Dr Brewster on the Mean Temperature of' the Equator. 119 



T 



observations, either by the* formula Eq. temp. =:• = — ac- 



COS. .Li. 



cording to the principle of my formula, or by the formula 



T 

 Eq. temp.= ^-y- according to the principle of Mayer's for- 

 mula, we shall obtain the following results :— 



Mean Temp, of Equator. 

 „ „. T „ m T 



Means, 80 .66 81 .32 



Mean of both, 80°.99 

 It follows, therefore, from the Ceylon observations, that the 

 mean temperature of the Equator is less than 81 \°. 



The Batavian observations give the following results :— 



Mean Temp. 

 Batavia, as given by Humboldt, - 80°.42 



Do. in 1758, Dr Kriel,* - 78 .5 



Do. near the sea-shore, according to Professor Rein ward t, 82 

 Do at Buitenzoig, 737 feet high,t - 8U 



Hence, we obtain for the equatorial temperature, 



Mean Temp, of Equator. 



T T 



Eq. Temp.= ^r- 



* cos. 2 L. 



81°.37 

 79.43 

 82.97 



82.4 



Means, 81 .08 81 .56 



Mean of both, 81°.32. 



It follows, therefore, from the Batavian observations, that 

 the equatorial temperature is not beyond 81 J°. 

 The observations made at the Sandwich Islands in 1821, give, 



Mean Temp. 

 Hawaii, Lat. 19£° (See our last Number, p. 370.) 75°.l 



* See this Journal, vol. v. p. 269. 



t A correction of 24° i s added for altitude. 



