4-22 
Farming of Cornicall. 
They are made of stone, having gutters, and filled above with 
small stones from 2 to 4 feet high.* 
34. Draining is frequently required on our slate-hills, in conse- 
quence of the outbursting of springs, which break forth with great 
freedom in the winter months. The principle on which their 
drainage is effected is first to find the origin of the spring ; and 
one single drain sunk into the water-bearing stratum, varjang 
from 4 to 8 feet in depth, will lay a great extent of land dry. 
Should it happen that the water has soaked and become diffused 
throusrh the soil, branches or small drains are necessarv, which 
are so constructed as to fall into the main drain. These varv in 
depth from 18 inches to 2^ feet, and are generally filled with 
small stones, without gutters, although in some cases these become 
requisite. We have very little tile-draining in Cornwall; stones 
are easilv and cheaplv obtained, except on the " carbonaceous 
soils"! (21). 
35. Improvement of the Soils hy subsoil plouf/hiiif/. — This is an 
operation that has occasioned some little agitation of late. It has 
been practised in a variety of instances on different kinds of soils ; 
on some with great success, and in others it has completely failed. 
Its advocates strongly recommend its adoption as a means of 
increasing the depth of all our soils ; whilst its opponents main- 
tain, that to augment a shallow soil by bringing to the surface an 
inferior subsoil, renders what was previously of some little value 
comparatively worthless. I believe that both parlies are fre- 
quently wrong in their conclusions. This operation should never 
be resorted to unless the land has been either drained, or was com- 
pletely dry ; and in instances where the subsoil consists chiefly 
of siliceous and aluminous matters, it certainly is not likely to 
benefit a thin meagre soil. \S hen potash and lime are present in 
the subsoils i (61 J, it will certainly prove advantageous. Sub- 
* Some of these levels require drains to the depth of 15 feet. The 
operator stands in the drain, cutting out before liira, making the drain, 
and filling up behind him. 
••• Lady Basset has successfully thorough drained by the use of tiles 
about 60 acres on this formation at Whitstone farm, near Stratton. ^The 
whole of this kind of soil is beset with springs lising to the surface from 
clayey beds beneath. From the diflBculty of obtaining it ones, bush drain- 
ing' had been extensively practised previous to the introduction of " tiles," 
the latter being more efficient and durable. 
X The ' Cornwall Agricultural Association " in 1842 offered a premium 
for the best ' Report of Experiments on Subsoil Ploughing.' Detached 
information on this subject having been published from time to time as 
the result of experiments in other counties, on soils different from our 
own, it was considered advisable that experiments should be made on the 
different geological strata in our own county. This produced a paper 
containing a series of experiments by Mr. Peters of Tehidy, on this sub- 
ject, in 1843, which being unpublished, I insert by permission the three 
following experiments : — 
Exjuriment 1. On Slo/e ^'oi7«-.— In a field of 3 acres lying upon a slope 
