FUR 
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the power of gallows and pit, or a jurisdiction 
of punishing felons, viz. me men by hanging, 
and the women by drowning. 
Furca, in antiquity, a piece of timber re- 
sembling a fork, used by the Romans as an in- 
strument of punishment, which was of three 
kinds: the first only ignominious, when a mas- 
ter, for small offenceSjlorced his servant to carry 
a lurca on his shoulders about the city. 1 he 
second was penal, when the party was led 
about the circus, or other place, with the furca 
about his neck, and'whipped all the way. 
The third was capital, when the malefactor, 
having his head fastened to the furca, was 
whipped to death. 
FURCAM, ET flagellum, the meanest 
of all servile tenures, the bondman being at 
tire lord’s disposal for life and limb. 
FURCFLE', in heraldry, a cross forked at 
the ends. 
FURIA, in zoology, a genus of insects be- 
longing to the order of vermes zoophyta. 
There is but one species, viz. the infernalis. 
This has a linear smooth body ciliated on each 
side, with reflexed feelers pressed to its body. 
In Finland, Bothnia, and the northern pro- 
vinces of Sweden, it is not unfrequently 
that people are seized with a pungent pain, 
confined to a point, in the hand or other ex- 
posed part of the body, which presently in- 
creases to a most excruciating degree and 
even sometimes prove suddenly fatal. r \ his 
disorder, caused by the insect dropping out 
of the air, and in a moment burying itself in 
the flesh, is relieved by a poultice of curds 
or cheese. 
FURLING, in the sea-language, signifies 
the wrapping up and binding any sail close to 
the yard ; which is done by hauling upon the 
clew-lines, bunt-lines, &c. which wraps the 
sail close together, and being bound last to 
the yard, the sail is furled. 
FURLONG a long measure, equal to j 
of a mile, or forty poles. It is also used, in 
some law-books, tor the eighth part ol an acre. 
FURLOUGH, in the military language, a 
licence granted by an officer to a soidier, to 
be absent for some time from bis duty. 
FURNACE, an utensil to raise and main- 
tain a vehement fire in, whether of coal or 
wood. 
In order to apply fire, to manage and to 
direct it where it is to act, furnaces are con- 
venient, and they. are the most necessary and 
indispensible instruments to chemists. I he 
materials of which they are constructed ought 
to be sufficiently proof against that degree of 
heat, which they are intended to be exposed 
to. Commonly they are built of bricks, 
made of sand and clay, or of cast-iron, or of 
iron plates, which, the better to be defended 
against the lire, are coated (in the inside) to 
the thickness of an inch with Windsor loam. 
According to Lewis, various kinds of fire- 
proof furnaces, for small experiments, may be 
sired from black-lead crucibles, 
he burning of the fuel is kept up in the 
furnace either by a natural current of air, 
which is caused by the fire itself, and such a 
furnace is called an air wind-furnace ; or it is 
done bv compressed air, conveyed to the fur- 
nace by a large bellows, as in blast-furnaces. 
Every wind-furnace consists of two essen- 
tial pads: the fire-place hfeavth, or that where 
the material destined for the fuel is placed ; 
and the ash-pit, that receives the ashes of the 
consumed fuel, admits the air through its 
F U R 
aperture (the ash-hole), and is separated irom 
the hearth by the grate. 
If the bodies to be examined are not imme- 
diately placed upon the lire, but either on 
iron bars, or in vessels to he heated by the 
fire, then a third space, the laboratory, is 
formed in the wind-furnace. It by the la- 
boratory the fire-place is thoroughly closed, 
it must be provided with some vent-holes, or 
registers, to allow access of air. 
Such wind-furnaces as are closed by a 
vaulted cover, and have either at top or on 
the side, a narrow vent-pipe, or chimney, are 
called reverberatory furnaces, cuppeiung fur- 
naces. Sometimes the fire-place is a part of 
a separate furnace, from which, however, by 
the draught of air, the flame of the fuel is 
forced over, striking upon the hearth of the 
cuppelling-furnace, which then is to be con- 
sidered as the laboratory. 
The current of air in wind-furnaces arises 
from the increased elasticity ol that portion 
of air which is contained in the upper cavity 
of the fire-place, it being there heated by the 
fire, anti naturally caused to expand. \\ hen 
this air rises by its increased elasticity, the 
denser and colder air below the grate must, 
of course, force its way to the hearth, blow 
up the lire, and thus maintain the combustion. 
