190 
J. HOPKINSON-METEOROLOGICAL OBSERVATIONS 
The monthly means and other results of the daily observations 
in 1887 are given in the accompanying tables (pp. 188, 189); and 
from these tables the following summary for the seasons is deduced. 
Tor the winter of 1886-87 it has been necessary to take the values 
for December from the observations at Watford as given in the 
previous report. 
Means eor the Seasons from Dec. 1886 to Nov. 1887. 
Seasons, 
1886-87. 
Temperature. 
Tension 
Humi¬ 
dity. 
Rainfall. 
Cloud, 
0 - 10 . 
Pressure. 
Mean. 
Daily- 
Range. 
of 
Vapour. 
Total. 
Days. 
Winter . 
ins. 
30 -028 
O 
36-0 
O 
ii *6 
in. 
•186 
7o 
89 
ins. 
7*02 
43 
7-1 
Spring . 
30-048 
43'4 
15-3 
•229 
82 
5-04 
46 
7-0 
Summer. 
30-096 
62-3 
21 -i 
•375 
66 
2’6o 
22 
4‘9 
Autumn. 
29-918 
45'9 
12-3 
•262 
85 
8-14 
5 i 
6 - 6 
Having extended the computation of the observations taken at 
Watford from the means of the eight years 1878-85 as given in my 
report for the year 1885, to those of the ten years 1877-86, I now 
give the difference in each month and in the year between the 
chief results for 1887 at St. Albans and the means for these ten 
years at Watford. 
Difference in 1887 from Means of 1877-86 at Watford. 
Temperature. 
Tension 
Rainfall. 
Cloud, 
0 - 10 . 
Months. 
Pressure. 
Mean. 
Daily 
Range. 
of 
Vapour. 
Humi¬ 
dity. 
Total. 
Days. 
January. 
in. 
— -on 
O 
— 2-4 
O 
+ 1 ** 
in. 
—-019 
% 
— 1 
ins. 
— 0-71 
— 1 
-f-o - 4 
February 
+ •399 
— 2-0 
+ 2-8 
—’017 
+ 1 
—i’95 
— 9 
— 1-4 
March . 
+ •111 
—3 -2 
— I 2 
— -017 
+ 5 
+ 0-04 
= 
+i-i 
April. 
+•145 
— 3 -2 
+2-3 
— *025 
+ 4 
— 1*16 
— 3 
—o*9 
May . 
+ •070 
— 2*6 
—3*o 
—•015 
+ 7 
— 0-29 
+ 7 
+i -6 
June . 
+•243 
+i'9 
+3*3 
—•003 
— 4 
— 2*21 
—10 
—o -6 
July . 
+ -II2 
+4‘i 
+4*6 
—-006 
—11 
- 1-65 
— 4 
- 0-9 
August . 
+'080 
+o-3 
+3*8 
— •058 
—10 
— 1 *55 
— 7 
— 2-4 
September 
— -029 
—27 
—2 -2 
—•056 
— 4 
+ 0-51 
+ 5 
—o -6 
October. 
+•174 
-37 
-0-7 
— -050 
— 3 
—i'44 
— 4 
+o-5 
November 
— -202 
-27 
— r ‘9 
— •016 
+ 3 
+078 
+ 2 
-fo -6 
December 
— -113 
— o‘6 
+07 
— "Oil 
— 1-09 
+ 2 
-j-0-2 
Year . 
+•082 
— 1-4 
-fo -8 
—•025 
— 1 
— II*I2 
— 22 
—0‘2 
The cold weather which commenced in December, 1886, lasted 
without intermission until the summer of 1887. July was particu¬ 
larly warm, August was about the average, hut in September 
another cold period set in and prevailed almost continuously until 
near the end of 1888. The mean pressure of the atmosphere was 
rather high ; the lowest pressures recorded at 9 a.m. were 28 888 ins. 
