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XXVI. Farther Experiments on Cold , made at the Macfarlane 
Qbfervatory belonging to Glafgow College. In a Lettt from 
Patrick Wilfon, M. A. to the Rev . Mevil Mafkelyne, D. D . 
F. R. S. and AJlronomer Royal. 
Read May 24, 1781. 
DEAR SIR, 
Glafgow College, 
Feb 9, 1781. 
S OME days of very cold weather, which we had lately iti 
this country, having afforded an opportunity of profecuting 
a little farther the experiments and obfervations begun in the 
courfe of laft year, I now do myfelf the pleafure of communi- 
cating to you the following particulars, which perhaps may be 
considered as not unworthy of notice. 
The froft fet in on Sunday the 21ft of January, after a con- 
fiderable fall of i 'now on the preceding evening, and about mid- 
night the thermometers were expofed near to the Obfervatory 
in the lituations mentioned in my former letter. The follow- 
ing regifter fhews the difference of temperature between the 
fnow and the air, till eight o’clock on Monday morning, to 
which are fubjoined fome fads which prove very confomint to 
thole deferibed in the former paper. 
The figti - prefixed denotes degrees below o. The fign + 
degrees above o of Fahrenheit’s thermometer. 
Monday 
