The art of bricklaying now demands notice. To ensure a strong wall, the bricks must be so laid that those in one course break joint with those in the course below; in other words, the bricks must be thoroughly bonded together. The bond must tie the wall together both longitudinally and transversely. There are several varieties of bond, of which the principal are: -

1. English bond (Fig. 38), consisting of alternate courses of headers a a and stretchers B b; this is the strongest form of bond, and does not provoke scamping.

2. Garden-wall bond or Scotch bond, consisting of one course of headers to every three, four, or five courses of stretchers; this is a modification of English bond, used chiefly for internal walls.

3. English cross bond (Fig. 39), another modification of English bond, effected by moving each alternate course of stretchers a half-brick on one side of the other courses of stretchers, so that the joints in the alternate courses are plumb over the centres of the bricks in the other stretching courses; this has rather a pretty effect, and is not uncommon in Holland and Belgium; the Chateau at Spontin, and the Chateau Freyr near Dinant, are excellent examples.

4. Single Flemish bond (Fig. 40), consisting of header and stretcher alternately in each course on one side. of the wall, and of alternate courses of headers and stretchers on the other side; this bond necessitates a considerable number of half-bricks or false headers, and is deficient in strength.

5. Double Flemish bond, consisting of header and stretcher alternately in each course on both sides of the wall; this also is a weak kind of bond, being deficient in headers, and necessitating a great proportion of half-bricks.

6. Stretcher bond or chimney bond, consisting wholly of stretchers, and applicable only to half-brick walls, such as partitions and chimneys.

7. Header bond, consisting wholly of headers, and applicable only to 9-inch walls; it is weak and does not look well, but is useful for walls of quick curvature, where the expense of specially-shaped bricks must be avoided.

A glance at the illustrations will show that, in order to make the bricks break joint with each other, it is necessary to insert near the angles narrow pieces one-fourth the length of the ordinary brick, as shown at cc; these are known as closers, and should always be placed next to the angle brick. Instead of the quarter-brick closer a three-quarter brick is sometimes placed at the angle of the wall, as shown at D D in Fig. 39.

Fig 38 English Bond.

Fig 38 English Bond.

Fig. 39  English cross Bond.

Fig. 39 -English cross Bond.

Fig 40. Single Flemish Bound.

Fig 40. Single Flemish Bound..

Sometimes facing-bricks thinner than the bricks used in the remainder of the wall are for aesthetic reasons preferred. It is in such cases impossible to make a really good bond between the two kinds of brick, as headers can only be inserted when the facing and backing have risen to the same level. In Fig. 41 this occurs only once in every six courses of face-bricks. If, as will probably be the case, Flemish bond has been adopted, then only alternate bricks in every sixth course will l»e headers. Thin facing-bricks may, however, be used without detriment for the facing of hollow walls, and also of walls in which a small cavity is formed and filled with asphalt or other composition.

For the formation of angles other than right angles, purpose-made bricks should be obtained of the desired shape; except of course for rough work, when ordinary bricks roughly cut to the required angle may be used. Bricks with one angle rounded, and known as bull-nosed bricks, are largely used for the salient angles of internal walls where plaster is not adopted; they are especially to be desired in glazed brickwork, as the sharp angle of a square brick is easily chipped by a blow. The shaping of the brick, however, need not be confined to a simple curve; splays, and moulds of various kinds, may be used. In hospitals the re-entrant angles of the rooms are now generally formed curved instead of square, special bricks being used for the purpose; the curve facilitates dusting and washing, and may with advantage be adopted in sculleries, water-closets, and other domestic offices.

Sill-bricks should be jointed with Portland-cement mortar; so also should plinths, string-courses, copings, and other projecting members, and the brickwork of parapets and chimney-stacks.

Glazed bricks are often laid in bricklayers' putty, which is a mixture of fine white sand or marble dust, and pure lime which has been slaked in a large quantity of water, strained, and allowed to stand till it has become of the consistency of thick cream. Nowadays Portland cement is often used mixed with fine sand, and makes better work. The joints in glazed brickwork, especially in hospitals, are sometimes painted with enamel paint to render them impervious. As the joints in glazed brickwork are always thinner than those in the brick backing, the glazed bricks should be about one-eighth of an inch thicker than the common bricks, in order that the courses may be kept level and proper bond obtained.

Fig. 41. Thin fac las bricks with Com mon Brick Backing.

Fig. 41. Thin fac-las bricks with Com-mon Brick Backing.