S74 Mr D. Milne on Earthquake-Shocks in Great JSritam, 



ward to this distance at least ; and that the candelabra, by its 

 inertia, was left behind. 



With the foregoing proofs, that the earth's surface with 

 every successive shock is made to undulate more or less, there 

 is no reason to disbelieve the accounts of sensations of sea- 

 sickness, which are said to have been frequently experienced 

 during earthquakes. Sir Thomas Lauder, in his account of 

 the Inverness earthquake of August 1816, alludes to these 

 sensations ; and there are many other cases in which the same 

 thing was perceived, though it was not necessary to mention 

 them in the register. During the undulations of the ground at 

 Gibraltar, produced by the Lisbon earthquake, " most people 

 were seized with giddiness and sickness, and some fell down ; 

 others were stupified, though many that were walking or rid- 

 ing felt no motion, but were sick.* 



(4.) The motion produced by the shocks, seems to be more 

 felt in certain positions and situations than in others. The 

 statement just referred to as to the shock at Gibraltar having 

 been felt least by persons walking and riding, is corroborated 

 by the statement in the register, that the shock of 30th Sep- 

 tember 1750 in Derbyshire, " was scarcely perceived by per- 

 sons walking — more by those standing — and most of all by 

 persons sitting ; and perceived more in the upper storeys of 

 houses than in the lower storeys and cellars." Obviously 

 the undulations must be best felt by those who are at the time 

 most in contact with the ground ; and the upper storeys of 

 houses, and the tops of steeples, must be moved more than the 

 parts of the buildings next the ground, in the same way that, 

 when a vessel rises over a wave, the top of its mast moves 

 over a greater arc than the hull. 



If reference is made to the notices under dates 8th March 

 1750, 6th November 1764, and 13th August 1815, it will be 

 seen that alluvial places were always the most convulsed. 

 These cases are strongly confirmed by the fact, that the earth- 

 quakes of 1st November 1755 and 31st March 1761 produced 

 effects more remarkable in Holland, than in places much 



* Discourses on Earthquakes, p. 322. 



