396 DR. CHARLES DAVISON ON THE [Aug. 1902, 
and another not much, if at all, weaker, it is clear that, if they had 
been due to slips along the boundary-fault, they could not have 
escaped notice by one or more of the watchful observers at Doch- 
garroch, Dores, Drumnadrochit, Holm, and Inverness. They must 
therefore have been of local origin. Mr. 8. Archibald, to whose 
careful observations and enquiries we are indebted for the know- 
ledge of these after-shocks, informs me that he has on several 
previous occasions heard mysterious rumbling noises at Dalarossie ; 
but the occurrence of the recent shocks and sounds in such close 
succession to the principal Inverness earthquake shows, I think, 
that the great slip on September 18th was responsible for the 
precipitation of the movements in the Findhorn Valley.! 
Conclusion.—The region which les between Loch Ness and 
the sea appears to be in a stage of more rapid development than any 
other in the British Islands. In all probability, the earthquakes of 
1816, 1888, and 1890 originated within it, as well as many of 
the minor shocks that followed them. That the earthquake 
of August 13th, 1816, was the strongest of the series is evident 
from the damage which it caused to buildings in Inverness and from 
the large area that it disturbed. Its series of after-shocks, of which 
no doubt only the more important were recorded, lasted until 
November 10th, 1818; and it is worthy of notice that, so far as 
we can judge frem the scanty materials that have come down to us, 
the foci of some of these after-shocks lay beneath the north-eastern 
end of Loch Ness. The earthquake of February 2nd, 1888, was 
probably also attended by a train of after-shocks; but no accounts 
of them seem to have been published. After the earthquake 
of November 15th, 1890, the foci of the minor shocks showed 
a tendency, though with some oscillations, to recede in a south- 
westerly direction towards Loch Ness ; while in 1901 this tendency, 
as we have seen, was revealed in a very striking manner. 
The earthquakes provide no evidence with regard to the direction 
of the displacement along the boundary-fault ; they do not tell us 
whether the rock on the south-east side of the fault was elevated 
or depressed with reference to that on the north-west side. There 
can be little doubt, however, that Loch Ness is still growing ; but, 
without instrumental observations continued for many years, it can 
hardly be decided whether the lake is now contracting in area, 
or whether it is gradually, though very slowly, pushing its way 
outward to the sea. 
1 The shock and sounds observed at Teanassie on feptember 22nd, and 
Aigas on September 29th, may have had a similar origin. These places are 
both 8 miles to the north-west of the boundary-fault. 
Immediately after the Japanese earthquake of 1891, there was a great and 
sudden increase of seismic activity in two detached regions, one 45 miles north- 
east, and the other 55 miles south-west of the meizoseismal area. See Geol. 
Mag. 1897, pp. 23-27 & Geogr. Journ, vol. xvii (1901) p. 653. 
