389 
Brick-Making. 
will be reduced one inch, the other may lose two ot 
more. Again, the heat of the kiln or clamp, and the si« 
tuation of the bricks as to heat, will vary the diminutiofi 
of the subject to be burnt. It is of consequence, there- 
fore, in the making of sound hard bricks, that the clay 
should be dug two or three years before it is used, in or- 
der that it may be pulverized ; and the oftener it is turned 
and incorporated, the better will be the brickst The 
earth should have sufficient time to mellow, ferment, or 
digest, which will render it more apt and fit to temper ; 
and this operation of treading and tempering ought to be 
performed more than doubly what is usual, because the 
goodness of the bricks wholly depend upon the well per- 
formance of its first preparation, since the earth in itself 
before it Is wrought, is generally brittle, full of extraneous 
matter, which requires to be removed, and as it were with- 
out unity and stability \ but by adding small quantities 
of water by degrees to it, and working and incorporat- 
ing it together, the several parts of it are opened, and by 
being thus exposed to the atmosphere a tough gluey sub- 
stance is formed, which, without such tempering, tread- 
ing and beating, could not have been produced, I can 
only compare this preparation of the soil to that of mak- 
ing bread. When there is a due quantity of water put to 
the flour, and well wrought up together, such bread be- 
comes not only smooth and firm, without having eyes or 
being subject to crumbling, but it eats sweeter and mel- 
lower, and becomes easier of digestion, affording far bet- 
ter nourishment than such as is over- watered, heavy, and 
not sufficiently tempered ; provided the other operations, 
which belong to the making of good bread, such as bak- 
ing, 8cc. be properly performed. 
Bricks thus tempered become solid, smooth, hard, and 
durable ; and one brick thus made takes up nearly as 
much earth as a brick and a half made in the common 
VoL li 3- IX 
