250 REGULARITY OF ADVANCE OF MONSOON AL RAINS. 



to be seen in any part of the world. According to 

 the late Captain Maury, U.S.N., they blow over the 

 whole expanse of space that lies between Africa and 

 the Philippine Islands. It would, however, be too long 

 to attempt anything like a detailed description of them 

 here. The average rate of travel, during the "back- 

 ing down" to the southwards of the S.W. Monsoon, 

 may be set down as from fifteen to twenty miles a 

 day, and the march of these great air waves thus 

 proceeds under normal conditions, with almost as great 

 regularity as that of a railway train moving from point 

 to point, according to time table. Monsoons may be 

 regarded as simply deflected trade winds. Throughout 

 the vast expanse mentioned above, as Captain Maury 

 explains, 



"The N.E. trades are called N.E. Monsoons, because in- 

 stead of blowing from that quarter for twelve months, as in 

 other seas, they blow only for six. During the remaining 

 six months they are turned back, as it were ; for instead of 

 blowing towards the equator, they blow away from it, and 

 instead of N.E. trades, we have S.W. Monsoons." * 



The season of the tropical rains is everywhere more 

 or less synchronous with the passing of the sun in the 

 zenith : for the great luminary of the day is the hered- 

 itary keeper of the floodgates of heaven; as the sun 

 proceeds north or south from the equator he opens 

 them : the life-giving water descends, and the earth 

 gives forth her increase. As the sun returns, and 

 recrosses the zenith, on his journey back to the equator, 

 he closes them again: presently the rains cease; the 



* The Physical Geography of the Sea, by M. F. Maury, late U.S.N., 

 i6th edit., 1877, pp. 36566. 



