and especialli/ in Scotland. 261 



very fitly represented by the term " tremblement de terre*^ em- 

 ployed by the French. A gentleman who has felt several of 

 the Perthshire earthquakes has stated to the author, that the 

 more severe shocks gave him a sensation very similar to that of 

 a person riding, when the horse shakes himself. 



In illustration of this tremulous motion of the earth, when 

 under the influence of a shock, reference may be made to the 

 entry in the registry under date 5th November 1789, where it 

 is noticed, that '* there was a tremulous motion, which made 

 the flames of candles vibrate and furniture clatter." Under 

 date August 1786, it is mentioned, that the slates rattled on 

 the roof of a house, and the strings of a spinet emitted a mu- 

 sical sound. During the shock of 8th February 1750, the trees 

 near London are said to have '* quivered." 



The other sensation above alluded to, as illustrating the 

 nature of earthquake-shocks, is that produced by a violent 

 blow or concussion. This does not appear to be perceived in 

 all cases. The tremulous or trembling motion is always per- 

 ceived. When the blow occurs, it is generally in the midst of 

 the tremors, and at the moment that they are the most intense; 

 and accompanied with the loudest noise. This blow or con- 

 cussion is so well known in Strathearn, that it has obtained 

 from the country people there a particular name ; they call it 

 the " thud." Its character and effects seem to be well de- 

 scribed, under dates 5th and 11th November 1789. The shock 

 felt on the first of these dates, gave the sensation as if the 

 foundations of the houses had been struck by an immense 

 mallet : — the shock on the second date, shivered to pieces the 

 ice on a lake near Lawers House. Under dates 8th March 1750, 

 September 1833, and March 1839, it is noticed, that blows 

 were felt to be received by boats on their bottoms, as if they 

 had struck on rocks. By the first mentioned of these shocks, 

 fish were forced to leap three feet out of the water — probably 

 from the pain caused by the concussion. 



Since notice has been taken of the Lisbon earthquake of 

 1755 in the register (on account of its eff'ects in this country), 

 it may be mentioned, in further illustration of the point now 

 adverted tQj that h ship off Cape St Vincent, at the time of it3 



