This is done with special bricks, very hard and sometimes vitrified. Their surface is rough or striated when they are used flat (Fig. 251), and bevelled when placed on edge (clinkers) (Figs. 3 36, 337, 338).
The bricks are laid on a bed of mortar placed where the paving is to be done and sloped for the proper draining off of water. The adhesion of the bricks to the mortar is increased by the use of fluted bricks (Fig. 341).
For stables and wash-houses where large quantities of water are thrown down, special bricks (Fig. 343) are used, which, placed end to end, form a trench and so help the water to run off.
Bricks in the shape of gutters (Fig. 339) are also made to collect the moisture on the pavement (Fig. 342), lateral hollows (Fig. 340) cut in some of the bricks allowing the water to come in from other directions. These kennel-stones are either open or closed with a flat brick (Fig. 344).
Figs. 336 to 344. Various Paving Bricks.
Fig. 349. First Layers.
Fig. 350. Second Layer.
Fig. 351. First Layer.
Fig. 352. Second Layer.
Figs.. 345 to 148. Gourlier Bricks for Chimney Conduits.
Besides the hollow pottery conduits, called "boisseaux" and "wagons," special bricks are used, called Gourlier, after the name of their inventor. They are in four shapes (Figs. 345 to 348), which are alternated in every layer in order to interrupt the joins. Figs. 351 and 352 represent two layers for a single conduit, and Figs. 349 and 350 the two different layers, repeating themselves from top to bottom, for two neighbouring conduits.
Ordinary bricks, by means of special dressing, may be used to decorate cornices, but, unless the bricks are cut, the effects are necessarily limited to straight lines. It is better to use solid, or preferably hollow, moulded bricks (Figs. 353 to 355), because they are less liable to lose shape in drying.
Figs. 353 to 358. Hollow Bricks for Cornices.
The section (Fig. 357) and elevation (Fig. 358) represent an application of the three types above described, ornamented with knobs (Fig. 356).
The differences in the colours of bricks are made use of in the decoration of cornices, openings, and walls, by arranging them in the most varied patterns, some examples of which are shown in Figs. 359 to 364. The resources offered by brickwork for decorative purposes were well exemplified at the
Figs. 359 to 364. Various Dressings with White and Red Bricks.
Exhibition of 1889, in the machine gallery, in the pavilion of the Minister of Public Works, and in many other constructions.
Figs. 365 to 367. Open-work Walls for Balustrades.
If to the natural colours, which are necessarily limited, we add the gamut of the artificial tints, the variety of effects is increased.
By combining bricks in different ways, and by using them alone or with stone, we can get an infinite number of styles of dressing, which may be used for open-work walls in their varied applications: window supports, string-courses, balustrades, etc. (Figs. 365 to 367).