This mill consists usually of a vat, or circular vessel, fixed on a timber frame; an upright iron axle is placed in the centre of the vat, and carries some iron plates, or rakes with teeth, to stir up the soft clay when placed in the mill: this axle is turned round by a horse harnessed to a horizontal shaft which proceeds from the axle. The clay being put into the vat, the rakes or _knives_ complete the incorporation of the ashes, and thoroughly temper the whole mass, which is gradually squeezed out through a hole in the bottom of the vat. A better kind of mill is used in tempering the material for the better bricks; it only differs, however, in being larger. An iron harrow loaded with weights is dragged round in a circular pit lined with brick-work. The clay in this case is diluted with water sufficiently to allow of the stones sinking to the bottom; and the fluid is drawn off into pits, where it is left to settle and thicken, to the proper consistence. The prepared clay is first separated into masses, each large enough to make a brick, by the _feeder_, or assistant, who sands the pieces ready for the _moulder_; the _mould_ is an open rectangular box, the four sides of which are made to separate from the bottom, to allow of the brick being turned out. The bottom is now made with a lump raised on it, by which a slight depression is formed on one side of the brick, to admit a mass of the mortar being received and detained in it when the wall is built. The moulder takes the piece of clay prepared for him, and dashing each into the mould so as to cause it to fill it, removes the superfluous quantity by means of a flat piece of wood which he draws across the open side of the mould; this _strike_ is kept in a bowl of water to wet it, and prevent the adhesion to it of the clay. The man then lifts off the sides of the mould, and deposits the brick on a flat _pallet-board_, and this is removed by a boy who ranges the bricks on a lattice frame set sloping on the barrow in which they are to be taken to the field to dry; fine sand is strewed on the frame and over the bricks, to prevent their adhering together. The bricks are taken to the field, and piled in long lines called _hacks_. This is a nice operation, as the soft bricks, if handled roughly, would become twisted, and rendered useless; the bottom course of bricks is raised a few inches to keep it from the wet; and the ground is prepared to receive them by being covered with dry brick-rubbish or ashes, and raked smooth. The bricks are set alternately in rows lengthwise and crosswise, with intervals between them of an inch or more, to allow a thorough circulation of air: the hack, when raised about a yard high, is covered over with straw to throw off the rain. If the weather be favourable, ten or twelve days are enough to dry the bricks in the hacks sufficiently to prepare them for burning, but they should be thoroughly dry, or the subsequent process will fail.