and especially in Scotland. 139 



mitted best where the strata were solid and continuous. The 

 primitive and igneous rocks, forming continuous ranges of hills, 

 running NE. and SW., would facilitate the transmission of 

 the shocks in these directions, — whilst the secondary forma- 

 tions deposited on the sides of these mountain-chains, would 

 obstruct the transmission in opposite directions. 



4. The shock was produced by a nwcement of the ground, 

 which, in some places, especially near Comrie, consisted of 

 several distinct and successive undulations, followed by a ge- 

 neral quavering, " shuddering," or tremblement de terre^ but 

 in more distant places, of a tremblement only. 



Eight of the accounts before given bear, that the shock 

 consisted of two undulations, each accompanied by a loud re- 

 port or subterranean explosion. Six other accounts bear, that 

 there were three undulations. There is one which bears, that 

 as many Sisfour distinct rockings were perceived. 



The height to which the earth's surface appeared to be 

 raised by the shock, was attempted to be estimated by some in- 

 dividuals, — though only of course as matter of impression or con- 

 jecture. Thus, itwas thought, bypersons at Comrie who felt the 

 shock, that the ground was elevated 6 or 8 inches ; and in the 

 Carse of Falkirk, 4 or 5 inches. At Callendar, Dr Fogo thought 

 the house was raised " with a violent jerk, 6 or 8 inches from 

 the ground." Dr Stein of Menstrie, near Alloa, says, that his 

 servant thought the kitchen was lifted " up from 2 to 3 inches.'.' 



The angle made by the wave with the horizon, appeared to 

 be at Alloa 1" 18', and in the Carse of Falkirk 3° 47'. If, as 

 an average, the wave is supposed to have been 5 inches high 

 at its apex, and to have sloped on its anterior and posterior 

 surfaces at an angle of 2^ degrees to the horizon, the breadth 

 or base of the wave would have been rather less than 20 feet. 

 But the observations from which these results are deduced, 

 were so few and so casual, that no great value can be attached 

 to them. 



That there were undulations formed by the shock, is indu- 

 bitable. On this point at least, full reliance may be placed on 

 the concurrent sensations of numbers of individuals, several of 

 them experienced naval officers, who attest the factof there hav- 



