1842.] on the North-Western Frontier. 249 



such cases, the original seat of the disturbing forces must necessarily fall 

 short of the centre of the earth, and also be unconnected with any such 

 continuous fluid nucleus, as many suppose to exist at .no very great 

 distance from the surface. When from the action of any disturbing 

 cause, the equilibrium of a continuous fluid mass was deranged, the 

 resulting motions would be communicated in all directions radiating 

 from the point of original disturbance, and if this was near the centre of 

 the earth, the movements ought to affect its whole surface, so that 

 shocks would be experienced nearly simultaneously over the whole 

 world. But however extensive may be the connection of certain Earth- 

 quakes on record, we have nothing approaching to any such universali- 

 ty of effect as this, and the theory of local action (using this expression 

 in a large sense) appears to agree best with the present state of our 

 knowledge relative to the phenomena of Earthquakes and their causes. 



On the night of the 5th of March, 1 842, another very severe shock 

 was experienced, which appears to have been more limited in its range 

 than the preceding, and exhibited essentially distinct phenomena. The 

 motion in this instance, instead of being like the rounded swell of a 

 fluid or viscid mass, was sharp and sudden, like the effect of a concussion, 

 than of an undulation, and seemed indeed to be a much magnified •' jarr," 

 similar in kind to that experienced by the hand when a hammer held 

 by it, is struck forcibly on a hard unyielding body. One intelligent 

 friend, who was in his study when the shock occurred, described the 

 effect to be, as if he and his chair had received a sudden and severe 

 blow from behind, by which they were impelled forward, while to me, 

 it seemed as if my chair had been suddenly lifted from the ground, and 

 dashed down again with great force. 



The following interesting detail of the effects of the shock, as experi- 

 enced at Berkeri, a station on the Doab Canal, about 20 miles south 

 of Saharunpore, was communicated to me by Serjeant and Overseer 

 J. Petrie, to whom I feel much indebted for the trouble he has taken in 

 preparing it. 



Letter from Serjeant John Petrie, dated Berkeri, 5th March, 1842. 



Sir, — We had a very smart shock of an Earthquake here at 9 o'clock 

 this evening ; so much so indeed, that every thing in this bungalow 

 shook and rattled again. I had just laid down to rest with a book 



