The Philippine Islands and Their People 101 



pines on their westward course and turn 

 north in the China Sea. 



Their origin is probably in the region 

 where the trade wind, blowing con- 

 stantly from the eastward, meets the 

 southwest monsoon. It may be by con- 

 flict between these two opposing air cur- 

 rents in this region that the whirl is set 



ter, and violence the so-called West 

 India hurricanes. They are of frequent 

 occurrence, often following one another 

 closely, at intervals of but a few days, 

 and many of them have been very vio- 

 lent and destructive. 



The rainfall pf the archipelago closely 

 follows the winds. The general modus' 



Nipa House Under Construction 



Photo by Gannett 



up. At first this whirl travels in the 

 course of the trades, as they are the 

 dominant wind, but as it goes westward 

 the influence of the monsoon becomes 

 relatively the stronger, and the typhoon 

 yields to it and passes off in its direction 

 to the northeast. Hence the monsoon 

 season is the season of typhoons. 



Typhoons resemble in course, charac- 



operandi of rain-making is very simple 

 and scarcely needs repetition here. Air 

 coming off the sea is always and every- 

 where practically saturated with moist- 

 ure. On reaching the land, if the latter 

 is colder than the sea, and therefore 

 colder than the air currents, which have- 

 the temperature of the sea, it is chilled, 

 and hence, unable to hold in solution so- 



