Some Statistics of Thunder and Lightning at Kirtiberley. 
109 
Von Bezold and others have found that high temperatures produce years 
with abundant thunderstorms. The idea is not new ; and it is in fact stated 
almost in so many words in the Anglo-Saxon Manual of Astronomy : — 
Swa hattra sumor swa mara ^unor ^ liget on geare." For that matter 
neither is it generally true. At any rate it is not true for Kimberley, where 
much rain, and therefore many thunderstorms, signify cooler weather. The 
following table gives the hourly mean temperatures of January arranged in 
order of magnitude, together with the total duration of thunderstorms, and 
of lightning without thunder, for the 20 years 1900 to 1919. 
January 
Mean Temperatures 
Thunderstorms 
Lightning 
(Fahr.). 
(hours). 
(hours). 
/y o 
1 t;.A 
10 U 
zy u 
1 Q1 K 
lyio 
17Q.Q0 
/o 0 
iy z 
4/ 0 
20"5 
0^.0 
Z/ Z 
1919 . 
77-6° 
17-2 
26-0 
1913 . 
77-3° 
35-5 
37-0 
1906 . 
76-7° 
7-2 
15-0 
1903 . 
76-6° 
21-5 
28-0 
1917 . 
76-4° 
29-5 
10-5 
1916 . 
76-3° 
37-7 
37-0 
1911 . 
76-0° 
4-5 
20-5 
1901 . 
75-7° 
20-7 
33-2 
1905 . 
75-6° 
46-5 
29-2 
1910 . 
75-2° 
21-2 
39-5 
1900 . 
74-6° 
16-2 
12-2 
1909 . 
74-6° 
180 
22-5 
1908 . 
74-2° 
28-2 
180 
1907 . 
73-5° 
33-0 
52-7 
1918 . 
73-2° 
18-7 
36-0 
1902 . 
72-9° 
21-0 
23-2 
1904 . 
72-8° 
13-2 
23-7 
From which we deduce for January mean temperatures above 75*9° : 
Mean Thunderstorm duration . . . 20*8 hours. 
„ Lightning „ ... 27-8 „ 
„ Total 
And for mean temperatures below 75 '9° 
Mean Thunderstorm duration 
„ Lightning „ 
„ Total . . . 527 „ 
The present essay was not intended to be more than statistical, compiled 
as a contribution to the meteorology of the Table-land of South Africa, and 
48-6 „ 
23-7 hours 
29-0 „ 
