FURIES
725
FURNACE
is the Russian sable, some of the finest of which sell for over $200 apiece. Among other furs now sold are those of the black bear, badger, beaver, chinchilla, ermine, fox, leopard, marten, mink, raccoon, skunk, squirrel, wolf and wolverine. The usual mode of dressing furs is by steeping them in liquor for a short time, after which the pelts are "fleshed" over a sharp knife to get rid of the excess of fat, etc. and then dried off; they are next trodden by the feet in tubs of warm sawdust and common butter, by which the pelt or leather is made supple; the skin is then finished in dry sawdust and beaten out.
Furies, The or Erinys, Dirae and Eu~ menides, were, in Greek mythology^ female divinities who were avengers of iniquity. These goddesses were daughters of Night, or, according to another myth, of Earth and Darkness, who sprang from the blood of the mutilated Uranus. Their number varied, but they usually are spoken of as three: Megaera (the grimly jealous), Alecto (the unwearied persecutor) and Tisiphone (the avenger of murder). Nothing, it is said, escaped their sharp eyes as they pursued the evil-doer with speed and fury% permitting him no rest. They were variously represented, at one time as female figures of odious aspect, clad in black, sometimes winged, with hair formed of vipers and carrying a serpent, a knife or a torch; at another time, they were characterized as divine beings, whose functions were to punish neglect of duty and breach of faith, yet who were looked upon as preservers of a high morality and hence were called Eu-menides or the well-minded goddesses. Their abode was Colonos, near Athens.
Fur'nace, in general any arrangement in which heat is produced by burning fuel. It usually is a structure of iron or brick, lined with fire-brick to withstand intense heat. Furnaces are used for domestic purposes, as heating and cooking; for motive-power, as for steam-boilers; and for metallurgical and chemical processes. For heating and power purposes, see HEATING AND VENTILATION and BOILERS.
Furnaces used Jn metallurgy are of two kinds: (a) those in which the burning fuel and material to be heated are mixed and (b) flame-furnaces, where the fire-grate is separate from the flame-chamber or working-chamber in which the materials to be heated are placed. The common blacksmith forge is a simple example of the first class. Blastfurnaces and cupolas also belong to this class. A blast-furnace is a vertical structure in which ores of iron are roasted and smelted in contact with suitable fuel and fluxing-materials. The burning of the fuel is accelerated by a blast injected under pressure through openings called tuyeres near the bottom. The dimensions of the furnace are such as to pro-
duce a thorough mixture and heating of the
materials. In all modern blast-furnaces the
blast is heated to a high temperature before
being forced into the furnace. Biast-fur-
naces are from 60 to 100 feet high and from
20 to 25 feet
in diameter at
the middle.
The narrowest
parts are at the
bottom and
top. The fuel
and the ore
with certain
fluxes, usually
limestone, are
introduced in
alternate layers
at the top. The
melted metal
fathers at the ottom and is drawn off to be cast into "pigs" or, in many modern f ur-n a c e s, to be passed directly to the Bessemer converters to be made into steel. There also is formed a slag at the bottom from the melting of the limestone and earthy matters of the I ore. This slag floats on the iron and is drawn off separately. The gases which rise are burned to heat the blast and boilers, and have also been used recently in gas-engines. The output of some of the recent American furnaces is very large. That of two furnaces near Cleveland, O., is 600 tons each in every 24 hours.
The reverberatory furnace is a furnace of the flame-class. The flame-chamber is arched in order that the heat may be reflected and concentrated upon the work on the hearth, and hence comes the name reverberatory. These furnaces are used in metallurgical processes, particularly in handling steel. See STEEL.
The amount of heat utilized in most furnaces is a very small part of the whole pro*
BLAST FURNACE
