extraordinary Degree cf Cold at Glafgow. 459 
cold. During the whole time not a cloud was perceiva- 
ble, but there was a faint haze in the air when viewed 
towards the horizon. There was little or no tremor iix 
the atmofphere, which made the ftars to ihine with a 
full and Heady light like that of the planets. Many of 
the citizens, who had thermometers hung out at their 
windows in different places of the town, found them 
pointing feveral degrees below o at nine o’clock in the 
morning. On the afternoon of this day, being Friday, 
Jan. 14th, the air became much warmer, and the baro- 
meter had now fallen four-tenths. Next day a thaw 
came on, and continued for fome time. 
As the above experiment with the bellows favoured 
fo little the opinion, that the difference of temperature 
was caufed by evaporation, I began to think, that it 
might be owing to a continued defcent of cold air fome- 
where in the neighbourhood, which cooled the fnow by 
fweeping along its furface in fo thin a fheet as not to 
affedt the air a little higher up. But as this folution of 
the phenomenon was fo arbitrary, and unfupported by 
any fadts, I wifhed for another opportunity of making 
further experiments, and of enquiring into circum- 
ftances Hill more attentively. A good occafion offered 
on Saturday, Jan. 22. The frail, which before this time 
had again returned, became on this night very keen; 
Vol. LXX. P p p and 
