Agricultural drainage : a retrospective of forty years experience / J. Bailey Denton.
- John Bailey Denton
- Date:
- 1883
Licence: Public Domain Mark
Credit: Agricultural drainage : a retrospective of forty years experience / J. Bailey Denton. Source: Wellcome Collection.
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![under the influence of a passage of air causing more rapid evaporation of moisture than would otherwise occur, one of the benefits of draining is cheaply acquired by air drains, and for the denser clays it may possibly be a desirable thing to do, but in the porous soils it would appear that no advantage is gained by it. Many persons regard the admission of air to drains as an impediment rather than an aid to drainage, but I have not yet seen that assertion proved. The use of collars is by no means general, although those who have Collars, used them speak highly of their advantages. Except in sandy soils, and in soils subject to sudden alteration of character—in some of the deposits of the Red Sandstones and in the clayey subsoils of the Bagshot sand district, for instance—collars are not found to be essential to good drainage. In the north of England they are used but seldom, and in my opinion much less than they ought to be; but this opinion, it is right to state, is opposed in numerous instances of successful drainage by men of extensive practice ; and as every cause of increased outlay is to be avoided, the economy of collars is doubtful. In all the more porous subsoils in which collars have not been used, the more successful drainers increase the size of the pipes in the minor drains to a minimum Size of pipes size of 2 inches bore. [At the present moment, 1883, we never use jf^'^'^o' any pipes less than 2 inches in bore.] Before dismissing details it will be opportune to remark that the Outlets, proper selection of outlets, and a care for their preservation, are as pre- eminently essential to good and satisfactory work, as anything belonging to drainage. Too many outlets are objectionable on account of cost of their maintenance; too few are objectionable because they can only exist where there are mains of excessive length. A limit of twenty acres to an outlet, resulting in an average of perhaps fourteen acres, will appear by the practices of the best drainers to be about the proper thmg. [The outlets (which should be iron pipes, set in masonry) I am putting up for the General Land Drainage Company are made by Messrs. Barford & Perkins, of Peterborough.] Each outlet, which should discharge into an outfall watercourse with Plans of a drop of some inches, should be numbered by means of an iron Dlate With date as well as number, let mto masonry, and the numbers should be figured on a plan of the lands, having the site of every outlet and the position of every drain marked upon it. I submit upon the third and last point, the arrangement and direction of drains, that the results of the practice of the last few years have](https://iiif.wellcomecollection.org/image/b21782568_0037.jp2/full/800%2C/0/default.jpg)
