DRAIN TILE for agricultural underground drains are usually circular, and measure from in. to 12 in. in diameter and one foot in length. The following table gives the prices as F. 0. B., at factory say in central Ohio, no allowance being made for breakage : Over 12 in. in diameter the tile are usually 24 in. long.
They can be made of about the same kind of sandy clay as bricks, and are burned sufficiently to include as much porosity and toughness as possible.
There is no reason why tiles of this kind cannot be produced cheaply in almost any neighborhood.
Clay used for the manufacture of building brick will make good drain-tile, care being observed, however, not to have the clay too sandy, as tile made from such clays would be too weak to stand distant shipment. In mining the clay from the bank it should be thoroughly mixed from the top to the bot torn of the clay bank, and some clays when thus mined and mixed give good results when the clay is taken directly from the bank. Some clays require to be dug in the autumn or winter and exposed to the frost, while others may be spaded up and exposed to the action of the air for a longer or shorter time with beneficial results. Clays of all characters used in the
manufacture of drain-tiles will be more or less improved by being run through a pulverizer. It is only through practical test that the best clay can be selected for the manufacture of drain-tile, as it is impossible to foretell the various peculiarities which will be developed in drying and burning various clays. One rule, however, may be laid down, that is that an open, coarse, gritty, sandy, non-plastic clay will not make good drain-tile. The clay used for this purpose should be plastic, smooth to the touch, and possessing such characteristics as would commend it for the manufahure of a good grade of building brick. Any clay selected for the purpose should possess the quality of drying in the open air without damage.