Experiments on Cold . 389 
On Thurfday, January 25, the difference of temperature 
was found to be as here fet down. 
Thurfday morning. 
h. m. 
Thermometer 
in air. 
Thermometer 
in fnow. 
9 
45 
4 * 1 0 
- 
+ 3 
10 
- 
4 - 10 
** 
+ 3 
10 
3 ° 
+ 14 
.to 
4 * 4 
11 
- 
4 - 14 
;+ s 
1 1 
30 
+ 17 
- 
’+ 9 
12 
- 
+ 20 
, * 
+ 12 
12 
O 
CO 
+22 
m 
+ 20 
1 
afternoon. 
+ 2 5 
tea 
+26 
1 
30 
+27 
test 
+ 27 
From ten till eleven o’clock this forenoon the thermometer 
on the baluftrade in air, fix inches above the fnow, pointed to 
+ 14, and when tried upon the fnow to +10. About noon 
this day fome clouds were formed, which became quite general 
by one o’clock. 
During the two laft times of obferving, three experiments 
were made with a view of difeovering whether the fnow with- 
out doors was gaining any thing from the air ; or if any of it 
was carried off in the way of evaporation ? For this purpofe, 
a fliallow di£h, made of fheet brafs, four inches in diameter, 
was exactly filled with fnow, and carefully weighed. In order 
to defend the outfide of the difli from the air, that no hoar- 
froft might attach itfelf to the metal, a circular hole was cut 
in the lid of a pafte-board box, fo wide as juft to let in the difli 
Vol, LXXI. F f £ to 
