252 
On Draining. 
before us, well ascertained by various careful observers and prac- 
titioners, that lands which have been drained to a certain depth 
without effecting a cure of wetness, have entirely lost their drop- 
sical habit when under-drained to a je;reater depth. The evidence 
to niy mind is irresistible that a less depth of drain than four feet 
in any soil will not be accompanied by those beneficial results 
which we obtain at that, and in some soils by a still greater depth 
and if time permitted I should not doubt the bringing before you 
a mass of evidence, drawn from my own practical experience, as 
unimpeachable as it would be convincing, that drains executed to 
these depths are not only the most efficient, but the most econo- 
mical, when the conduit is formed of cylindrical pipes. 
Before, however, entering on the detail of one or two interesting 
and peculiar examples of the effect of deep drains, I am desirous 
of making known to the Society the opinions of an excellent author, 
the tliird edition of whose work was printed in the year 1652, and 
in which the recommendation and theory of deep drainage, as ap- 
j)lied by him to water meadows and swamps, are so clearly and 
powerfully laid down, that it would be difficult to give them in 
better language. It is right, too, to assign the merit of discovering, 
or of the earliest assertion of sound practical principles to whomso- 
ever we may consider to be entitled to the praise. The author of 
this work was a Captain Walter Bligh, signing himself " A Lover 
of Ingenuity ; ' it is quaintly entitled ' The English Improver Im- 
proved; or the Survey of Husbandry Surveyed:' with several 
prefaces, but specially addressed to " The Right Honourable the 
Lord General Cromwell, and the Right Honourable the Lord 
President, and the rest of the Honourable Society of the Council 
of Slate." In his instructions for forming the flooding and drain- 
ing trenches of water meadows, the author says of the latter : " And 
for thy drayning trench it must be made so deep that it goo to the 
bottom of the cold spewing moyst water, that feeds the flagg and 
the rush ; for the widenesse of it, use thine own liberty, but be 
sure to make it so wide as thou mayest goe to the bottom of it, 
which must be so low as any moysture lyeth, which moysture 
usually lyeth under the over and second swarlh of the earth, in some 
gravel or sand, or else, where some greater stones are mixt with 
clay, under which thou must goe half one spade's graft deep at 
least. ^ ea, suppose this corruption that feeds and nourisheth the 
rush or flagg should lie a yard or four foot deepe, to the bottom 
of it thou must goe, if ever thou wilt drayn it to purpose, or make 
the utmost advantage of either floating or drayning, without which 
thy water cannot have its kindly operation ; for though the water 
fatten naturally, yet still this coldnesse and moysture lies gnawing 
willini, and not being taken clean away, it eates out what the 
water fattens ; and so the goodnesse of the water is, as it were. 
