METEOROLOGY. 973 



waves extend up to the limits of our atmospliere and are of cosmical 

 origin, then it is of tbe greatest importance that conditions in them at 

 high levels be observed. — h. a. iiazen. 



Droughts and famines in India, J. Eliot ( TJ. S. Dept. Agr., Weather 

 Bureau Bui. 11, pt. 2, Rpt. Tnternat. Meteorolog. Congress, 1893, pt. 2, pp. 

 444-459, pis. 2). — This is a most interesting and exhaustive treatment 

 of all the facts known regarding these terrible visitations. During 122 

 years there have been 17 famines. Statistics of the 8 intense famines 

 are given, with loss of life and property, or expenditure of money to 

 £^ive relief. 



The areas most liable to drought are chiefly in the tropical belt, 

 where the rains are periodic. Prolonged droughts are more frequent 

 in India than anywhere else in the world. The meteorologic features of 

 the Indian monsoon area may be divided into two periods — the north- 

 east monsoon of dry land winds, from January to May, and the southwest 

 monsoon of humid sea winds, from June to December. The southwest 

 monsoon air circulation is caused, at first, by the formation of a low 

 pressure area over northern India in April and May because of a rapid 

 rise in temperature. It is a breaking down of the southeast trades at 

 the equator and an adaptation of their circulation to the changed con- 

 ditions at the north. The maintenance of the new order is due to a 

 self-contained energy liberated by rainfall rather than to a continu- 

 ance of the hot weather conditions in the north. The greater part of 

 the rainfall of India (37 in., or 90 j)er cent.) occurs during this southwest 

 monsoon. Just before this wind begins northern India is one of the hot- 

 test and driest areas in the world. Occasionally maximum shade 

 temperatures of 120° and 124° are registered. The relative humidity 

 often falls below 20 per cent, and 1 per cent has been recorded. The 

 variation of rainfall is greater than in any other country. In Sinde 

 the average is 5 in. jier year, and in the Khasia Hills there are 500 in., 

 which is the greatest in the world. The range from year to year is 

 very great ; at Kurrachi, 0.47 in. in 1872, and 28 in. in 18C9 ; at Jacobabad 

 in 36 years, least 0.72, greatest 12.05 in. 



There are three zones of rainfall in India : (1) The arid zone, with less 

 than 15 in. rain in a year. Here cultivation is dependent on irrigation 

 and there are practically no famines. (2) The dry zone, with 15 to 35 

 in. of rain. Rain sufficient in average years, but prolonged drought 

 leads to great scarcity. (3) The moist zone, with rain 35 to 500 in. 

 It is a singular fact that the rain is most variable where it is smallest 

 in amount and most regular where it is greatest; hence this zone has 

 no famines. 



Favorable conditions for crops are as follows : (1) For cold weather 

 crops (wheat, barley, pulse, etc.) a moderate rain in October, to fit the 

 ground for plowing and in order that the moisture may germinate the 

 seed. Occasional light showers, more especially on the higher lands, 

 in order to develop the grain. (2) For hot weather crops of rice, heavy 

 I)urst of rain for planting, moderate rain during growth, and a burst 



