on certain strong Clay Subsoils. 
243 
Swanton, near Folkingham, February 17, 1847. 
Sir, — I will answer your postscript first. My opinion is decidedly 
against deep drainino^ on strono^ clay land. The parish where I reside is 
composed of part field and part I'en ; a great portion of the field land is 
strong clay. Several years ago when we first commenced draining with 
tiles, they were put in deep, 3 feet 6 inches, and the lands being wide 
with high ridges were thrown down so as to make the surface level : after a 
short time the land became so solid, that surface water could not get 
down to the drains, and it remained on the land in a stagnant state, to the 
manifest injury of the growing crop, and the land had to be top-gripped 
in the same manner as if it had not been underdrained, or nearly so. We 
have now altered our plan, and now rarely drain deeper than 18 to 24 
inches ; the tiles we invariably cover with a small portion of stubble, and 
then with the soil dug out, but never ram the earth on the drains. There 
is an inclination to drain deep m porom soils, where the fall will allow it. 
Yours, &c. W. Moore. 
W. B. Webster, Esq., Sec. &c. 
In Yorkshire the greater portion of the soil being the new 
red sandstone is naturally rather porous, and of a character 
fitted for deep drainage ; and on the coal measures near Rother- 
ham there is in places found much underwater, which, as it 
generally comes from a higher level, and constantly forcing its 
way to the surface, requires to be removed, or seriously damages 
the crops. Very different, however, are the coal formations of 
Durham and Northumberland. I remember going for eight 
miles underground (in a coal-pit), in the neighbourhood of New- 
castle-on-Tyne, where the soil above was of a strong nature, such 
as to require draining at about 30 inches deep, yet where but 
little of the surface water percolated to the mine ; yet the perco- 
lation of water is often a source of the greatest annoyance in 
mines of great depth, where the superposed strata consist of 
mild clays and porous rocks. The following is a letter of the 
well-known Mr. Stephenson, of Throckley, near Newcastle-on- 
Tyne : — 
Tlirockley House, March 1, 1847. 
Dear Sir, — I received your letter. Not having sufficient experience, 
I cannot answer it respecting 40 feet apart. I should doubt the result 
being satisfactory. In 1845 I drained a field 30 acres, 10 yards apart and 
3 feet deep, strong clay, which has given me every satisfaction. I had a 
splendid crop of wheat upon it last year, and the whole field appears per- 
fectly dry and fit for every purpose. 
I have drained 60 acres since October 20 feet apart, 30 inches deep, and 
am perfectly satisfied it is the best distance and also depth for strong clays. 
The effects are astonishing. Yours, &c. W. Stephenson. 
W. B. Webster, Esq., &c. &c. 
From such opportunities as I have had of examining the soils 
of Scotland, I have found reason to believe in that part of the 
island the clays are generally of a less retentive nature than what 
are common in the south ; and evidence of this is seen in the fact 
that the tread of the horses in ploughing double is not, as on 
many of our English clays, injurious to the land. This milder 
R 2 
