FROST NOT CONTINUOUS. 33 



a very elaborate and apparently carefully kept 

 register on board the Mahatnoodie, at Ngo-tsoo, in 

 1844, the annual mean temperature was 69 T 7 o° ; the 

 lowest temperature marked being 49° 5', and the 

 highest 90°. 



The preceding accounts are sufficient to show, 

 that severe frost and occasional snow prevail in the 

 tea districts ; and on some occasions, though rare, 

 so late as the vernal equinox. Yet there is reason 

 to believe, on an average of seasons, that the frost 

 is not very intense, or of long duration. Ice the 

 thickness of an inch does not indicate great severity 

 of cold, or long continuous frost. In these lati- 

 tudes, from 27° to 31°, it must be remembered that 

 the sun, as well from its direct influence as from 

 the frequently unclouded state of the atmosphere, 

 has great power in the winter season ; so that in 

 the central provinces of the empire there is much 

 reason to believe that the frost, though occasionally 

 intense, is not sufficiently continuous to allow ice 

 of great thickness to form under the influence of 

 so powerful a sun : nor is the monsoon inland and 

 along the coast so steady but that the wind often 

 veers to the south, and brings with it compara- 

 tively warm damp weather, and rain. 



Nevertheless it is now known that ice-houses of 

 very simple and efficient construction are formed 

 at Chusan and elsewhere. Ice is also collected 

 every year at the city of Nan-king, lat. 32° 4' 

 30", in sufficient quantity for the purpose of 



D 



