Chemistry and Physics. 233 
year, there is scarcely any difference at all between the months. 
Somewhat to the south of the equator, where to the difference in 
the nearness of the sun is added a much greater height above the 
horizon in January, we have—- 
January. July. Rainy Season. 
Amboina, Molucca Islands, 4° S. 80°-9 77-4 May to August. 
Batavia, Java, 6° S. T7°-4 78°°8 December to February. 
Pernambuco, Brazil, 8° S. 80°°6 75°°0 il to July. 
80, by the first-rate observations of Batavia, it is established that, 
so far as 6°S., January is 1°*1 colder than J uly, because the former 
18 very rainy, while the latter has little rain. Even to 9° lat. N., 
July is colder than January, if the former has much more rain, 
so for example—— 
rnando Po, W. Africa, 4° N. 79°-9 76°-5 March to November. 
Gondokoro, Upper Nile, 5° N. S108 75°-7 April to August. 
eetown, W. Africa, 84° N. 80°°4 77°-0 June to October. 
Thu 
find differences amounting to 5°-6, while in the southern greater 
differences than 1°*1 are not known, which may, to a certain 
and a few degrees north and south from it, far more influenced 
, di 
sive to the higher strata a superior temperature than that they 
had in the dry season; in other words, the decrease of tempera- 
rains than in the 
nford is is 
temperature of the equator. The extent of the tropical zone is so 
rth Canton, 55°-6, Victoria, Hong-Kong, 59°°2. t Saigon, in 
chin China, but 11° to the south of Hong-Kong, and subjecte 
