54 M. POUILLET ON SOLAR HEAT, 
8. Having ascertained the quantity of heat which the sun 
sends to the earth during 1', by its perpendicular action upon 
a square centimetre, it is easy to determine the total quantity of 
heat which the entire globe of the earth and the atmosphere 
receive each minute. In fact, that quantity of heat is what 
would fall upon the circle of illumination if the hemisphere of 
the earth, which is at the same time illuminated and heated by 
the sun, were removed. Now the surface of this circle of illumi- 
nation being +R%, the total quantity of heat which it receives is 
1°7633 . rR. 
If this heat were uniformly dispersed over all points of the 
earth, each square centimetre would receive for its share only 
1°7633 . 2 R? 
4x R? 
It is easy to see, according to this, that in the course of a year 
the total quantity of heat received by the earth from the sun is 
the same as if, during that interval, there should enter, by each 
square centimetre of the surface which limits the atmosphere, 
231675 unities. 
or 0°4408. 
By transforming this quantity of heat into a quantity of melted 
ice, we obtain the following result :— 
If the total quantity of heat which the earth receives from the 
sun in the course of a year were uniformly dispersed over all 
points of the globe, and if it were there employed, without any 
loss, in dissolving ice, it would be capable of dissolving a stratum 
of ice which would envelope the whole earth, and which would 
have a thickness of 30™89, 
or nearly 31 metres ; such is the simplest expression of the total 
quantity of heat which the earth receives every year from the 
sun. 
9. The same fundamental datum enables us to solve another 
question, which will perhaps appear more bold, and the solution 
of which is nevertheless quite as simple. It enables us to find 
the total quantity of heat which escapes from the entire globe 
of the sun in a given time, without supposing anything, except 
that all the equal portions of the globe of the sun emit equal 
quantities of heat; this appears hitherto confirmed by experi- 
ment, since the different aspects which the sun presents to us 
