336 On the remarlcable Depression of the Thermometer 
to Wednesday, is scarcely less remarkable than the unusual 
cold which it succeeded, the mercury having risen in the course 
of 24 hours, nearly 40°, and indicated a transition fully as great 
as if we had passed, in that short interval, from the ordinary 
cold of winter to the extreme heat of summer. 
We have thus witnessed, within the short space of ten days, 
two remarkable meteorological phenomena: the greatest atmos- 
pherical pressure, and the most depressed temperature that have 
probably ever been observed, or at least that have ever been 
recorded, in this part of the island. The conditions of the at- 
mosphere which led to this unusual state of things, have, it may 
be concluded, produced a mutual re-action on each other ; the 
comparatively great cold which preceded the high state of the 
barometer, by condensing the aerial columns over this country, 
would cause a current of air to flow from all the contiguous 
regions to supply the deficiency in the equilibrium, and raise 
accordingly the barometer ; and, on the other hand, the subse- 
quent diminution in the pressure, amounting in a few days 
nearly to 2 inches, by allowing the air to expand itself, appears 
to have caused a powerful absorption of caloric, in consequence 
of the sudden dilatation, and thus added greatly to the inten- 
sity of the cold. 
The cold seems to have been fully more intense in this neigh- 
bourhood than in any other part of the kingdom. Indeed it 
does not appear, by the meteorological records in the Phil, 
Trans, for 150 years back, that it has ever been much exceeded 
in any part of Europe, excepting Russia and Sweden. In the 
severe winters of 1683, 1709, 1715, 1740, and 1768, the ther- 
mometer never descended below — 2° ; nor do we find a well au- 
thenticated instance of its being lower in Britain during any 
other year, than it stood here on tlie night of Monday the 17th 
instant, unless in 1780 % when it was observed by Dr Wilson, at 
Glasgow, 14° below zero, or 4° lower than it was seen at this 
place. 
P erhaps no circumstance is better fitted to illustrate the ex- 
treme severity of the late frost, than the fact of water freezing 
in our apartments, from 24 to 36 hours after the thaw began, 
and when the external air was nearly 10“ above the freezing 
* This remarkable cold happened on Friday the 14;th January, at 6 A. M. 
See Phil. Trans, 1780, p, 451.— En. 
