In laving bricks, there are tImr kinds of Boxn ; viz., Flemish-bond, Tlerring-bond, and Garden wall-bond. The two first are principally used in modern brickwork, the others only occasionally.
In a row of bricks laid lengthwise on the length of the wall, is crossed by a row with its breadth in the said length, and so on alternately. The courses in which the lengths of the bricks are disposed through the length of the wall, are called stretching courses, and the bricks, stretchers: the courses in which the lengths of the bricks run in the thickness of the walls, are called heading courses. and the bricks, headers. The other sort of bond, called consists in placing a header and a stretcher alternately in the same course. See BOND, English, &c.
When new walls are to be built into old it is usual to cut a chase, or draw a brick at every other course in the old work, and tooth in the new work. When it is intended to add walls to buildings, these toothings are left.
The most difficult work for a bricklayer to execute is the groining or intersection ofarches in vaults, where every brick has to be cut to a different bed. This and the arches called gauged arches, either circular or straight, require the neatest workmanship. Sonic straight arches are made roughly ; that is, the bricks are inclined each way, parallel to each other, on the respective skewbaeks, or shoulders of the arch, until the soffit-ends of the bricks touch, when the vacant space at top is tilled with two bricks, forming a wedge : this arch, like other straight arches, is constructed on a camber slip, or piece of wood slightly curved on the upper side for centering.
In steining wells, a centre must be first made, consisting of a boarding, of inch or inch-and-a-half stuff, ledged within with three circular rings, upon which the bricks are laid, all headers. The gaps between the bricks towards the boarding are to be filled in with tile or pieces of brick. As the well sinker excavates the ground, the centre with its load of bricks sinks, and another, similarly charged, is laid upon it, another upon that, and so on, till the well is completed ; the centering remaining permanently fixed with the brickwork. This is
the method generally adopted in London, at least where the soil is sandy and loose ; where it is centerings are not requisite. In the country, among many other methods, the following most prevails : rings of timber, without the exterior boarding, are used ; upon the first ring*, four or live feet of bricks are laid, then a second ring, and so on. But this is tin- inferior to the mode above described, as the sides of the brick-work are apt to bilge in sinking, particularly if great care be not taken in tilling and ramming the sides uniformly, so as to keep the pressure regular and equal. In steining wells, and in the construction of cesspools, a rod of brick work will require at least 4,760 bricks.
In winter, it is essential to preserve the unfinished wall, as much as possible, from the alternate efli:cts of rain and frost, than which nothing is more destructive to a building ; the rain by penetrating into the very heart of the bricks and mortar, and the ti'ost by converting the water, so lodged, into ice, expanding its hulk, and bursting or crumbling the materials in which it is contained. The decay of buildings, commonly attributed to the effects of time, is, in reality, occasioned by this operation and counter-operation of the rain and frost, but as, in finished edifices, they have only a verti cal surface to act upon, their effects are not rapidly extended. In an unfinished wall, there is a horizontal surihee, by which both rain and frost find an easy access into the body of the work ; care must therefore be taken to exclude them, by a sufficient covering, as soon as the frost or stormy weather sets in, either of straw, which is most usually employed, or of weather-boarding, placed in the form of a stone coping, so as to throw off the water equally on either side : but in the latter ease, it is advisable to have a good body of straw under the wood, as no precaution can be too great, for the security and strength of the work.