1844.] Memoir on India n Earthquakes. 9 7 I 



1842, other examples of the rumbling noise accompanying shocks will 

 be found. 



2d. A rushing sound. In describing the shock of 2d July 1832, 

 (Part II.) Dr. McClelland remarks, " during twelve seconds the 

 earth shook or rather trembled, and afforded a noise which it is 

 difficult to describe, but which may be compared to the sound of a 

 heavy but transient rush of water: the noise preceded and sue 

 ceeded the motion about three seconds." Similar rushing sounds ac- 

 companied the shocks of the 23d September 1832, 30th May 1833, 

 and 4th January 1835. The Calcutta shock of the 11th November 

 1842, is described as having been accompanied by " a noise which at 

 first resembled a mighty rushing wind," and afterwards " the loud 

 rattling of carriages over a stony street;" the shock of the 19th June 

 1819, as felt at Chunar, " was accompanied by a noise in the atmos- 

 phere resembling the rapid flight of birds." 



These sounds always appear to be in the air, and although not inva- 

 riable accompaniments of earthquake shocks, are rarely wanting. The 

 movements of the crust of the earth must communicate similar move- 

 ment to the air, and hence give rise to sounds; but it must be con- 

 fessed that this cause is not sufficient to explain satisfactorily the loud 

 and sudden explosions, and the peculiar rushing or whizzing sounds, 

 that are so often observed ; explanatory evidence is not yet collected to 

 enable us to form a confident opinion, and although plausible specu- 

 lative causes might be stated, I prefer waiting for further information, 

 especially as among materials not yet arranged, there appear some 

 facts which may illustrate this subject. 



There is a notice of a sound observed during the Scinde earthquake 

 of 1819, which although merely incidental and far from specific, yet 

 merits remark. Under date the 25th June 1819, (Part II. p. 36,) 

 an observer at Porebunder states, " the late phenomena have brought 

 to my recollection, my having observed to an Officer of the Marines 

 about the beginning of March last, that there was a cloud in the north 

 east, which appeared uncommonly charged with electric matter; its 

 direction was nearly opposite to the one from which I heard the sound 

 that preceded the great shock of the 16th." It is perhaps rash to base 

 any inference on an isolated fact like this, but it leads me to suspect 



