366 



C. Davison — British Earthquakes of 1889. 



The disturbed area is thus roughly elliptical ; its longer axis, in 

 a direction about N. 30° E. and S. 30° W„ being about 25 miles 

 long, and the shorter axis about 18 miles. The whole area disturbed, 

 including that covered by the sea, is about 350 square miles. The 

 boundary of the disturbed area corresponds to an isoseismal line of 

 intensity IV. 



Nature of the Shoch. — From the few records I possess on this 

 point, it would seem that the shock consisted of only one vibration ; 

 no tremulous motion, either before or after the shock, being noticed 

 at any place. 



Duration. — The estimates of the duration are fairly concordant. 

 It is stated to have been not more than two to three seconds at 

 Glen Saddell ; several seconds at Kilberry ; two seconds, or perhaps 

 more, at Lochranza; and not more than four or five seconds at 

 Gigha. But, as there was only one vibration noticed, it is probable 

 that these estimates include also the duration of the sound that 

 accompanied the shock. 



^M^i^reJBca^&iquaJt^ •• Jahf 75J689* 



Intensity. — At Lochranza, the intensity must have been Y. or 

 nearly so. It was probably greater than lY. at Killean ; and lY. 

 at Glen Saddell, Kilberry, Clachan, and Gigha. 



Sound- Phenomena. — So far as I can learn, the sound-area was 

 approximately co-extensive with the disturbed area considered as 

 bounded, as above stated, by an isoseismal of intensity lY. From 

 Ardpatrick and Tarbert I have no particulars beyond the fact that 



