372 Mr D. Milne on Earthquake Shocks felt in Great Britain, 
tober last, occurred forty years ago. The sky had then the 
same appearance as it had on the late occasions, and the sound 
was as loud, but there was only one concussion, and no heave 
of the ground. It rained continually that day and the day 
before ; and at the time of the shock, the rain poured. The 
rivers have been larger this year than for forty years before ; 
and springs have been very copious ever since, and before they 
were diminished for a short time by the shock.” 
| (2.) Dr Gairdner, M.D., writes :—“ I was sitting in a room 
on the ground floor reading, when suddenly there was felt and 
heard as if a large body was propelled with great force on the 
ground forming the north-west foundation of the house, from 
which it seemed to rebound on a part of the ground nearer 
the house, causing a violent shake or tremor. The feeling 
was exactly as if the house had been driven an inch or two to 
the east, by some very powerful shock upon its westerly foun- 
dation. Immediately the shock occurred, I threw myself back 
in my chair, and planted my feet forwards ; I was sitting with 
my face to the west. Andthe question occurred to me, Was 
this an instinctive movement to preserve the equilibrium, dis- 
turbed by a change in the horizontality of the ground? If 
so, from the nature of the position taken, the ground must 
have been upheaved before, and was at that moment (when 
the shock was being felt) returning to its former level. Being 
intently leaning over a book at the time, I could not pay much 
attention ; but it was always impressed on my mind, that there 
was something strange immediately preceding the shock. 
However, although there were a number of articles in the 
room that would have been sensibly affected by this or any 
undulatory motion, I could perceive no sign of it in any of 
them. They, of course, partook of the tremor or vibration 
which was general at the time. The shock, although double, 
was momentary, hardly a second intervening ; and the accom- 
panying shock did not last above a couple of seconds, but the 
duration of the vibration would vary with the body operated 
on. The rumbling noise which succeeded the shock appeared 
to last about 15”. It resembled what we might suppose the 
noise produced by a number of carriages running over the 
macadamised road of a wide tunnel stretching to the south- 
