Chase.] 



268 



[September. 



of Challis, Rankine, and Helmholtz may be so interpreted as to cor- 

 roborate such a hypothesis. I am not aware, however, that any one 

 has hitherto attempted to verify the theory by observation, or to 

 point out any path by which cosmical tests may be attainable. 



I do not feel that the tests which 1 have here submitted are well- 

 defined enough to warrant any present attempt at a complete me- 

 chanical interpretation of the ratios to which they lead. But in any 

 future mathematical or empirical investigations on the subject, it may 

 be well to keep in view the following propositions : 



1. The motions of every particle of the earth's atmosphere are 

 controlled, mainly, by the tendency to equilibrium between the solar 

 and terrestrial attractions. 



2. The undulations (of light, heat, etc.) which radiate from the 

 surface of the solar photosphere, originate at a point where the sun's 

 attractive energy is [354936 -f- (44|o a o)3^] 28.56 times as great 

 as the earth's superficial attraction. 



3. If two equal material particles are kept asunder by an inter- 



Table IV. — Average North American Intersolstitial 



Range. 



Av. Bar. Kange 



180° 



1°.398 



Av. Bar. Height .867 



(Av. Ther. Range) 47°.li5 ^ 1°.898 =83.823 



