This subject deserves special notice. We have said that the New England
manufacturers at first used wood only, which was prepared by being
split into equal lengths, with an average diameter of two inches, and
then kiln-dried to dispel the sap and moisture. This fuel was supplied
to the furnace at opposite fire-holes, a stick at a time, which was a
laborious and heating process.
Subsequently, a furnace was built at South Boston, over a cave, and
unkilned wood was used in clefts. This saved one quarter in fuel, but
it used up the pots so rapidly as to prove to be no economy in the end.
After the development of the Virginia coal mines, our furnaces were
altered to use coal, which proved to be more convenient and less costly
than wood. The Pictou and Cumberland mines also increased the supply;
and at present all the furnaces in New England, with one exception, are
run with this last-named fuel.
The various experiments made to economize fuel for the "glory-holes,"
as the workmen call the working places above the furnace, are well
known. For many years the prepared wood we have spoken of was used.
Then resin in a powdered state was added, which was both inconvenient
and dangerous,--it having caused the destruction by burning of two
glass-houses. This risk was finally overcome by the introduction of an
invention which used it in a liquid state. But the demand for resin
became so great as soon to more than double its price. This led to the
substitution of coal tar, which was in use until science discovered its
latent virtues for other purposes, and largely increased the original
cost of the material. Indeed, at first the gas companies had considered
it of no value, and had thrown it away by thousands of barrels.
Combined with dead oil it is still used by glass-makers, but at greatly
enhanced prices.
The Cape Cod Glass Company have had in use for several years a Delano
patent furnace-feeder, which enables them to use both hard and soft
coal, as either is cheapest, and consumes the smoke and gas of either
fuel, thus doing away all annoyance to the neighborhood. Theretofore
every attempt to run working places with hard or soft coal had failed
on account of the noxious gases set free, which injure the color of the
glass. But owing to the intense heat created by the Delano patent, the
furnace consumes these gases, and gives a quick fire polish to the
various articles finished therein.
As our native supplies of hard and soft coal are inexhaustible, there
is no likelihood of an increase in the price of the present fuel so as
to necessitate, as heretofore, a substitution of some cheaper article,
especially as the discovery of petroleum tends to cheapen coal by a
diversion of a portion of its consumption to that useful mineral oil.