In such a large country as Australia there must needs be a great variation in the quality of bricks available for building, but while this is so it may be laid down as a general rule that the bricks are extremely good. Particularly is this the case with the steam-pressed machine-made Melbourne bricks, which for soundness combined with good uniform red colour can hardly be excelled.

These bricks are made from " Rock," which offers a surprise to the visitor who has in mind the clay digging, tempering, hack drying, and clamp burning of many of the English brickfields, though it is somewhat similar to that from which the Ruabon bricks are made. The popular term is "Reef," but this is, strictly speaking, not correct. These rocky formations are of such a character that when decomposed they become clay, and are taken by the brickmaker, ground, slightly wetted, steam pressed, and passed at once to the Hoffman kiln, from which they emerge sound, hard, and durable, weighing about 8 3/4 lbs. each. They are put upon the market at about 38s. per thousand.

With bricks of this character Melbourne has been provided with 120,000 houses, large buildings, and stores. And what is true of Melbourne is also in a somewhat lesser degree true of the other leading cities.

In country districts there are scattered brickfields, working for the most part on more primitive lines with hand presses and ordinary kilns.

So far there has been a somewhat limited use of the moulded brick. This has been partly due to the excessive hardness of the brick-making materials, and the consequent difficulty in cutting and adjusting small returns, angles, and special parts required to properly complete any intricate design. Of late years, however, this field of production has been considerably opened up, and the manufacture of excellent architectural terra cotta, within range both of Melbourne and Sydney, has made purely brick treatment in design possible.

The general colour of the Australian brick is red, but for decorative purposes white bricks are made in limited quantities, and a very good quality of dark brown brick is also manufactured from material highly charged with iron. There is nothing in Australia, however, to correspond in colour with the London stock brick.

In the execution of brickwork the London practice is generally followed with regard to wall thickness, footings, etc. In the cities, where the Building Acts are mostly based upon the London laws, this is specially the case. There is, however, a very marked preference for the hollow wall rather than that of a solid character, on account of excessive heat and heavy rains, it having been found that a 2-inch cavity has a marked influence in reducing temperature and securing internal freedom from dampness. This hollow wall work leads to the use of garden-wall bond, and the adoption of the stout galvanised wire or hoop iron tie, the cast-iron variety being but little used.

For solid work of a heavy character, English bond is used, as well as a variety called "Colonial Bond," consisting of three rows of stretchers and one row of headers, which makes easily laid, sound walling for warehouse work.

Brickwork 294

Fig. 235.

Flemish bond is used for the best class of facing work where solid walls are required.