[ 153 ] 
BRICKS. 
I HAVE already treated this subject in my last numbers but 
considering it of great importance, as well as the making of mor- 
tar, which I shall treat of probably in my next, I have carefully 
read over Bergman’s essay de laterum coctione rite instituenda , 
Op. vol. 4. p. 336, and the article Bricks in Rees’s and in the Edin- 
burgh (Brewster’s) Encyclopaedia. I shall therefore copy the 
latter article, adding some further observations of my own. 
BRICK, a kind of facitious stone, made of argillaceous earth, 
formed in moulds, and baked in kilns, or dried in the sun. 
This substance is now in very common use as a material for 
building ; and its importance, in many cases, as a substitute for 
stone, is generally acknowledged. It is lighter than stone, and 
not so subject to attract damp and moisture; and from the quan- 
tities that are now made in Britain, its manufacture has become a 
considerable object of revenue to the state. 
The art of brick making consists chiefly in the preparing and 
tempering of the clay, and in the burning of the bricks ; and as the 
quality of the ware depends very much upon the right perform- 
ance of these operations, we shall present our readers with a short 
sketch of the general process of this manufacture. The earth 
proper for making bricks is of a clayey loam, neither abounding 
too much in argillaceous matter, which causes it to shrink in the 
drying, nor in sand, which renders the ware heavy and brittle. As 
the earth, before it is wrought, is generally brittle and full of ex- 
traneous matter, it should be dug two or three years before it is 
used, that, by being exposed to the action of the atmosphere, it 
may be sufficiently mellowed and pulverised, and thus facilitate 
the operation of tempering. At any rate, it should always have one 
winter’s frost ; but the longer it lies exposed, and the more it is 
turned over and wrought with a spade, the better will be the 
bricks. 
The tempering of the clay is performed by the treading of 
men or oxen, and in some places by means of a clay mill. If the 
operation be performed by treading, which is the common way, 
the earth is thrown into shallow pits, where it is wrought and in= 
corporated together until it is formed into a homogeneous paste, 
which is facilitated by adding now and then small quantities of 
Vol. III. u 
