TRANSACTIONS OF SECTION A. 919 
A comparison of the winds on the top of Ben Nevis with the surface winds 
shows that sometimes both are within the same cyclonic system or of the same 
anticyclonic system overspreading that part of Europe at the time. In such cases 
the direction is nearly always different, and so far as the investigation has been 
carried it appears that the observed differences give an indication as to whether the 
coming storm will pass to the north or to the south of Ben Nevis. " 
Sometimes, however, while the surface winds are part of a cyclone, the winds 
on Ben Nevis are part of an anticyclone, and vice versd; or putting it in other 
words, the manner of the distribution of atmospheric pressure at sea level over 
this region of North-Western Europe is quite different from what obtains over the 
same region at the height of 4,406 feet. It is this peculiarity in the winds and 
atmospheric pressure of Ben Nevis, due to its height and proximity to the central 
paths of the Atlantic storms, which will give to the observations an additional 
yalue in framing daily weather forecasts for the British Islands. 
12. On some Results of Observations with kitewire-suspended Anemometers 
up to 1,300 feet above ground, or 1,800 feet above sea-level, in 1883-85. 
By HE. Douactias ARCHIBALD. 
The author began by relating that he had, since the Montreal meeting of the 
Association, made twenty-five fresh observations, and as these embraced records 
at altitudes reaching to 1,300 feet above the ground, or 1,800 feet above the sea, 
he hoped the results from them, as well as fifteen of the former observations com- 
bined, might be considered sufficiently numerous and valuable to merit a short 
discussion. 
In the discussion the observations were divided into six groups, according to 
Sek: 
altitude, and the exponent for each observation in the formula es *) being 
v 
calculated, the means were taken for each group, with the following results: 
TABLE I. 
Mean height |Mean height eas AEN Re 
beep | upper _of ined ae Ae SS a Mean of | Mean value 
instrument | instrument | instrument | instrument both of x 
above ground|above ground ¥ 
H h V v 
q) 250 102 1,617 1,174 }, 1,395 372 
(2) 322 128 2,232 1,679 | 1,955 307 
(3) 407 179 1,705 1,385 1,545 “275 
(4) 549 252 2,107 1,773 1,940 237 
(5) 795 481 2,192 1,957 2,074 ‘250 
(6) 1,095 767 2,236 2,096 2,166 194 
From which it is manifest (as well as from the individual observations) that whale 
the velocity always increases with the height above the ground as far as 1,800 feet 
above sea-level, the ratio of the increase measured by the exponent x progressively 
diminishes. 
As the station itself is 500 feet above sea-level, the motion of the air at some 
height above the surface should correspond more or less with that at an equivalent 
height above the sea over an open sea-level plain. Where this actually is exactly 
the case is difficult to determine, but assuming that it is approximately the case at 
the mean level of group 6, or 931 feet above the ground, and adding 400 feet to 
both heights, we get 2 =0:26, which is nearly identical with the value already 
1 The exceptional case of group 5 being due to the inclusion in that group of an 
abnormally large value of 2 corresponding to an equally abnormally small velocity. 
