DISCUSSION AND ANALYSIS OP WINDS. 



737 



Indian Ocean, IOO-I50 S. 

 " 5 -10 S. 



" -5 S. 



" -5 N. 



" 5 -10 N. 



'■ 10 -15 N. 



40O_45O E. 

 45 -50 E. 

 45 -55 E. 

 40 -50 E. 

 40 -60 E. 

 50 -60 E. 



June to August. 



0.5 

 O.I 



0[ 

 0-3, 0.3 



2| 3 



December to Fcbruiiry. 



Here the S. E. trades prevail S. of 5° S.; between 0° and 5^ S. there is a zone of vari- 

 able winds, where S. E., S., S. W. and W. are most frequent, and north of the equa- 

 tor the S. W. monsoon is well established. From December to February the N. E. 

 trades have an easterly direction between 10° and 15° N. They become more N. E. 

 between 0° and 10° N., and between 5° and 10° S , N. W. winds are already pre- 

 vailing. 



Below the percentage of winds at some stations of India is given : — 





June to August. 



December to January. 



a; 





, 



pfl 





^' 



6 

 13 



7 

 8 



0.7 

 15 

 47 

 47 

 23 

 17 

 32 



2 

 11 



10 

 15 



4 

 13 

 7 

 5 

 12 

 66 



37 



7 

 8 

 2 



21 



2 

 28 

 25 

 11 

 11 

 IS 



i4 



S5 



8 

 7 

 7 

 5 



24 



8 

 19 

 15 

 45 



20 

 58 



7 

 8 

 6 

 6 



3 



9 

 10 



7 

 20 

 29 



4 



3 

 11 

 11 

 17 



10 



4 



2 



1-5 



13 



29 



6 



15 

 6 

 4 

 3 



4 

 11 



0.4 



0.3 



4 



9 



2 



7 



9 



5 



13 



15 



24 



1 



0.7 

 2 

 1 

 4 



12 

 28 

 19 

 13 



2 

 22 



6 

 6 

 0.6 

 

 2 



& 



12 

 24 

 41 

 43 



21 



20 

 43 

 44 

 4 

 1 

 6 



Zone 14. N. 36. Calcutta 

 " 13. N. 86. N. Central India . 

 " 13. N. 84. Baroilly, Central India . 

 " 13. N. 80. Eoorkee .... 

 N. W. India- 

 Zone 12. N. 185(a). Moultan 

 " 12. N. 188(6). LodianahandDehraDoon 

 Zone 15. N. 35. Bombay, number of obs. 



. number of miles . 



" IG. N. 36. Madras 



N. 34. Dodabetta, 8640ft., Neilgherries 

 " 17. N. 38. Colombo, Ceylon . 



5 

 4 



7 

 2 



8 

 4 

 0.7 

 0.3 

 1 

 9 

 



5 

 9 

 7 

 7 



11 

 7 

 0.9 

 0.4 

 1 

 3 

 



14 



21 



20 



7 



3 



18 



1 



0.8 

 2 

 2 

 



17 

 26 

 38 

 50 



6 

 17 

 4 

 4 

 14 

 1 

 1 



36 



8 

 5 

 5 



17 

 7 

 6 

 7 



14 

 

 3 



15 

 8 

 5 

 6 



50 

 19 



33 

 36 

 33 



63 



There is less regularity in the winds of India, taken as a whole, than in Eastern 

 Asia. Especially this is the case if we expect the summer monsoon to be every- 

 Avhere S. W., and that of winter everywhere N. E. without regard to the position 

 of the station towards the region of lowest pressure, and towards the ocean.' 



At Calcutta the monsoons must be N. and S., as the region of lowest pressure lies 

 to the N. W. of this place, somewhere in the Punjab, as seen on Plate 14. In the 

 N. W. provinces of India the winds of summer are rather S. E., while N. W. and W. 

 winds prevail in winter. The latter is a current of air from the interior of the penin- 

 sula towards the sea, and has much in common with the N. W. winds of Eastern 

 Asia. Farther to the N. W. at Lodianah and Dehra-Doon, we are nearly out of the 

 monsoon region. According to Blanford the winter winds begin on the plains of 

 Northern India, where the pressure is high at that season. They flow towards the 

 seas to the S. W. and S. E. 



At Bombay there is a very slight change in the direction of the prevailing wind. 



' M. Blanford has well discussed the monsoons of Bengal and the adjoining provinces, and their 

 relation to pressure, in " Reports of the Meteorol. Reporter of the Govt, of Bengal." 

 93 July, 1875. 



