348 Dr. percival’s Account of a 
furface for the a£tion of the fun and wind^. Thefe 
might be covered in rainy weather with awnings of can- 
vas, painted on the outfide black* and white on the in- 
lide ; the former with a view to abforb, the latter to 
reflect, the rays of light. 
( a ) The following abridged view of a meteorological regifter, which I kept 
with great exa&nefs during the years 1774 and 1775, may throw fome light on 
the practicability of this plan in the climate of Lancafhire, which, I believe, 
is nearly the fame as that of moft of the other Wetlern counties of England, 
1774 
Thermometer 
Days 
2 o’clock. 
P.M. 
t 
Rainy 
Fair. 
Jan Feb. March, 
56 
0 
28 
25 
65 
April, May, June, 
72 
45 
55 
3 6 
July, Auguft, Sept. 
75 
53 
66 
26 
Oft. Nov. Dec. 
60 
3° 
43 
49 
1775 
Jan. Feb. March, 
54 
3° 
61 
29 
April, May, June, 
00 
5i 
42 
49 
July, Auguft, Sept. 
74 
48 
62 
3° 
Oft. Nov. Dec. 
64 
32 
5°* 
28* 
* Fourteen days omitted, no account being taken. 
The thermometer, ufed in making the preceding obfervations, was graduated 
according to the fcale of Fahrenheit. It was placed in the open air, and in 
a Northern expofure. The column of rainy days expreffes the leaft as well as 
the greateft quantity of rain. The column of fair days includes only thofe 
days in which not a tingle fhower was noticed. The day comprehends twenty- 
four hours. 
The mean quantity of rain which annually falls here is about 33 inches. 
This 
