OF FREQUET^Cr OF THE BAROMETRIC HEIGHT AT DIVERS STATIONS. 
457 
Babbacombe 
Cbnrcbstoke 
Southampton 
Laudale . 
Hillington . 
Churchstoke 
j 
30"-2745 
28"-5022 
31"-0477 
t 
1 
The following are the balance heights of the three pairs of stations dealt with in 
Table XL :— 
Above this value Churchstoke, below Babbacombe, 
has usually the higher barometer. 
Above this value Southampton, below Laudale, 
has most probably the higher barometer. 
Above this value Churchstoke, below Hillington, 
has most probably the higher barometer. 
In the case of close and highly correlated stations, the balance value, since the 
probable deviation is small, may be roughly found from a mere inspection of the 
barometer records for the two stations. Thus, we expect, it is about 30''‘5 for London 
and Cambridge. Perhaps a better approximation might be obtained by estimating, 
I 
v. 
--- 
-- 
“ — I 
’'■'Vi 
— 
1' 
1 
1 
1 
\ 
V- 
1 
1 
T 
t 
-^T 
r 
"(s' 
> 
— 
> 
'Gi 
— 
4 
1 
1 
4 
1 
d' 
'O' 
1 
1 
1 
1 
1 
1 
1 
oM/es 
/oo 
/£0 
^oo 
500 
D/sC&nces SeCween 
Diagratn illustratirig apjolication of Theory of Correlation to predict Barometric Heights. 
Stations approximately orthogonal to isobars. 
. Stations approximately adong isobars. 
from their known distance, the coefficient of correlation for the two stations by 
means of the diagram above, and then calculating since cr^ and o-o are given in 
Table lA^., or can be found by interpolation from that table. 
The diagram indicates graphically, what is faiidy clear from Table XL, that correla¬ 
tion is not a single valued function of the distance between the two stations, It 
YOL. CKC.— A, 3 N 
