The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1840-05-05 00:00:00

THE LATE EARTHQUAKES IN SCOTLAND.

At a recent meeting of the royal *society of Edinburgh,
amongst other interesting papers read was one by David
Milne, Esq., on earthquakes felt in Scotland during the au-
tumn and winter of 1839. For the subjoined summary of
this document we are indebted to the Scottish Standard.
Mr. Milne stated that the shocks were first perceived on the
2d of October, and had continued, with hardly a week's in-
terference, down to the present date. The total number of
shocks, from that date down to the 13th of April, 1840, was
145. From the 3d October to the 2d November no day passed
without shocks, and on several days there were as many as 12
or 14. The shocks appeared to have diminished in number
and number as the winter advanced, though on the 7th of
April there was a shock only exceeded in severity by the great
one of the 23d October. The author then proceeded to de-
scribe the effects produced by this last mentioned shock, felt
at Comrie about 10h. 14m. p.m. It was perceived in all the
central and southern parts of Scotland, and extended to the
north, as far as Dingwall on the east coast, and Appin on the
west. This shock, as well as all the others, emanated from
we central point, situated about two miles N.W. of Comrie.
Kfter describing the effects of the most violent shocks, both
physical and moral, some of which were curious and inte-
resting, Mr. Milne proceeded to describe the undulation of
the earth's surface, which produced them. He showed that
the natural levels of the ground had been altered, and in some
case to the amount of more than two degrees, and in the opi-
nion of some intelligent eye-witnesses, four degrees. There
appeared to have probably two undulations, and cer-
tainly one consisting of an interior swell and a posterior hol-
low, which caused houses, situated on an hollow ground, to
to rock like boats on the swell of the sea. The velocity of
the undulation must have been intense, as it occurred through-
out the whule country, to which it reached at one and the
same instant. Houses situated on rock were not so sensibly
affected, and the shock was in all cases felt more in the upper
than in the lower flats. The shocks were transmitted to
greater distances in the direction of E.N.E. from Comrie
than in any other direction. Of all these phenomena, expla-
nations were offered. The author next noticed the probable
cause of the shocks, which he assigned to fractures or ruptures
in the earth's crust at a great depth. He considered that the
phenomena could be better explained on this assumption,
than by supposing, as many philosophers did, that the earth's
crust was floating on molten lava. The vibrations caused
by these subterranean ruptures, would rise vertically, as well
as obliquely upwards, and create at some places the sensation
of the shock coming from below, and at others, of its moving
forwards along the surface. The cause of these ruptures, and
their frequent occurrence near Comrie, was next adverted to ;
and some geological explanations were given, tending, as we
undersood, chiefly to demonstrate that the earth's crust is
there intersected by great lines of fracture, that these lines
were nearly parallel E.N.E. and that there had been frequent
outbursts of igneous rocks in them. It appeared that, for a
month before the commencement of the earthquakes, and for
some time after they were perceived, there had been in Perth-
shire an almost unprecedented quantity of rain ; notwith-
standing which, it was observed of the Erne, the Airdle, and
other streams near Stratherne, that they were not flooded as
might have been expected. The fact of these earthquakes
being in some way connected with the rain, was rendered
probable by the fact, that in former years, they had been
almost always preceded by rainy weather ; and it was known
that if water percolated to the depth of one mile and a half into
the earth's crust, it would, in consequence of the subterrane-
an heat, generate steam, which might cause ruptures. The
water might, in Perthshire, percolate into subterranean
depths, by the numerous fissures abounding in it. It was
further shown, that for a month before the commencement of
the earthquakes, the atmospherical pressure was less than it
had been for several years ; whereby any volcanic forces be-
neath would be enabled to press or push towards the earth's
crust with unusual effect, and thus facilitate the percolation
of water to its fissures. A number of other phenomena was
mentioned, such as a peculiar smell or odour, and a black
powder which fell extensively in the district, and floated on
Loch Erne, last October; but in consequence of the lateness
of the hour, they were not fully described.