1888.] Mr Stevenson on the Recent Earthquahe in Scotland. 263 
The area over which it was felt is shown on the accompanying 
map, Plate V., and measures about 15,000 square miles. 
At Inverness, Ardnamurchan, and Oronsay the shock seems to 
have been distinctly of a vertical character, and at many places an 
undulatory motion was experienced, the direction in most cases being 
stated to have been roughly at right angles to the line of the Great 
Glen. Two or more waves in quick succession are reported from 
Kyleakin, Grantown, Port Augustus, Dufftown, Strathpeffer, Perth, 
Oban, and Falkirk ; but at Dalwhinnie a shock is reported one and 
a half minute after the first. The duration of the shock at Inver- 
ness seems to have been at least two seconds, the average of all 
observations at a greater distance from the centre of disturbance 
being about four seconds. 
The earthquake was in all probability due to a rupture of the 
crust of the earth or slip of the strata in the Great Glen, probably 
of some length, at or near Loch Ness at about 5.1, Greenwich time, 
and seems to have spread out at a speed of about fourteen miles per 
minute (which is the average in seven directions) ; although this is 
