The increase of mean temperature which results from skilful
enclosures, is estimated at 5° to 8° Fahrenheit; while in regard to
the increased money value, Mr. Thomas Bishop gives the following
testimony:--

"Previous to the division of the common moor of Methven in Perthshire,
in 1793, the venerable Lord Lynedoch and Lord Methven had each
secured their lower slopes of land adjoining the moor with belts of
plantation. The year following I entered Lord Methven's service, and
in 1798 planted about sixty acres of the higher moor ground, valued
at 2s. per acre, for shelter to eighty or ninety acres set apart for
cultivation, and let in three divisions to six individuals. The
progress made in improving the land was very slow for the first
fifteen years, but thereafter went on rapidly, being aided by the
_shelter derived from_ the growth of the plantations; and the
whole has now become fair land, bearing annually crops of oats,
barley, peas, potatoes, and turnips. In spring 1838, exactly forty
years from the time of putting down the plantation, I sold four
acres of larch and fir (average growth) standing therein, for L.220,
which, with the value of reserved trees and average amount per acre
of thinnings sold previously, gave a return of L.67 per acre."--Vol.
i, p. 367.


We are satisfied that in localities with which we are ourselves
acquainted, there are tens of thousand of acres which, by the simple
protection of sheltering plantations, would soon be made to exhibit
an equal improvement with either the moor of Methven, or the lands
upon Shotley Fell, which are also referred to in the work before us.
At a time when such strenuous endeavours are making to introduce and