Cuar. XV.] RAINS.—WET AND DRY SEASONS. 287 
months in the year are those near the change of 
the monsoons, in May and June, and again in Sep- 
tember, when the rains fall in torrents, probably 
owing to the stagnation produced in the atmosphere 
by the change in the direction of the winds. 
The author before quoted explains this on the 
following principles. He says: —‘‘ The north-east 
monsoon, which commences about September, blows 
strongest during the above period, and begins to 
yield to the opposite monsoon in March. About 
that time the southerly winds come charged with 
the moisture which they have acquired in their 
passage over the sea through warm latitudes; and 
this moisture is suddenly condensed into thick fogs 
as it comes in contact with the land of China, 
which has been cooled down to a low temperature 
by the long-continued northerly winds. The latent 
heat given out, by the rapid distillation of this 
steam into fluid, produces the sudden advance of 
temperature which takes place about March ; and 
its effect is immediately perceptible in the stimulus 
given to vegetation of all kinds, by this union of 
warmth with moisture. With the progressive 
increase of heat and evaporation those rains com- 
mence, which tend so greatly to mitigate the 
effects of the sun’s rays in tropical climates. In 
the month of May the fall of rain has been known 
to exceed twenty inches, being more than a fourth 
of all the year, and this keeps down the tempera- 
ture to the moderate average marked for that 
month.” 
