Iron . 
Ill 
Cook Ovens . As the success of several manufactures 
depends on the procuring good coak, I feel pleasure in 
having it in my power to furnish a description of the kind 
of oven made use of in the north of England for coaking 
the refuse small-coal, which, before the adoption of this 
method, was entirely useless. 
At the duke of Norfolk’s colliery near Sheffield, seve- 
ral of these ovens are built on the side of a hill, occupying 
spaces formed within the bank. Each oven is a circular 
building, 10 feet in diameter within, and the floor laid 
with common brick set edgeways. The wall of the oven 
rises 19 inches perpendicular above the floor, and the 
whole is then covered with a brick arch which rises 3 feet 
5 inches more, forming nearly a cone, whose base is 10 
feet, and whose apex is 2 feet, if measured within. This 
opening of 2 feet at the top, is left for the convenience of 
supplying the oven with coal, and to serve as a chimney 
during the process. The whole height of the building 
from the floor is five feet, and the wall, which is 18 inches 
in thickness, is built with good brick, and closely laid,, 
that no air may get in through any part of the work. 
The floor is elevated three feet above the ground, for 
the convenience of placing a carriage under the door- way 
to receive the coak as it is raked from the oven. When 
the oven is thus finished, a strong perpendicular wall of 
common unhewn stone is thrown round it, of about 20 
inches in thickness, and carried up the whole height of the 
oven, forming a complete square. The four comers be- 
tween the circular building, and these outward walls, are 
then filled with soil or rubbish, and well rammed to give 
greater firmness to the work, and the more effectually to 
exclude atmospheric air. 
When these ovens are once heated, the work goes on 
night and day without interruption, and without any fur- 
ther expense of fuel. It is conducted thus : — -Small re- 
