Under -Dra imige. 
585 
other^vise have done, from the inequalities of the surface ; but with 
all this the result was a failui-e, and he was obliged to drain the whole 
over again. The depth of his di-ains was generally 4 feet, and there 
are many furrows where you can only see the head of a man in the 
next furrow. 
Mr. B. Denton, in reply to Mr. Dent's remarks respecting the state 
of Middlesex, stated that last week he went — not for the first time — • 
over a large estate in the neighbourhood of Harrow, belonging to Lord 
Northwick. He was accompanied by his Lordship, and the question 
which Mr. Dent had raised was discussed. They inquired of the 
occupiers why there was a disinclination to drain. The answer given 
was that it would lessen the quantity of gi-ass — the very thing which 
they most wished to avoid. They had a good customer, they said, in 
the London market, for any hay, let it be ever so bad, which they sent 
there, and therefore quantity was what they aimed at, and not quality 
(Hear, heai'). Now, he really thought that this was a comi^lete answer 
to Mr. Dent's question with respect to the drainage of Middlesex. He 
should add, however, that on Lord Northwick's estate there were two 
or three very intelligent tenants, who declared that the present system 
was a bad one, which they were altering, and intended to alter still 
further. For the futui'e the land would not be devoted to hay-growing 
only, but fed in part, and mowed in part ; that the moment the cattle's 
mouth reached the gToimd, di-ainiag was found to be very beneficial in 
the sweetening of the herbage ; but that di'aining did not increase the 
quantity of gi-ass, and therefore if they were dependent on the sale of 
hay, it would not answer their pm-pose. 
He was very anxious that his views with respect to the draining of 
porous land should not be misunderstood ; and he wished pai'ticularly 
to tell Mr. Dent that as regarded flat districts he did not anticipate 
that there would be a perennial supply of water, though it would not 
surprise him if that should be the case. But in those hilly, moun- 
tainous districts of the West and North, when the major portions were 
high, with valleys interposing, the low grounds were filled with the 
debris of the high lands, and were maintained in a constant state of 
saturation during summer by pressm-e ; in such cases under-diainings 
would create and maintain a constant flow. It should be borne in mind 
that every inch of rain falling on the sm-face gave 100 tons per acre ; 
and if the discharge of the under-drains was equal to 40 inches of water 
over the whole area under-drained — which is not at all imcommon in 
draining the low grounds of hilly districts — the quantity discharged 
would be 4000 tons per acre. 
Considering the quantity of water which under-draining removes 
from the reach of evaporation, and the quantity which must be con- 
stantly filtering through the soil from the higher to the lower level in 
hilly districts, it is clear that draining must frequently originate a 
supply, by affording a vent for the water of pressure. 
The Chairman said, living as he did on the banks of the Thames, 
he was in hopes that they would hear more about the influence of 
drainage on rivers. He well remembered the floods of 1809, and 
•other great inundations to the west of London. Li the neighbourhood 
