TO KNOW THE STARRY HEAA'ENS 



233 



by the naked-eye cluster of stars at A 

 (Figure i), the shoulders being at B and 

 C; the (bent) right knee is at E and the 

 left foot at D. The stream of stars from 

 H to K represents the Lion's Skin, held 

 on the left hand and arm, while the right 

 hand is at L. The orange-reddish star 

 at B is the brightest star of the constella- 



but how much solid matter there may also 

 be involved in it we do not know. The 

 spectra of certain of its stars are so iden- 

 tical with its own that it is practically 

 certain that these are immersed in and 

 are a part of the cloud itself. 



As to the true size of this great cloud, 

 it is so great as to be entirely inconceiv- 



HOTZTH. 



SOUTH. 



Figure 1. The Heavens at 9 P. M.. December 1. (If facing south, hold the map 

 upright. If facing east hold East below". If facing west, hold West below. If facing 

 north, hold map inverted.) 



tion, while the bluish sun at D is next 

 in brilliance. The former is irregularly 

 variable, so much so that in December, 

 1852, it was actually for a short time the 

 brightest star of the entire heavens ; the 

 latter is a triple star. 



New Discoveries in the Nebula of 

 Orion. 



It is, however, in the position X that 

 there is found what is by far the most 

 wonderful object in this constellation. 

 This is the very well-known nebula in 

 Orion, the greatest nebula of the sky and 

 a beautiful object of wonderful complex- 

 ity. This is one of the purely gaseous 

 nebulas ; that is, the light with which we 

 view it emanates from luminous gases, 



able. If we can imagine a great globe 

 formed about our sun, and so large that 

 it will always contain our moving earth 

 within it — that is, if we imagine the dis- 

 tance through this globe to be about two 

 hundred millions of miles, then it is cer- 

 tain that it would require more than one 

 million of these globes to equal in bulk 

 this great nebulous cloud. 



Very recently the announcement of cer- 

 tain results from wonderfully delicate 

 measurements has attracted the attention 

 of astronomers anew to this extraordi- 

 nary object. By two quite different pro- 

 cesses it has been found possible to meas- 

 ure in miles per second the velocity with 

 which any selected portion of the nebula 

 is moving toward us or awav from us, 



