134 
J. HOPKINSON—CLIMATE OF HERTFORDSHIRE. 
The direction and force of the wind remain for consideration. 
With regard to direction, the following are the mean results of 
observations at Berkhamsted, St. Albans, and Bennington for the 
twelve years:—N. 36T days in the year, N.E. 36*4, E. 294, 
S.E. 25*8, S. 39-3, S.W. 61*5, W. 61*4, N.W. 32-2, and calm 43*2, 
making together 365*3 days, the inclusion of three leap years 
adding a little to the mean number of days. Referred to the four 
cardinal points of the compass and neglecting fractions of days the 
result is: N. 70 days, E. 61, S. 83, W. 108; and referred to the 
intermediate points: 3ST.E. 69 days, S.E. 61, S.W. 112, N.W. 80; 
to which must he added in either case 43 calm days. This shows 
how greatly south-westerly winds predominate. 
Eor the direction of the wind in each month I have only worked 
out my own observations at St. Albans, and according to them in 
the twelve years January had the greatest number of calm days 
(3*6), April of days with N.E. (6*2) and E. (3*2) winds, May of 
N. (5*4) and N.W. (4*6), August of S.W. (8*4) and W. (5*7), 
November of S.E. (3*3), and December of S. (5*5). Eebruary had 
the least number of days of S.W. winds (3*4), March of S.E. (1*8) 
and calm (1*1), April of S. (2*3), May of W. (2*8), August of N.E. 
(1*9), October of E. (0*9), November of N.W. (2*3), and December 
of N. (1*9). The largest number of days in any month with the 
wind in any one direction is 8*4 of S.W. winds in August; it is 
most nearly approached in July, which has on the average 6*6 days 
of S.W. winds; and the next largest number is 6 2 days of N.E. 
winds in April and the same number of S.W. winds in November. 
With regard to the force of the wind there are anemometers at 
Berkhamsted and Bennington, hut their records have not been 
published, and I have only the results of my own observations of 
the estimated force at St. Albans to rely upon. In the absence of 
an anemometer the wind-force is estimated on the Beaufort scale, 
0 representing calm and 12 a hurricane. As the extreme force is 
(fortunately) never experienced in this country, it is difficult to 
say how nearly it is approached in a severe gale, and it is not 
always easy to say whether the air should he considered as calm 
or as having the force 1. I have entered it as calm when my vane 
(which moves with a very gentle breeze) was quite still, and as 
having the force 1 when it oscillated very slightly, and so on. 
The greatest force at which I have estimated the wind at 9 a.m. 
on any occasion is 6; a force which has been recorded more than 
once in some years and not at all in others. The greatest estimated 
mean force in any month was 2*8 (March, 1891); the least in any 
month was 1*2 (January, 1887; November, 1892; September, 
1893 ; October, 1897 ; and September, 1898). The mean annual 
force is 1*8, and it has varied in different years from 1*6 to 1*9. 
The wind is strongest in Spring (2*0), lightest in Summer and 
Autumn (1*7), and the mean of the year in Winter. It is strongest 
in March (2*1), and lightest in June (1*6). 
