255 
On the hills near Glenfinlas, which form the eastern summit of' 
the land draining to Loch Katrine,, and further to the east, at 
an elevation of 1,800 feet, the rain was reduced to 62 inches. 
In 1857, the rain on the first ridge was 84 J inches, on the 
second 74^- inches, and on the third 48^ inches. In 1859, 
two years subsequently, it was 92 inches, 854 inches, and 
48 inches respectively, and so for every year. 
This shows the importance of bearing in mind that it does 
not do simply to calculate on increased elevation giving an 
increased quantity of rain, but the whole question is affected 
by the geographical disposition of mountains and valleys. 
The heads of all valleys, too, in mountainous districts, give 
larger quantities of rain than the mouths of valleys. Thus 
at Loch Yenechar, at the mouth of the great valley in which 
this Loch and Loch Katrine lie, the rain in 1872 was 78 in. 
at an elevation of 275 feet above the sea, while at Glengyle, 
380 feet only above the sea, at the head of Loch Katrine, the 
rain was 127 T & ^- inches, and in the same year, on the flanks 
of Ben Lomond, 1,800 feet above the sea, it was 96-| inches. 
In the year 1866, the rain at Loch Venachar was 64 inches. 
At the head of Loch Katrine 101 inches, and on Ben Lomond 
100 inches. 
From these observations it will be seen that the rain varies 
very much in the same district irrespective of elevation, the 
variations depending upon the physical and geographical 
features of the country. 
Much of the rain which falls, however, is lost by absorption, 
evaporation, and other causes. Part of it runs away in floods ; , 
some enters the bowels of the earth, to be reproduced in 
springs; and some supplies the wants of vegetation. The 
result greatly depends upon the quantity of rain which falls, 
and upon the greater or less declivity of the ground on which 
it falls, as well as upon the character of the vegetation. 
Where the hill-sides are steep and the rain is considerable, the 
loss is least; where the declivities are gentle, the growth 
of herbage heavy, and the quantity of rainfall small, the 
loss is greatest. It varies, according to these qualifying 
circumstances, from about 8 inches to 20 inches per annum. 
It therefore follows that in regions of small rainfall nearly the 
whole is evaporated, leaving barely sufficient for purposes of 
vegetation. Where the rainfall is great, much of that which 
falls runs away in floods ; but all water, no matter how found, 
is the produce of the rain which falls upon the surface, and 
we are therefore happy in this country in being so surrounded 
by water that we have always an abundant rainfall for all 
purposes of life and enjoyment. 
