120 
Iron . 
The furnace being finished, the bottom and sides of it, for 
two feet up the square funnel, receive a lining of common 
bricks upon edge, to prevent the stone from shivering or 
mouldering when the fire comes in contact with it. On 
the front of the furnace is erected a temporary fire-place, 
about four feet long, into the bottom of which are laid 
corresponding bars. The side-walls are made so high as 
to reach the under surface of the tymp-stone ; excepting 
a small space, which afterwards receives an iron plate of 
one and a half inch thickness, by way of a cover : this al- 
so preserves the tymp-stone from any injury it might sus- 
tain by being in contact with the flame. A fire is now 
kindled upon the bars, and is fed occasionally with small 
coals. , As the whole cavity of the furnace serves as a 
chimney for this fire, the draught in consequence is vio- 
lent, and the body of heat carried up is very considerable. 
In the course of three weeks the furnace will thus be- 
come entirely free from damp, and fit for the reception 
of the materials : when this is judged proper the fire-place 
is removed, but the interior bricks are allowed to remain 
till the operation of blowing commences. Some loose 
fuel is then thrown upon the bottom of the furnace* 
and a few baskets of coaks are introduced ; these are al- 
lowed to become thoroughly ignited before more are ad- 
ded. In this manner the furnace is gradually filled ; some- 
times entirely full, and at other times five-eigths or three- 
fourths full* The number of baskets full depend entirely 
upon the size of the furnace : that in the plate will contain 
900 baskets. If the coal is splint, the weight of each bas- 
ket-full will be nearty 1101b, x 900 = 99,0001b. coaks. 
As this quality of coaks is made with a loss of nearly 50 
per cent . the original weight in raw coals will be equal to 
198,0001b. When we reflect that this vast body of igni- 
ted matter is replaced every third day, when the furnace 
is properly at work, a notion may be formed of the im- 
