In § I of this chapter we shall study the different phases of the manufacture of bricks: moulding, drying, and firing; § 2 will be reserved for the examination of the shapes, dimensions, and decoration of bricks; and in § 3 we shall point out their uses and their applications as well as their history.
From the most distant antiquity this moulding has been performed by hand by methods which probably differ very little from that which is called Flemish or Walloon. The simplicity of this process, the few tools required, its small cost, the absence of large expenses of installation, and the great output which it allows, were calculated to cause it to be considered as the only one possible. And in fact it is admirably suited for the manufacture of bricks which are intended for large buildings distant from centres of production but near beds of clay. The work is carried on on the spot. Small brickworks, and even large ones, have employed and still employ this process to a great extent, but it is no longer the only one. Nearly a hundred years have passed since those hand machines appeared which produced bricks by pressing the clay in moulds when it came from the pit. In this way the extraction of clay for weathering was avoided, and a considerable economy effected. No doubt the bricks so made are not as good as those made by hand, but for what are called native bricks the difference was not very noticeable.
Another valuable advantage was that the work and the presses were no longer so much subjected to the inclemencies of the summer. We know in fact that everything in the Walloon method is done in the open air, and thus a rainy summer causes frequent stoppage of work and consequent loss. We have no precise documents as to the invention of machines for making bricks by expression, and we do not know who recommended the use of die machines, but we may say that these discoveries date from the beginning of the century. For a long time the use of machines was very little extended; but the invention and the increasing use of hollow products and mechanical tiles, the manufacture of which requires machines, have considerably augmented the number of factories using machinery. This extension has been encouraged by the constantly increasing consumption of bricks, and the facility of transit which allows the distribution of the goods even outside the sphere of action of the factory.
Finally, the requirements of customers, who have gradually become used to fine machine-made productions and will have no others, have something to do with the fact that in large towns and in factory buildings hand-made bricks are no longer to be seen.
But in a great number of local works the primitive method, especially for the so - called native bricks, is the only one employed on account of its simplicity.
There are then two quite distinct processes of brick manufacture -
1. The process by hand carried out in the open air; 2. the process by machinery carried out in the open air or in factories.
The latter, as we shall see later on, is subdivided under several headings according to the way in which the machines work, and according as they are driven by hand, by animal power, or by steam.