Dr. C. Davison — British Earthquakes, 1893-99. 113 



this case, as the earthquake appears to be unique in one respect 

 among British earthquakes of the last eleven years. 



So far as the accounts may be trusted, the disturbed area appears 

 to consist of two detached portions — one in the neighbourhood of 

 Fort William, the other in Moidart and Arisaig in the extreme west 

 of Inverness-shire. Eleven of the places of observation lie in the 

 former area and three in the latter, while between them there are 

 three places (Kinlochiel, Duisky, and Kingaivloch) at which, I am 

 told, the earthquake was not observed. Much reliance should not of 

 course be placed on so small a number of negative records, especially 

 for an earthquake which occurred at midnight ; but there is also 

 distinct evidence that, in the eastern area, the shock was much 

 weaker on the west than on the east side of Loch Linnhe. 



In a country district, time-records are naturally liable to con- 

 siderable error, but those in both parts of the disturbed area agree 

 in giving the time as nearly midnight. If there were two separate 

 impulses, there is therefore no evidence to tell us which occurred 

 first. 



Of the places in the eastern area, four (Ardgour, Banavie, 

 Carpach, and Trislaig) are on the north-west side of or close to the 

 great Highland fault, and the remaining seven (Achintore, Blarmac- 

 foldach, Carnach, Fort William, Gleucoe, Nether Lochaber Manse, 

 and North Ballachulish) are on the south-east side. The boundary of 

 the area cannot be determined satisfactorily from these places, but 

 it is about 17 miles long, its longer axis is roughly parallel to the 

 great fault, and it extends to a much greater distance on the south- 

 east than on the north-west side of the fault. If the shock felt 

 in the eastern area were due to a slip of the fault, or of one of 

 the system of faults, it is clear that the fault concerned must hade to 

 the south-east. This is also shown by the intensity of the shock; 

 for the only places where it attained the degree 4: (Blarmacfoldach, 

 Carnach, and Nether Lochaber) are on this side. 



As a rule, the shock resembled the tremors felt in a house when 

 a heavy conveyance is passing. At Nether Lochaber Manse, how- 

 ever, the movement was stronger and more distinct, being like that 

 felt in a heavy carriage in rapid motion on a rough road, and 

 culminating in a severe vibration. The sound was compared by 

 three observers to the rumbling of a cart or a heavy loaded waggon 

 on a rough road, and by three to distant thunder. 



Very little can be ascertained with regard to the western part of 

 the disturbed area. The shock was felt only at three places, namely, 

 Arisaig, Glenmoidart, and Roshven ; at the second of these places 

 the intensity was 4. The sound was described by one observer as 

 like distant thunder, and by another as like the explosion of a large 

 quantity of gunpowder at a great distance. The observer at 

 Glenmoidart informs me that a second and weaker shock was felt 

 there in the daytime some days afterwards, and a third at night. 



It seems to me probable from the above evidence that there were 

 two distinct shocks, each disturbing a separate area ; and that the 

 shock felt in the neighbourhood of Fort William was due to a slip of 



DECADE IT.— VOL Til.— NO. III. 8 



