the heavens, the delicate fainter groups, 

 such as the Maiden's Hair, the Crown, 

 the Arrow, the striking little figure 

 known as the Dolphin or Job's Col^n, 

 and many others can be gradually ad- 

 ded, imtil the whole summer heavens 

 has become familiar to him. 



It is in Andromeda, at N, Figure i, 

 that there is found the wonderful Great 

 Xebula, while at the point C of the 



5A5t 



HOfei:z.otsl 



Figure 2. The eastern heavens at 3 A. M., August 25, showing X'enus, Jupiter 

 and .Saturn, the last about to be occulted bv tlie crescent moon. 



just visible to the naked eye, will come 

 into opposition with the sim, and so be 

 nearest the earth This will be the most 

 favorable time of the year for observ- 

 ing this very large but very distant 

 world. 



The August Stars. 

 The slow progression of the seasons 

 has brought the Great Square of Pe- 

 gasus and the bright xA-udromeda into 

 our evening sky, while the summer 

 branch of the Milky Way with its 

 train of bright groups, extending from 

 Sagittarius in the south to Perseus in 

 the north, has now become raised al- 

 most to the zenith. With this beauti- 

 ful pathway to guide him. the merest 

 ])eginner in astronomy can readily 

 trace out many of the larger summer 

 groups, of which the most easily found 

 are Scorpio, the Archer, the Eagle, the 

 Northern Cross, and Cassiopeia. Hav- 

 ing thus made a beginning and, as it 

 were, fotmd his bearings on the face of 



constellation Hercules there is the 

 wonderful cluster of 60,000 stars. Both 

 of these objects are just visible to the 

 naked eye on a clear night, and they 

 can hence be well stitdied with even a 

 small telescope, though it reqttires a 

 large glass to reveal much of their won- 

 derftil beauty. The intricate detail of 

 the former, showing how it consists 

 of a great winding spiral apparently 

 condensing into a solar system, can in 

 fact only be detected through a long 

 exposure of the photographic plate. 



Almost exactly in the zenith there 

 shines out the brilliant, blue Vega, p 

 wonderful sim immenselv larger and 

 immensely hotter than our own sun, 

 which is so far away that the light 

 with which we view it has been 21 

 years and 8 months on its journey to 

 tis Vega is receding from us with a 

 speed of nine miles a second ; it is also 

 drifting slowly in a transverse direc- 

 tion and so changing its position 



