61 
percentage, 30, as the sunny days were less concentrated upon 
the summer months. So, too, the 1370 hours of 1882 gave 31 
percent. At the other extreme is 1885, with only 22 per cent, 
from 980 hours. Yet that year was warmer (0 2“) than 1887. 
In the warmest year, 1884 (49* 1°), the sunshine hours were 
1243, or 28 per cent. May was the sunniest month (187 hours, 
and 37'8 percent.), whilst December, naturally, comes last with 
24| hours and lO^ per cent.; but January can only boast 25-6 
hours and 10'6 per cent. For the first five years these last 
values were 222'7, 45 per cent. ; ]7‘8, 8 per cent. This great 
divergence shows that a more extended series of observations 
may, of course, materially modify their values. Indeed, next 
to rainfall, nothing has proved so irregular as the amount of 
sunshine. The annual variation is 40 per cent ; hence we may 
guess that the true mean lies between 25 and 29 per cent.. In 
December it has ranged from one hour to 70, or 0 per cent, to 
31 ; in May, from 97 to 273 hours, or 20 to 55 per cent. This 
last was in 1882. Other records of over 200 hours in the month 
are, Ala}^ ’81, 272 hours; ’^3, 2(U ; ’81, 210; ’88, 222; June 
’87, 205 hours; ’89, 238; July ’87, 209. It is striking to 
notice how much July falls behind May, although its opportu¬ 
nities are slightly greater. The order, according to percen tage 
of sunshine runs, indeed, as follows :— 
Probable ap¬ 
proximation to 
mean. 
The sunniest 
months. 
Older by 
percentage. 
[ ^loritll 
May. 
June. 
Aug. 
July. 
Aprl. 
Sept. 
Mar. 
Oct. 
Feb. ' Nov. 
Jan. 
Dec. 
1 Percentage 
37-8 
33-5 
32-5 
32T 
30-6 
28-1 
2.5-9 
25-1 
19-5 16-9 
! 
10 6 
10-5 
Hours.... 
187 
169 
148 
162 
128 
lOd 
99 
81 
53 ! 42 
26 
25 
After the first four, the present order, it will be observed, is 
very natural. Spring and Autumn months pairing off regularly. 
Cleau Days. There is not, unfortunately, any settled clear Days, 
1 2 J-* i-1 1 i? i-1 * 1 i-1 1 * estimated bvvis- 
system lor estimating the clearness ot the air along the horizon ; ibiiity of West 
but, since November, 1882 , I have been accustomed to record 5 n?e"Nov ,?8S2! 
all days when the West Riding hills were seen by me, due 
West, from my house on Bootham Stray. 
The record is imperfect from freepient absence during parts 
of the day, and also during parts of January, June, December, 
and all July Each year, however, was subject to almost tfie 
same conditions. The sjtiirs are distant 25 to 30 miles, the first 
Record uoi 
complete 
