172 
J. HOPKINSON-METEOROLOGICAL OBSERVATIONS 
In the previous report the means of some of the principal results 
of observations taken during the eight years 1878-85 are given. 
The following table shows the difference in 1886 from the means 
of these eight years, for each month, and for the year. 
Difference in 1886 from Means of 1878-85, at Watford. 
Months. 
Pressure. 
Temperature. 
Tension 
of 
Vapour. 
Humi¬ 
Rainfall. 
Cloud 
0-10. 
Mean. 
Daily 
Range. 
dity. 
Total. 
Days. 
in. 
O 
O 
in. 
% 
ins. 
January. 
— '420 
-1*1 
+0-9 
— 'Oil 
+ 1 
4 - 1-47 
4-io 
+o ’3 
February 
-J-'222 
— 7-2 
-2-3 
—-056 
—2*07 
— 9 
+ 1-3 
March . 
—•023 
—2*1 
—2-8 
4 " "OOI 
4-5 
4-0-36 
+ 4 
-fi ‘9 
April. 
— *046 
+i -3 
—0-2 
4--on 
4 -i 
4-°‘55 
+ 2 
4-o-8 
May . 
— •031 
+0-3 
— 
4--024 
+6 
4-2-28 
+ 6 
4 -o *3 
June . 
+ •042 
—o*6 
+i -4 
— •092 
—4 
-178 
— 7 
—0-9 
July . 
+ -OI 2 
+ 1-2 
+2 -0 
4--005 
— 1 
—0-46 
— 3 
—0*3 
August . 
-f -097 
+i ‘3 
+27 
4--oo8 
+ 2 
—174 
+ 1 
—0-3 
September 
+ •104 
-j- 2‘4 
4-1-2 
-j--oi6 
-0-93 
— 3 
4-o-i 
October. 
— -124 
+5 ’4 
— 0-2 
-f-o68 
+3 
4-0-48 
+ 5 
+ 0-5 
November 
—-008 
+ i *3 
4-1-i 
4 --oi 6 
4-3 
—0-19 
— 3 
4-17 
December 
-•279 
—0.1 
4-1-2 
—•015 
—2 
4-2-05 
+ 3 
—0*2 
Year . 
—•038 
+o-i 
4-0-4 
—'002 
+1 
—i*o8 
+ 6 
4-0-4 
The year 1886 commenced with very cold weather, February 
being an especially cold month; hut, towards the end of the year, 
up to December, the weather was warmer than usual, a cold period 
coming on again in December and lasting far into 1887. The mean 
pressure of the atmosphere was below the average; the lowest 
pressures recorded at 9 a.m. were 28-673 ins. on 16th Oct. and 
28-384 ins. on 9th Dec., and the highest were 30'745 ins. on 8th 
Feb. and 30*742 ins. on 24th Nov., giving a range of 2-361 ins.* 
The mean temperature for the whole year was about the average. 
The very low minimum of 13°-7 was recorded on the 8th of January, 
and minima below 20° occurred in February, March, and December. 
There were no very high maximum readings. The daily range of 
temperature was a little above the average. The rainfall was 
heavy, in May and December especially, hut very slight in Feb¬ 
ruary and August. It was, however, below the average of our 
eight-year period. The number of rainy days also was large. The 
relative humidity was about the average. 
Compared with the previous year, in 1886 the mean temperature 
was 0°-5 higher, the mean daily range the same, the relative 
humidity 2 per cent, greater, and the rainfall 0-11 in. less. Rain 
(or snow) fell on 4 days more in 1886 that in 1885, and snow 
(only) on 28 days more. The sky was more cloudy generally, 
* At 7*30 p.m. on 8th Dec. the mercury stood at 28-321 ins., increasing the 
range in the year to 2-424 ins. 
