1842.] A Sixth Memoir on the Law of Storms in India. 717 



A third phenomenon is the very remarkable and dangerous one of 

 a terrific tempest like that of the Ariel, without any corresponding 

 depression of the Barometer or Simpiesometer. It is possible, however, 

 that if this last instrument was not very carefully watched, it might 

 have been oscillating, though not upon the whole falling, before the 

 storm came on. Still the possibility of such a circumstance should 

 warn the seaman to neglect no precaution. 



My last practical remark refers to the highly serious danger arising 

 from the current, or " storm wave," which seems to prevail in some of 

 these tempests as far South as the Paracels, setting generally, it would 

 appear, to the Westward, though in the case of the General Harris 

 and General Kyd to the N. E. The logs of the London, p. 607, 

 Warley, p. 612, Scaleby Castle, p. 628 and 632, and Castle Huntley, p. 

 651, afford ample proofs of this dangerous current ; and I may mention in 

 corroboration, that I have, in original documents and replies to a num- 

 ber of circulars addressed by me to the gentlemen of the H. C. Pilot 

 service, at the mouth of the Hooghly, indubitable proof, that a current 

 of the same kind running from two to five knots an hour, sets over the 

 tails of the reefs to the Westward, in the Easterly and North-easterly 

 hurricanes, at the head of the Bay of Bengal;* besides much evidence 

 to shew, that the devastating inundations which occur along the Coast 

 from the Megna to Coringa, are often caused by a true storm- wave 

 breaking in suddenly, and sweeping every thing before it. 



From the imperfect accounts which reach us from China, we may 

 also I think gather, that something of the same kind occurs there. 



Before I conclude, I must allude, as a question for research only, to 

 another remarkable feature in these tracks, and indeed all the storm 

 tracks we have yet traced out ; which is this : If we look at the chart, 

 we shall see that almost the whole of the storms seem to come in groups 

 from certain quarters, and these quarters are those in which active or 

 half-extinct volcanoes are situated. 



Considering our chart in this view of the subject, we shall observe 

 that, to commence from the Northward, six tracks, Nos. XXIX to XX 

 appear to come from the North-eastward, or from the direction of the 



* These will be published as soon as I can complete my Memoir on the Storms of 

 the Sand Heads, and that on the (old) Storms of the Bay of Bengal. 



5 B 



