66 Dr Brewster 07i the Mean Temperature of the Equator. 

 Hence the mean annual temperature for 1823 is 79°.87 



Mean of these, 79° 18 



Observed mean annual temperature of Prince of 

 Wales's Island from three years observation. 



Do. calculated by my formula of T = 81°.8 



sin. D + 1 - - - 79 93 



Difference, 0° 75 



From these calculations it appears that the mean tempera- 

 ture of three different points of the Malay Peninsula is lower 

 than that which is deduced from formulae founded upon 

 Humboldt*'s estimate of the equatorial temperature. As we do 

 not know the altitude of the places of observation, a slight in- 

 crease must be made in reducing them to the level of the sea ; 

 but this is too small to alter in any way the general conclusion 

 which the observations authorize. 



If we now deduce from the same observations the mean tem- 

 perature of the equator by means of the formula. 



T 

 Equatorial temperature = — . - we shall have 



Mean temp, of equator from Singapore observations 80° 03 



Malacca do. 78 71 



Prince of Wales do. 79 53 



Mean temperature of the equator, 7^° ^^ 



Hence it follows that the mean equatorial temperature is 

 considerably less when deduced from the observations made in 

 the Malay Peninsula, than when it is deduced from the obser- 

 vations in Ceylon, Batavia, and Hawai, as the following table 

 shows. 



