Nearly all houses are built of bricks, as they are less expensive than stone, and more durable than wood, besides being less liable to be burnt. Walls of brick may be formed of any required thickness, and as the length of a brick is twice its breadth, they admit of being so laid that the wall shall not part in pieces, which would be the case if laid as in fig. 1, as the seams of mortar run continuously through the wall, which in bricklaying is always avoided, by different methods. Formerly bricks were laid in what was called “English bond” (fig. 2), but this is not now used, “Flemish bond” (fig. 3) having superseded it. The mortar with which bricks are laid is made of lime and sand, mixed with water to a convenient consistence; it sets quickly, hardens with age, and resists the action of rain and time. The ordinary mode of laying bricks is to stretch a line from end to end of the course on which they are to be laid; the surface of the under course is spread for a short distance with mortar, and the bricks intended to form the outer surface of the wall are laid first, in an exact line with the cord, the “plumb” (fig. 4) being frequently used to ascertain if they are perpendicular. The “plumb” is a piece of board with a notch at the centre of the top, and a hole, also in the centre, near the bottom; a piece of cord is passed through the notch, with a leaden ball attached, which swings in the hole as the plumb is placed at the side of the wall. The ball of lead just falls in the hole if the wall is upright, and in this way a wall may be built to any height, exactly perpendicular. The corner of brickwork where windows occur, is called the “arris,” and has to be made upright both in front and at the side. When very thick walls are to be made (as in railway cuttings), the outer surface and back of the walls are laid in the usual way, the space between is filled with a layer of bricks, and thin liquid mortar is poured on and scraped about with a sort of hoe till the spaces between the bricks are all filled up and the surface left level, when another course is laid in the same manner. Fig. 5 is a trowel, or instrument used to take up and spread out the mortar, and fig. 6 is the hod, in which the labourer carries supplies of bricks or mortar to the spot where the bricklayer is working. STONE CUTTING. Illustration: STONE-CUTTING. Illustration: FIG. 1. (‡ IRON PICK.) Illustration: FIG. 2. (‡ CHISEL AND SCRAPER.)