THOROUGH-DRAINING. 105 



this be tlie natural tendency of plants, tliere can be no doubt 

 that, in proportion as we draw oft" the stagnant water by 

 deep-draining-, and make the land permeable to atmospheric 

 influence, and accessible to the roots of plants, in the like 

 proportion shall we increase its productive powers ; while, 

 by lessening- the evaporation, and ridding the earth of 

 noxious vapours, we shall contribute materially to the 

 warmth, dryness, and salubrity of our atmosphere. I now 

 beg to thank you, gentlemen, for the very attentive hearing 

 with which you have favoured me, in an address which may 

 have appeared to you rather desultory ; and if any one has 

 objections to make to my statements, or explanations to ask 

 for, I shall be most ready to attend to him. 



A question was asked by Mr. Stei)henson as to the size of 

 pipes which Mr. Grey deemed sufficient to contain the water 

 from drains thirty to thirty-three feet apart. 



Mr. Grey : — I consider pipes of one inch diameter gene- 

 rally sufficient ; more, indeed, than ever will be filled. Look 

 at the quantity of water vented by a lead pipe of much 

 smaller dimensions in your stable-yard. But it is an object 

 to admit air, as well as to convey water, and therefore I am 

 not strenuous for very small pipes : that is more a question 

 of economy. If your drains are, say 300 yards long, begin 

 with one-inch pipes for 100 yards, then take one inch and a 

 quarter, and so go on increasing as you approach the outlet ; 

 and your carry-drain may be made of a single large pipe, or 

 of three smaller ones, two side by side, and one -above them, 

 which makes a safe and excellent main drain ; the top pipe, 

 however, being seldom needed. 



IMr. Smith inquired if Mr. Grey woidd recommend to 

 put small stones over the pipes, or straw, or any other 

 substance. 



Mr. Grey said the object was to draw the water, not along 

 the surface and down into the top of the drain, but by a 

 downward fall through the soil into the bottom of the drain, 

 when it would insinuate itself into the joints of the tiles or 

 pipes ; he therefore considered that the firmest stuft" was 

 best for the top of the pipe. He disliked to see straw 

 carried out for that purpose, because it robbed the fold-yard 

 and the dung-heap, and did, as he thought, no good. He 

 had had occasion to drain a good deal of thin moorish land, 

 where it was necessary to cut through a sharp yellow sand : 

 he had laid heather, which is a very imperishable article, on 

 the tiles in that case, to prevent the sand from being washed 

 into them. 



