AND THE OTHER PLANETS OP THE SOLAR SYSTEM. 653 



calculated. Adopting Dove's results*, and calculating Q by the formulae given by Poissonj-, 

 we have 



« - 26°,5 (C) 

 Q = ,95910 



u = 21° 



Q = ,77397 



«„ - 6°,35 

 Q = ,66662 



> at the Equator. 



} 



} 



in latitude 30° N. 

 48°.50' N. 



M = — 7° 5 ) 



> at the Arctic Circle. 

 Q = ,47729] 



i° = - l6°,5l 

 3 = ,398/ 



M = — 



"TJ at the Pole. 



Hence we obtain 



\jV + s = w - AQ 



= 26°, 5 - 34°,5 



= - 8° (C) at the Equator. 

 yj, + s, = 21° - 27°, 72 



= - 6°,72 in lat. 30°. 

 ^ + s 2 = 6°,35 - 23°,76 



= - 17°,41 in lat. 48°. 50'. 

 xj, + Si = - 7°,5 - 17°,3 



= - 24,°8 at the Arctic Circle. 



x// + S 4 = 



= - 16°,5 - 14°,4 



= - 30°,9 at the Pole. 



From these equations we can obtain the differences between any two of the quantities 

 s , s, , &c. Thus (omitting for the present s z which would give an anomalous result) we have 



s -s 2 = 9°,41, 



s - s 3 = l6 °> 8 > 

 s - s 4 = 22°,9. 



These numbers express the differences between the effects of the Sun in different latitudes on 

 the Earth's superficial temperature (u ), arising from the increased temperature of the atmo- 

 sphere, in addition to the direct effect of the heat which radiates through the atmosphere and 

 is absorbed by the Earth's surface. Thus this effect on u at the equator exceeds the similar 

 effect in the latitude of Paris by 9°,41 (C), at the Arctic Circle by ]6°,8, and at the Pole by 

 22°,9. Let us compare these differences with the differences in the quantities of heat which 



* Distribution of Heat over the Surface of the Globe, p. 14. + Theorie de la Chaleur, p. 487. 



