Fig. 26.—Draining-Bricks.
So lately as 1856, tiles were brought from Albany, N. Y., to Exeter, N. H., nearly 300 miles, by railway, at a cost, including freight, of $25 a thousand for two-inch pipes, and it is believed that no tiles were ever made in New Hampshire till the year 1857. These facts will soon become curiosities in agricultural literature, and so are worth preserving. They furnish excuse, too, for what may appear to learned agriculturists an unnecessary particularity in what might seem the well-known facts relative to tile-drainage.
Drain-tiles are made of clay of almost any quality that will make bricks, moulded by a machine into tubes, or into half-tube or horse-shoe forms, usually fourteen inches long before drying, and burnt in a furnace or kiln to be about as hard as what are called hard-burnt bricks. They are usually moulded about half an inch in thickness, varying with the size and form of the tile. The sizes vary from one inch to six inches, and sometimes larger, in the diameter of the bore. The forms are also very various; and as this is one of the most essential matters, as affecting the efficiency, the cost, and the durability of tile-drainage, it will be well to give it critical attention.
THE FORMS OF TILES.
The simplest, cheapest, and best form of drain-tile is the cylinder, or merely a tube, round outside and with a round bore.
Figs. 27, 28, 29.—Round Pipes.