OO ON DRAINING. 



of iron deposit at the outfalls of these drains. Time and 

 observation, assisted by an analysis of the issuing- waters, 

 which has alread}' been commenced, and the drawing- the 

 attention of chemists g'snerally to the subject, may, I hope, 

 by enabling us to detect causes, teach us how to improve 

 effects. The subsoil g-enerally in Drayton Manor Park con- 

 sists of g'ravel intermixed with fine and very heavy sand 

 alternating- with, or broken in places by, a marly clay very 

 retentive of water. It contained much water, our test holes 

 standing" full in the winter, or within eig'hteen inches of the 

 surface throughout. It was chiefly by the pickaxe that the 

 trenches had to be opened, spades being- of little use in the 

 g-ravels. The sides fell in and closed so much that it was 

 difficult, and in some parts impossible, to keep an entire line 

 of drain open before the pipes were oblig-ed to be laid, so 

 that the worst parts had to be done by instalments, the pipes 

 being' laid and covered up as the work proceeded ; for, if not 

 so done, the spewing- sand was forced up from the bottom 

 and throug-h the sides by the pressure of water. All was 

 secure, however, when- the collared pipes were laid and 

 covered in. One drain, about 105 yards long", was laid in a 

 quicksand, by iising' inch pipes completely sheathed in 

 another larger pipe, and no packing- or cover was employed. 

 This drain, which is about six feet deep, has never exhibited, 

 at its outfall, a g-rain of sand • the water is beautifully pel- 

 lucid, and has maintained a discharg-e, varying' however, 

 with rain or droug-ht, of about two g-allons per minute. I 

 conceive this method of sheathing- pipes to be capable of 

 forming- a permanent drain throug-h any species of quicksand 

 or loose soil ; packing- may be a useful and even necessary 

 adjunct in certain very fluid and fine media, but when a 

 drain thus formed is carefully laid and filled in, my belief is 

 that it will resist the entrance of all matter, except water. 

 To use the apt expression of one of my workmen, " nothing- 

 else can g-et in when the water sig-hs into the drain so 

 quietly." 



A second cause of obstruction to drains described by Mr. 

 Parkes, is the entrance into them of the roots of trees and 

 plants. Probably no species of close under-drain yet con- 

 structed can be considered to be absolutely safe from roots, if 

 laid within the rang-e of their travels; and how far these often 

 extend from the parent tree is well known to every ag-ricul- 

 turist. The minutest orifice siiffices to afford them entrance. 

 Yet they seem capricious in their invasion. Mr. Parkes has 



