1090 A Seventh Memoir on the Law of Storms in India. [No. 131. 



Amooah may be considered as situated at the foot of the glacis, 

 which descends from the secondary ranges of the Himalayas, and at 

 a point about which the circular storms from Calcutta upwards, and 

 the gale blowing from the Eastward along the foot of the hills may 

 have met, and thus have occasioned the " whirling about" noticed in 

 the report. 



The most remarkable of the results of our enquiries is the explana- 

 tion which is afforded us, by the clear and exact reports from Soora- 

 jegunge and Bhaugulpore, and by the curious accounts of the 

 whirling and driving about of the clouds at Gya and Amooah of a 

 phenomenon which is often puzzling to account for ; that of " winds 

 continually veering," which happens so often in furious tempests, not 

 only at the centre, where it may well be looked for, but also at the 

 circumference of storms. It is clear, or at least in the highest degree 

 probable, that this arises from the interference of two storms, the cur- 

 rents of which, perhaps variously affected in their course, meet at certain 

 points, and thus cause the continued veering or vibrating of the wind. 

 In the present memoir, we have in the log of the Algerine, at p. 978, 

 an instance of this occurring at sea, which may have been the effect of 

 the monsoon, and on shore at Monghyr, and at the factory on the 

 banks of the Jaboona, at which places, as to the two last, we know, 

 that this cause existed.* 



I have adverted, p 1087, to the influence which the Cachar hills, (the 

 ranges to the Eastward of Dacca,) may have had upon the Sooraje- 

 gunge storm, but there is another consideration to be borne in mind 

 here, which is, that both from the effect of the S. W. monsoon, as well as 

 that of the storm, the winds would necessarily become more Southerly 

 along the Eastern limits of the plains, which for our purpose we may take 

 to be marked by the course of the Burrampooter to lat. 26° N., and 

 more Westerly along the foot of the Eastern and Western ranges of the 

 Nepal hills, or parallel to the line of the stations of Rungpore, Dinaje- 

 pore, and Purneah. We may indeed, from Dacca to Purneah, consider 



* Supposing their cause to have operated with less intensity, and in more time as 

 at the circumferences of great circles of 500 or 1000 miles in diameter, we should 

 probably have the same phsenomenon, then called " variable winds, with a cross swell 

 for the last 48 hours," which we so frequently meet with in Log books. See also Col. 

 Reid's Chapter V. on Variable Winds. 





