536 
this diluted earth, and they are so placed in re- 
spect to the mill, that its produce can be dis- 
charged into either at pleasure, by means of 
wooden shoots or spouts. The pugged stuff is 
conducted into one reservoir until it is quite 
filled, when it is turned into the other; and 
while the second is filling, the earthy matter 
subsides in the first, leaving nothing but clear 
water at the surface, and this is carefully drawn 
off by withdrawing pegs, that are placed very 
close, one below the other, from holes in a thick 
plank let into the upper part of the reservoir. 
In this way the water is drained off and runs 
to waste, leaving a finely divided and most 
equable mud in the reservoir, which becomes of 
such consistence by draining, that it can be taken 
up by shovels, put into barrows, and be taken 
away. The discharge of the millis then again 
turned into the first reservoir, which fills, while 
a similar draining and removal of the contents of 
the second is taking place. In this manner the 
clay is more minutely divided and broken up, or 
tempered, than could possibly be done by the 
former process of hand labour, and in its soft 
state, when first moved, is in excellent condition 
for receiving finely sifted breeze, or any thing 
else that may be necessary for improving the 
quality or colour of the brick. After this, all 
that is necessary for rendering the earth fit for 
the moulder, is a few days exposure to the air, 
to make it sufficiently dry for his use; and then 
the process proceeds exactly as before described, 
unless indeed a patent moulding machine should 
be employed, instead of a hand moulder, for 
forming the bricks, and then the compost is de- 
livered to the machine, of which there are several 
varieties, said to produce more compact bricks 
than hand moulding, because greater pressure is 
exerted to compress the clay into the mould than 
can be exerted by a man working the whole day 
through. 
‘he burning of the bricks is an operation of 
great nicety, because, if not burnt enough they 
will be soft and worthless, and, if overdone, they 
vitrify, lose their shape, and often run together 
so as to be inseparable and useless. Accordingly, 
various methods have been adopted for producing 
the due degree of firing, as it is called. In gene- 
ral, bricks are burnt in a kind of building con- 
structed for the purpose, and called a brick-kiln ; 
but in London, the burning constantly takes 
| place in the open air, the bricks being made up 
into immense quadrangular piles, consisting of 
from two to five hundred thousand bricks in 
each. The built kiln is thought by many to 
produce the best bricks, or at all events, a larger 
proportion of good bricks out of any given quan- 
tity, and must certainly consume less fuel, but 
as they are never adopted in the immense brick 
manufactories of London, where no pains or ex- 
pense for conducting the concerns in the best 
and most advantageous manner is spared, this is 
evidence that there must be some objections to 
BRICK-MAKING. 
them, for if they possessed real advantages, there 
can be no doubt but they would be adopted. A 
brick-kiln, as usually constructed, is formed of 
bricks built into a square form like a house, 
with very thick side walls, and a wide door-way 
at each end, for taking in and carrying out the 
bricks ; but these doors are built up with soft 
bricks laid in clay, while the kiln is burning, and 
a temporary roofing of any light material is gene- 
rally placed over the kiln to protect the raw 
bricks from rain while setting, and so made that 
it may be removed after the kiln is fired. The 
English kilns are generally thirteen feet long, 
ten feet wide, and twelve feet high, which size 
contains and burns 20,000 bricks at once. Wood 
is the usual fuel used in these kilns, and they are 
frequently built with partitions, for containing 
the fuel and for supporting the bricks, in the 
form of arches, as will be presently described. A 
brick-kiln has no flue or chimney, as its chief 
purpose is to direct the heat of the fire through | 
the body of bricks piled above it. To effect this 
they must be placed in a particular form with 
great care, and this operation is called setting 
the kiln, and is performed by one or two men 
who understand the business, and to whom the 
raw bricks are delivered in barrows. The form 
of the setting is pretty nearly the same in the 
country-kilns, or London clamps, except that in 
the latter the arches are much smaller, because 
wood is only used for kindling and not for burn- 
ing. The bottom of the kiln is laid in regular 
rows, of two or three bricks wide, with an inter- 
val of two bricks between each, and these rows 
are so many walls extending lengthwise of the | 
kiln, and running quite through it; they are 
built at least six or eight courses high. And 
this is permanent work, or work that remains in 
the kilns that have fire-places built in their | 
floors, or has to be formed every time the kiln 
is set, when it has a flat bottom. The intervals 
between the walls are laid first with shavings, or 
light and dry brushwood, or any thing that will 
kindle easily, then with larger brushwood cut 
into short lengths, that it may pack in a com- 
pact manner ; and, lastly, with logs of split hick- 
ory, or strong burning wood. This done, the 
overspanning or formation of the arches is com- 
menced ; for this purpose every course of bricks 
is made to extend an inch and a half beyond the 
course immediately below it, for five courses in 
height, taking care to skinéle well behind, that is 
to back up, or fill up with bricks against the 
over-spanners. An equal number of courses, on 
the opposite side of the arch, is then set as be- 
fore, and thus the arch is formed, which is called 
rounding, and is a nice and important operation, 
for if the arch fails or falls in, the fire may be 
extinguished, or many of the bricks above the 
arch may be broken. The intermediate spaces 
between the arches are now filled up, so as to 
bring the whole surface to a level, and then the ~ 
setting of the kiln proceeds with regularity until 
