—g.[477.] Adjustment of the core in the mould.
—g.[478.] Cupola furnace. It is 3 feet wide within, and 131⁄2 high.
m m, solid body of masonry, as a basis to the furnace.
b b, octagonal platform of cast iron, with a ledge in which the plates a a a a are engaged.
a a, eight plates of cast iron, 1 inch thick, absolutely similar; only one of them is notched at its lower part in c, to allow the melted metal to run out, and two of the others have six apertures g g g, &c. to admit the tuyères.
c, orifice for letting the metal flow out. A kind of cast iron gutter, e, lined with loam is fitted to the orifice.
d, hoops of hammered iron, 41⁄4 inches broad; one half of an inch thick for the bottom ones; and a quarter of an inch for the upper ones. The intermediate hoops decrease in thickness from below upwards between these limits.
e, cast iron gutter or spout, lined with loam, for running off the metal.
f f, cylindrical piece of cast iron, for increasing the height and draught of the furnace.