and the Weather which preceded and followed. 541 
yet, as in the former instance, the cold was not equally severe 
the whole time. For the first nine days, that is to say, from 
the 8th to the 16th of January (both days inclusive), the mean 
temperature of the 24 hours ranged from 28° to 33°5°; but 
on the 17th it descended to 25°, and on the 18th to 16°.* 
On the 19th it was likewise as low as 20°5°, but on the 
20th it rose again to 32°; and thence to the 30th the cold 
somewhat abated, the mean temperature seldom descending 
much below the freezing point, and occasionally rising as high 
as 34° and 35°. However, on the 31st, the frost again set in 
with increased severity ; and the mean temperature of the six 
first days in February was only 20°6°. 
I have endeavoured above to trace the principal fluctuations 
of the mean daily temperature during the continuance of this 
long frost. The first break to the severe weather occurred on 
the 7th of February, when a decided thaw took place, attended 
by much wind and driving rain from the south; yet, after two 
or three days, the weather showed a strong disposition to 
relapse into its former state, and a full fortnight expired 
before there was any considerable rise of the thermometer ; 
which instrument, during this period, was seldom higher 
than 40°, often not so high, and frequently descended in the 
night to 28° and 25°. It was not till the 24th of February 
that any thing like an approach to spring weather was expe- 
rienced. On that day, however, without any apparent cause, 
the wind remaining in the same quarter in which it had been 
for the four previous days, the thermometer rose to 55°5° in 
the shade, being more than 10° higher than it had stood at 
any time before since the commencement of the new year. 
This sudden increase of temperature seemed to exert consi- 
derable influence over both the animal and vegetable world : 
a few plants were observed in flower; many insects came on 
wing; the birds resumed their song; and, more especially, 
large flocks of wild geese, none of which had been noticed 
since October, 1829, were seen shifting their quarters princi- 
pally in the direction of north and north-west. Neither was 
this a mere temporary change: from that time the weather 
became more seasonable, and, especially from the little rain 
* It is a curious fact, that during this severe weather a brood of tipuli- 
deous insects (Trichdécera hiemalis MJeig.) suddenly made their appearance 
and were noticed abroad in considerable numbers, settling upon the walls 
of different outbuildings, as if they had just emerged from the pupa state ; 
and though they did not offer to take wing for several weeks, yet they 
readily moved their quarters when disturbed ; a proof that, notwithstanding 
the continued frost, they had the power of resisting torpidity, and to a 
degree far exceeding any other insects. 
NN 3 
