THE EARTH IN METEORIC SHADOW. 169 



matter between the sun and the earth at a particular 

 date ; and it must not be too readily assumed that the 

 effect of it would be insignificant. Dull brown or 

 black bodies, such as meteors, receive far more light 

 than they reflect, and yet at solar eclipses, photographs 

 of the light they do reflect can be taken in a very 

 short time.' So that it is reasonable to admit at least 

 the possibility that the intervention of meteors under 

 ordinary circumstances may perceptibly affect the sun's 

 heat and give rise to the sudden falls of temperature 

 we have described. 



Mr. Russell appears to suppose that in the corona 

 there may be streamers projecting from the sun's 

 surface directly towards the earth, and others on the 

 side remote from us projecting directly from the earth. 

 This, however, is not possible, so far as the meteoric 

 corona is concerned. A dense meteor stream passing 

 close by the sun's surface may, from particular points 

 of view, appear to extend radially from the sun, but 

 there is no position which the earth can possibly 

 assume in which such a meteor stream would be 

 directed radially from the sun towards us. The 

 earth can be so situated that the rich part of a 

 meteor stream may be pointed (so to speak) directly 

 towards her ; but whenever that is the case the meteor 

 stream is removed to some distance from the line 

 towards the sun. In point of fact, to suppose that a 

 portion of a meteor stream can be radial from the sun 

 in any direction whatever is equivalent to supposing 

 that a part of an elliptical orbit around the sun can be 



