172 
J. HOPXINSON —METEOROLOGICAL OBSERVATIONS 
The mean temperature of the year was rather low ; the mean 
daily range was about the average. There were no high maxima, 
the extreme being 78°T in August, hut in December the low 
minimum of 12°7 was reached. The temperature was exceedingly 
variable, January being very mild, February very cold, the spring 
warm, summer cold, autumn warm, and December excessively cold, 
its mean temperature being 12°*5 lower than that of January, 
which is usually the colder month. The actual minimum in 
December, though low, is not exceptionally so, the cold being 
characterised by its persistence rather than by its severity.* The 
mean temperature from 26th November to 20th January, a period 
of eight weeks, was 29°*3, or 2°7 below freezing point, and during 
this long period the minimum sank below this point every night 
but three (5th and 6th Dec. 1890, and 14th Jan. 1891). The 
mean pressure of the atmosphere was a little above the average of 
the ten years 1877-86 at Watford. The lowest pressure recorded 
at 9 a.m. was 28712 ins. on 23rd January, and the highest was 
30717 ins. on 23rd February, giving a range of 2-005 ins. The 
rainfall was considerably below the average. July was very wet, 
477 ins. of rain falling; Feb., Sept., and Dec., were very dry, 
having an aggregate rainfall of only 2*04 ins. The air was rather 
humid and the sky rather cloudy. 
In the winter of 1889-90 (Dec. to Feb.) the mean pressure of 
the atmosphere was rather high, the mean temperature was about 
the average, and the rainfall was very small. In the spring (March 
to May) mean pressure was rather low, mean temperature rather 
high, and rainfall small. In the summer (June to Aug.) mean 
pressure was about the average, mean temperature very low, and 
rainfall heavy, with many wet days. In the autumn (Sept, to 
Nov.) mean pressure was rather high, mean temperature high, and 
rainfall very small. In each season the relative humidity was 
great, and while the sky was comparatively clear in the winter, it 
was unusually cloudy in the spring. The deviations from the 
means of our period are as follows 
Difference in 1888-89 from Means of 1877-86 at Watford. 
Seasons, 
1889 - 90 . 
Pressure. 
Temperature. 
Tension 
of 
Vapour. 
Humi¬ 
dity. 
Rainfall. 
Cloud, 
0-10. 
Mean. 
Daily 
Range. 
Total. 
Days. 
Winter . 
Spring . 
Summer..... 
Autumn. 
in. 
■+•141 
— ‘083 
—*009 
—1— * 121 
O 
+0*1 
+o ’5 
—i'7 
+i*2 
O 
-fo -9 
—0-4 
—1-4 
+17 
in. 
4-'ooi 
—-oio 
4-014 
% 
+ 2 
+ 3 
+ 4 
+ 3 
ins. 
—2-70 
— I*IO 
+0-90 
-4-07 
+ 3 
+ 13 
— 6 
—0-9 
+o-8 
+ 0*2 
+ 0’2 
* In an account of “The Great Frost of 1890 - 1891 ,” in ‘ Quart. Journ. R. 
Met. Soc.,’ vol. xvii, p. 93 , Mr. Charles Harding says that “so far as the southern 
portion of England is concerned, there does not seem during the last [i.e. present] 
century to have been any such prolonged period of frost as that of 1890 - 91 .” 
