04 Address. [Feb. 



tliat there were two balloon ascents made in Calcutta in the year 1889, 

 and tlie observations made on these occasions point to the fact that 

 extremely valuable information might be obtained from a series of 

 such ascents. 



" It is well known that during the hot- weather months, Bengal forms 

 a kind of focus to which three converging wind systems blow. There is 

 the north-westerly current, blowing down the Gangetic valley, which 

 spreads over Behar, parts of Chutia Nagpur &c. ; the second is an 

 easterly current blowing down the Assam valley, and the third is the 

 strong southerly current which blows at the head of the Bay of Bengal, 

 and for some distance inland. The strength of these southerly winds, 

 as judged by the wind velocity, is greater in the hot- weather months, 

 when very little rain is brought up by them, than it is in the actual 

 soutli-west monsoon season, when, as is well-known, extremely heavy 

 rain is brought up by the southerly current. It has been surmised that 

 the southerly winds of the hot- weather months are confined to a shallow 

 belt near the eartli's surface and do not extend to considerable altitudes 

 like the south-west monsoon current, and hence, though strong on the 

 surface of the land, they do not penetrate far into the interior of the 

 province of Bengal. 



" On the first occasion when Mr. Spencer ascended in his balloon, on 

 19th March 1889, from the Calcutta Maidan, there was a moderate south 

 south-westei'ly wind blowing near the surface. The balloon was at first 

 carried rapidly towards the north-north-east, slowly rising also in its 

 course. When the balloon, so far as could be judged, was about 1,500 to 

 2,000 feet high, it ceased to have any northerly movement, and shortly 

 afterwards drifted very rapidly in a south-easterly direction, proving 

 clearly that there was a strong north-westerly wind-current blowing 

 only a short distance above the earth's surface, say at an altitude of 

 2,000 to 2,500 feet, notwithstanding the strong southerly current blowing 

 below it. 



The second balloon ascent was made by Mr. Spencer accompanied by 

 Lieut. H. J. Coninghani, who very kindly consented to take a series of 

 meteorological observations which will be published in the Report of 

 the Meteorology of India for 1883. Mr. Coningham writes in connec- 

 tion with the direction of winds experienced in this ascent as follows : — 



" The balloon started with an almost direct southerly wind (i. e., 

 south to north), and continued in this direction until an altitude of 

 about 3,500 feet was reached, when there was a tendency for the balloon 

 to go towards the south-south-east, and above this height there was 

 a north-north-westerly wind blowing ; but on coming near the earth 

 again (about 2,800 feet), the balloon took a north-westerly course, 



