the Distribution of Heat over the Globe. 95 



heat received at the equator to that received at the poles, sup- 

 posing the proportionate quantity absorbed by the atmosphere 

 to be the same in both cases, is as 12 to 4*98, or, say, as 12 to 

 5. Consequently, if the temperatures of the equator and the 

 poles be taken as proportionate to the absolute amount of heat 

 received from the sun, then the temperature of the equator 

 above that of space must be to that of the poles above that of 

 space as 12 to 5. What ought, therefore, to be the tempera- 

 tures of the equator and the poles, did each place depend solely 

 upon the heat which it receives directly from the sun ? Were 

 all ocean- and aerial currents stopped, so that there could be no 

 transference of heat from one part of the earth's surface to the 

 other, what ought to be the temperatures of the equator and 

 the poles ? We can at least arrive at a rough estimate on this 

 point. If we diminish the quantity of warm water conveyed 

 from the equatorial regions to the temperate and arctic regions, 

 the temperature of the equator will begin to rise and the tem- 

 perature of the poles to sink. It is probable, however, that this 

 process would affect the temperature of the poles more than it 

 would do that of the equator ; for as the warm water flows from 

 the equator to the poles, the area over which it is spread be- 

 comes less and less. But as the water from the tropics has to 

 raise the temperature of the temperate regions as well as the 

 polar, the difference of effect at the equator and poles might 

 not, on that account, be so very great. Let us take a rough 

 estimate. Say that, as the temperature of the equator rises one 

 degree, the temperature of the poles sinks one degree and a half. 

 The mean annual temperature of the globe is about 58°. The 

 mean temperature of the equator is 80°, and that of the poles 0°. 

 Let ocean- and aerial currents now begin to cease, the tempera- 

 ture of the equator begins to rise and the temperature of the 

 poles to sink. For every degree that the equator rises the poles 

 sink 1-J°; and when the currents are all stopped and each place 

 dependent alone upon the direct rays of the sun, the mean an- 

 nual temperature of the equator above that of space will be to 

 that of the poles, above that of space, as 12 to 5. When this 

 proportion is reached, the equator will be 374° above that of 

 space, and the poles 156° ; for 374 is to 156 as 12 is to 5. The 

 temperature of space we have seen to be —239°, consequently 

 the temperature of the equator will in this case be 135°, rec- 

 koned from the zero of the Fahrenheit thermometer, and the 

 poles 83° below zero. The equator would therefore be 55° 

 warmer than at present, and the poles 83° colder. The differ- 

 ence between the temperature of the equator and the poles will 

 in this case amount to 218°. 



Now*, if we take into account the quantity of positive energy 



