78 LIGHT SCIENCE FOR LEISURE HOURS. 



THE GREAT NEBULA IN ORION. 



DURING the first four months of the year, the constella- 

 tion Orion is very favourably situated for observation 

 in the evening. This magnificent asterism is more 

 easily recognised than the Great Bear, Cassiopeia's 

 Chair, or the fine festoon of stars which adorns the 

 constellation Perseus. There is, indeed, a peculiarity 

 about Orion which tends considerably to facilitate 

 recognition. The other constellations named above, 

 gyrate round the pole in a manner which presents 

 them to us in continually varying positions. It is not 

 so with Orion. Divided centrally by the equator, the 

 mighty hunter continues twelve hours above and twelve 

 hours below the horizon. His shoulders are visible 

 somewhat more, his feet somewhat less, than twelve 

 hours. When he is in the south, he is seen as a giant 

 with upraised arms, erect, and having one knee bent, 

 as if he were ascending a height. Before him, as if 

 raised on his left arm, is a curve of small stars, forming 

 the shield, or target of lion's skin, which he is repre- 

 sented as uprearing in the face of Taurus. When Orion 

 is in the east, his figure is inclined backwards ; when 

 he is setting, he seems to be bent forwards, as if rush- 

 ing down a height ; but he is never seen in an inverted 

 position, like the northern constellations. 



And we may note in passing, that the figure of Orion, 



