The machine consists usually of a strong iron chest, with a hinged cover, into which the clay is placed, having a piston moving in it, connected by a rod or bar, having cog-teeth, with a cog-wheel, which is moved by horse or hand power, and drives the piston forward with steadiness, forcing the clay through the openings in the die-plate. The clay issues in continuous lines of pipe. The machines most in use in this country are connected directly with the pug-mill, and as the clay is pugged, it at once passes into the box, and is pressed out as tiles. These machines are usually run by horse-power. Mr. Barral, in his voluminous work on drainage,(25) describes, as follows, a cheap hand machine which can be made by any country wheelwright, and which has a capacity of 3,000 tiles per day (Fig. 44): "Imagine a simple, wooden box, divided into two compartments. In the rear compartment there stands a vertical post, fastened with two iron bolts, having heads at one end, and nuts and screws at the other. The box is thus fixed to its support. We simply place this support on the ground and bind its upper part with a rope to a tree, a stake, or a post. The front compartment is the reservoir for the clay, presenting at its front an orifice, in which we fix the desired die with a simple bolt. A wooden piston, of which the rod is jointed with a lever, which works in a bolt at the top of the supporting post, gives the necessary pressure. When the chest is full of clay, we bear down on the end of the lever, and the moulded tiles run out on a table supplied with rollers. Raising the piston, it comes out of the box, which is again packed with clay. The piston is replaced in the box; pressure is again applied to the lever, and so on. When the line of tiles reaches the end of the table, we lower a frame on which brass wires are stretched, and cut it into the usual lengths." [Fig. 44 - CHEAP WOODEN MACHINE.] Fig. 44 - CHEAP WOODEN MACHINE. The workmen must attend well to the degree of moisture of the clay which is put into the machine. It should be dry enough to show no undue moisture on its surface as it comes out of the die-plate, and sufficiently moist not to be crumbled in passing the edge of the mould. The clay for small (thin) tiles must, necessarily, be more moist than that which is to pass through a wider aperture; and for the latter there may, with advantage, be more sand in the paste than would be practicable with the former. After the tiles are cut into lengths, they are removed by a set of mandrils, small enough to pass easily into them, such as are shown in Fig. 45, (the number of fingers corresponding with the number of rows of tiles made by the machine,) and are placed on shelves made of narrow strips sawn from one-inch boards, laid with spaces between them to allow a free circulation of air. [Fig. 45 - MANDRIL FOR CARRYING TILES FROM MACHINE.]