0)1 the Climate and A(jricuUurc of the British Isles. G5 
on the contmi'v, ;i. 1000 foot of !ieii;ht at one station ^avo only 
58 inches ol' rain, and 1140 feet at another station 114 inches. 
Consichning- that the whole range of the mountains from 
North to Soutli Wales is exposed to the full effects of the 
westerly winds, the amount of water deposited on its oOOO 
S(ptare miles of elevated hills must be very great, and the water- 
power, if ever made available, is enormous. 
These hills act as a breakwater to the aerial floods from the 
sea, and so drain the rain clouds of their contents, that in the 
broad rich valley of the Severn, and northward to the plain of 
Cheshire, only about 25 inches of rain falls annually. The rich 
pasture lands of the lias clay of Worcester lie low : a mountain 
rainfall would convert them into a worthless puddle. 
The Cumberland mountains olfer perhaps the best example 
of excessive rainfall, from 40 inches at Whitehaven on the 
coast, to 224 inches at the Stye, 1077 feet high. In this district 
a still greater disproportion is shown between the height of the 
station and the amount of rain, as in the following instances : — • 
Height of station (ft.) 3G 247 422 C95 1077 1985 2550 3300 
Rainfall (in.) .. .. 40 102 197 90 224 139 91 68 
The gauges have in this district especially shown the enormous 
ratio of increase of rain at the head of the valleys. In the 
same valley, near Buttermere, three gauges were placed only 
two miles between each, and the increase of the yearly amount 
of rain up the valley was respectively 76, 98, and 133 inches. 
On the western coast of Scotland there are two important 
stations, on points of land running far out into the Atlantic, 
and beyond any influence from the Scotch hills, Barrahead and 
the Rhinns of Islay ; here the rainfall, which must very nearly 
represent that on the open ocean, is about 31 inches, agreeing 
with that before mentioned at the Scilly Isles and the Land's 
End. But on the western Highlands the rainfall is tropical in 
its amount, and the quantity is greatly increased at the heads of 
the lochs and valleys ; thus at the head of Loch Katrine the 
annual amount is 87 inches, and at Ben Lomond, 92 inches. 
And the stations along the western coast, appear to indicate 
that the whole range of the western mountains have an excessive 
amount of rain. There is, however, a more instructive example 
of a large annual rainfall in the Isle of Skye. 
The ancient sedimentary rocks of the Highlands strike south- 
west, and many of the principal lochs and glens run in that 
direction, and thus the parallel ranges of hills present their ends 
to the south-west wind which sweeps along their sides ; but 
Skye is almost wholly composed of Trappean rocks, and the 
crests of the hills, rising to 3000 feet, range north-west and 
VOL. IV. — s. s. r 
