weeks, or 850 tons per week, and of 134 tons in one day from a single
furnace.

From the United States we have authentic accounts of an average
production of 1,120 tons per furnace per week having been attained,
and that even this great output has lately been considerably exceeded
there. Both as to consumption of fuel and wear and tear, per ton of
iron produced, these enormous outputs are attended with economy.


HEAT OF THE BLAST.

In the case of the Consett furnace they were obtained although the
heat of the blast was under 1,100° Fahr., while heats of 1,500° to
1,600° are not uncommon at the present day in brick stoves, thanks to
the application of the regenerating principle of ex-president Sir W.
Siemens.

But an economy which promises to be of great importance is now sought
in the recovery and useful application of those constituents of coal
which, in the coking process, have hitherto been lost; or, as an
alternative, in a similar recovery in those cases in which the coal is
charged in a raw state into the blast furnace, as is the practice in
Scotland and elsewhere. This recovery of the hydrocarbons and the
nitrogen contained in the coal, and their collection as tar and
ammoniacal liquors, and subsequent conversion into sulphate of ammonia
as to the latter, and into the various light and heavy paraffin oils
and the residual pitch as to the former, have now been carried on for
a considerable time at two of the Gartsherrie furnaces; and they are
already engaged in applying the necessary apparatus to eight more