extraordinary Degree of Cold at Glafgow. 463 
feveral detached bodies which had attra&ed a very thick 
hoar-froft. When the thermometer was taken off the 
hook of the pole, and laid on this hoar-froft, there was 
always a remarkable fall of the mercury, not lefs than 
6®. Both Dr. crawford and I were much ftruck with 
this fadt, and attended to it very carefully. 
In tranflating the inftrument from the pole to the 
balluftrade, it was commonly laid on fome hoar-froft 
three quarters of an inch deep, which had fettled on a 
piece of thin board which had been for years expofed to 
the weather. Some fragments of the hoar-froft were 
alfo made to touch the upper part of the ball; which was 
done by pufhing them on with a long frozen ftraw. 
EXPERIMENT VIII. 
When the thermometer taken from the pole as in 
laft experiment was laid on pieces of ftone, from which 
the hoar-froft had been brufhed away for fome time be- 
fore, the mercury funk but very little by fuch a change 
of fttuation. 
Next night, being that of Sunday Jan. 23. the ther- 
mometers were placed in their former ftation below, 
when at 
9 o’clock 
