ge, 
J. R. Mayer on Celestial Dynamics. 195 
compared with that of water, we find the heat developed by the 
asteroid to be from 7000 to 14,000 times greater than that of 
the oxyhydrogen mixture. From data like these, the extraordi- 
nary diathermic energy of the sun’s rays, the immense radiation 
from his surface, and the high temperature in the focus of the 
Teflector are easily accounted for. 
The facts above mentioned show that, unless we assume on 
the sun the existence of matter with unheard of chemical pro- 
rties as a deus ex machind, no chemical process could maintain 
the present high radiation of the sun; it also follows from the 
ficial light appears dark in comparison with the sun’s light, so 
the mechanical processes of the heavens throw into the shade 
The quality of the sun’s rays, as dependent on his tempera- 
ture, is of the greatest importance to mankind. If the solar heat 
were originated by a chemical process, and amounted near its 
Teach the surface of our earth and warm it. ‘T’he comparatively 
low temperature of the terrestrial surface 18 the cause why the 
heat cannot easily radiate back through the atmosphere into the 
Universe. The atmosphere acts, therefore, like an envelope, 
Which is easily pierced by the solar rays, but which offers con- 
siderable resistance to the radiant heat i from our earth ; 
— — resembles that of a valve — a we an to pass 
y in one direction, but stops the flow in the 0 ; 
: , : eatest importance as 
The action of the atmosphere 1s of the gr It mee the 
l i 
Mean temperature of the earth’s surface. After the setting of 
