1052 Third Memoir with reference to [No. 106. 



But in both cases, the great distance travelled is that between the 

 2Sth and 29th. We cannot be far wrong in assuming this as correctly 

 laid down, I think, when we look at the carefulness of the logs, and the 

 remarkable rapidity with which the storm reached and passed some 

 of the vessels? We may therefore take it as an instance of a storm in 

 the Bay which, for this part of its track, — 2Sth to 29th, — travelled 350 

 miles in 24 hours ; or something more than 14^ miles per hour ! Why 

 did it travel so slowly again, from the 29th to the ZOth f 



We must take the vortex of the 2Sth and 29th to have been at the 

 surface of the ocean, and, for any height with which we have to do, 

 call it an aerial column of, say, 250 miles in diameter. Such a volume of 

 displaced air, moving with such a velocity, must necessarily be felt at 

 some distance preceding the line of its track. It meets as it approach- 

 es the coast with one direct obstacle, nearly at right angles to its 

 course — the Coromandel range, and with the deflecting force of the S W. 

 monsoon, which the Elephanta, we see, is bringing up along the coasts 

 Whether these are the causes, or whether they are sufficient .ones, I 

 cannot presume to decide ; they appear to me to be probable ones at 

 least, and to account fairly enough for the decreased rate of progress 

 and change of direction. The tracks perhaps should be laid down in 

 curves, and not in straight lines? The facility of tracing these last, and 

 of bringing them to fixed points at noon, have made me prefer the form 

 of straight' lined tracks, in this and my former Memoirs, to curved ones. 



On the 29th, the centre of the storm was 150 miles from the coast, 

 and we may say that it was 180 miles from the first considerable 

 range of hills ; so that taking it, as is seen in the diagram, to be 260 

 miles in diameter, or 1 30 in radius, the aerial wave, which preceded it, 

 was just about impinging on the hills at noon. How soon the re-action of 

 this on the vortex was felt, we have no means of judging. The NE. 

 wind experienced by the Elephanta on this day, when she is just on 

 the outer verge of the storm, and which it will be noted is against the 

 coast wind which she was bringing up, seems to be an effect of this 

 atmospheric disturbance; as the *^ heavy North-easterly swelV^ of the 

 30^^ evidently is of that of the storm ; the aerial wave having thus 

 preceded the aquatic one by about 24 hours. 



In tracing this storm farther inland, we have first the report from 

 Chuprah, in Lat. 25° 46' N. Long. 84° 46' E. bearing about N. 8° W. 

 228 miles from the spot where I have placed the centre on the \st 



