the production of fine grades of sheet iron from
charcoal pig metal, by puddling and in knobbling fires. The usual weekly
product of the mill has been thirty tons of No. 3 tin plates and fifty
tons of No. 24 to twenty-eight sheets.

The well was bought by this firm for $1,000, and the gas is led across
the river, a distance of 500 feet, through a three-inch pipe. It is
distributed through half-inch pipes, and at a pressure of about
forty-five pounds per square inch, to several of the furnaces. No
essential alteration in any of the furnaces has been found necessary in
the use of the gas fuel, except to brick up the fire bridge and to put
in the gas and air pipes. The old grate used for coal is loosely covered
with bricks and cinder, so that a slight percolation of air may take
place through them. The gas is admitted through a half-inch pipe, and
blows toward the fire-bridge through eighteen or twenty one-eighth inch
jets. The air is blown in, at about 2 lbs. pressure, through two one and
one-eighth-inch jets, obliquely down upon the centre of the hearth, and
a very perfect combustion is obtained. A great improvement is effected
in the quality of the product of the puddling furnaces by the combined
action of the gas and air blast. The air is blown in during the melting,
but it is then shut off until the boiling begins. It is then turned on
full, and a violent boiling action is maintained without any rabbling.
Many advantages result from the use of this fuel. The product of the
mill has increased about thirty per cent., from sixty to seventy tons of
coal are saved daily, besides the labor necessary to fire with it, and a
poorer quality of iron can be used in making the tin plate. Thus the
iron now used is credited to the furnace at $45 per ton, while charcoal
blooms have cost $80. These are certainly enormous advantages, and
though every mill cannot have a permanent gas well, it must be more
economical to produce such results by making coal into gas than to
continue using it in the solid form. The gas at Leechburg is used in
fourteen furnaces and under seven boilers. Its composition is carbonic
acid, 0.35; carbonic oxide, 0.26; illuminating hydrocarbons, 0.56;
hydrogen, 4.79; marsh gas, C H_{4}, 89.65; ethyl hydride, C_{2} H_{6},
4.39; specific gravity, 0.558. This analysis shows about 57 per cent. of
carbon and 42 per cent. of hydrogen. If the well discharges one million
cubic feet of gas daily, it would weigh about sixty