30 KANSAS CITY REVIEW OF SCIENCE. 



His theory differs from that of Faye chiefly in localizing the phenomena of 

 precipitation instead of regarding it as proper to all portions of the photosphere, 

 and in supposing the precipitation confined to one or two elements. He attributes 

 the granular appearance of the solar surface to ascending currents directed gener- 

 ally from the center of the sun. About these currents are necessarily currents in an 

 opposite direction, which serve to maintain a general equilibrium in the distribu- 

 tion of mass. The ascending currents start from a level where the temperature is 

 probably above the vaporizing temperature of every substance. As they move 

 upward the vapors are cooled, mainly by expansion, until a certain element 

 (probably of the carbon group) is precipitated. This precipitation, restricted 

 from the nature of the action, forms the granules. The precipitated material rap- 

 idly cools, on account of its great radiating power, and forms a fog or smoke, 

 which settles through the spaces between the granules till revolatiHzed below. It 

 is this smoke which produces the general absorption at the sun's limb and the 

 "rice grain" structure of the photosphere. The reasons for supposing the pre- 

 cipitated element to be of the carbon group — carbon or silicon — is simply that no 

 other substances present the properties indicated by the cloud masses of the pho- 

 tosphere. It is pretty clear that the substance has a boiling point above that of 

 iron, for iron vapor at a lower temperature exists in its immediate neighborhood. 

 The element is not a rare one, and its molecular weight cannot be great, for though 

 precipitated below the upper natural limit of its vapor, there are few elements 

 found in abundance above it, and those in general of low vapor density. It is 

 possible that the light coming from the sun is radiated from solid or liquid parti- 

 cles of carbon just at the point of vaporization ; but Mr. Hastings is rather in- 

 clined to suspect that the photospheric material is silicon. There is also good 

 reason to suppose, he thinks, that carbon is precipitated at a higher level, possi- 

 bly along with the less common element boron. 



The clouds of carbon or other smoke would naturally be drifted into spaces of 

 downward flowing currents, thus forming sun spots, the characteristics of which 

 are accounted for by the necessary behavior of smoke clouds sinking into re- 

 gions of higher temperature. This explanation of sun spots and their allied phe- 

 nomena is certainly plausible, and we shall look with interest for what older stu- 

 dents of the sun shall have to say about it. — Scientific News. 



A writer in the Jetvish World points out that, contrary to the received idea, 

 the elder Rabbins of the Talmud taught that the world was round. This is shown 

 by a passage, in which, in discussing idolatry, the figures holding in the hand a 

 baton, a bird, or a globe, were prohibited, because the baton symbolizes the do- 

 minion of the world, the bird that the world lies beneath it, and the globe is for- 

 bidden because it resembles the form of the world itself. 