It is obvious that, the air being rarer in the 
upper regions of the atmosphere, the higher 
the chimney in a close air or wind-furnace, 
tire stronger will be the draught; that is, the 
air in the upper part of the chimney being 
exceedingly rarefied by the heat, and the at 
mospheric air at the vent or upper orifice of 
the chimney being rarer than the air below, 
there will be less resi tance to the stream of 
rarefied air. The cold and dense air from 
below will therefore rush violently towards 
the ash-pit, to restore the equilibrium, and 
will penetrate through the fire, which it thus 
furnishes with a constant supply of fresh oxy- 
gen gas (the proper food of fire), and becom- 
ing rarefied in it; turn by the accession o! 
caloric, will force its way up the chimney, 
and thus a continual circulation is maintained, 
which will support almost any degree of heat 
while there, is a regular supply of fuel, it the 
chimney is of a considerable height. It is 
evident” that the size of the ash-hole should 
no: be too large, but bear a proportion to the 
height of the chimney. 
The perfection ot a wind-furnace therefore 
consists, 1, in a good current of air; 2, in 
keeping the heat together, without losing too 
great a quantity of it unused ; and, 3, in the 
facility with waich the heat may be increased 
or weakened. The heat in wind-furnaces 
is increased, partly by an additional supply of 
fuel, partly by accelerating the draught of air. 
'['he last is effected by opening the door of 
the ash-pit wider, by shutting that of the fire- 
place, by opening the registers, and lengthen- 
ing the chimney by additional vent-pipe, 
and also occasionally by applying the ac- 
tion of the bellows. "The heat again is dimi- 
nished by diminishing the quantity or celerity 
of the current of air; hence, by shutting the 
ash-hole, the registers, and vent-pipes, and 
by the proper application of these means the 
action of fire is weakened, or thoroughly sup- 
pressed. 
Blast-furnaces increase the heat upon 
the same principle, by bringing in contact 
with the fuel a fresh supply of oxygen, but 
this being effected by mechanical means, viz. 
by bellows, they are of a simpler construc- 
tion than wind-furnaces, and their ash-pit, 
hearth, and laboratory, are commonly but one 
and the same part. The blowing is most 
frequently effected by bellows, which for small 
experiments are always made of leather, and ] 
to act without interruption, should be double. 1 
At the smelting works, wooden bellows are 1 
used ; but these being single, there are always 1 
at the same time two of them employed, J 
alternately opening and shutting. The cy-| 
linder-bellows are a discovery of modern J 
times, and exceed the common by many ad- 
vantages. Water-drums, as they are called, 1 
may likewise serve for these purposes. 
When the vessels in which bodies are ex- 
posed to the action of heat are not placed in 
immediate contact with the fire in the wind- 
furnace, but receive the required degree of 
heat by another intermediate body, such ap-; 
paratus is called a bath. The "proper in- 
strument for this purpose is the sand-furnace j 
or a wind-furnace, whose upper aperture is 
shut by the sand-pot. Sand-pots are cylin- 
drical vessels, having an outwardly convex 
bottom, and made of cast or sheet-iron, 
and at times of baked clay. Glass vessels, 
however, containing bodies that are to be ex- 
posed to heat, are not placed in the pot while 
empty; but in order that they may be heated 
uniformly, this last is filled with some other 
body, into which the vessels are lodged! 
The matter most commonly employed in- 
fliis case is dry, finely sifted sand ; aiid the 
pot filled w.tb it is called a sand-bath. Of 
all baths the sand-bath is the most convenient,; 
and sufficient to apply any degree, from gen- 
tle warmth to red-heat. Crucibles placed be- 
tween coals, are also used for a sand-bath in- 
stead of sand-pots. 
It vessels are heated by means of hot waiter, 
in which they are immersed, it is called a 
water-bath, balneum mariae; but if they aid 
heated merely by the steam of boiling water! 
it is called a vapour-bath. Since water boil- 
ing in the open air is capable of receiving 
only a determinate degree of heat, it be- 
comes thereby a sure means to impart heat,] 
without danger of exceeding a certain degree.] 
Furnace, glass painters, is made of brick, 
nearly square, and about 2 | feet each way] 
ft is cut horizontally in the middle by a grate] 
which sustains the pan or shovel the glass is 
baked in. This furnace has two apertures] 
one below the grate, to put the fuel in at; 
the other above it, through which the work] 
man spies how the action ofthe colours goes on j 
Furnaces, halters, are of three kinds: a 
little one under the mould, whereon thel 
form their hats; a larger in the scouring-roomJ 
under a little copper, full of lees; and a very] 
large one under the great copper, wherein 
they dye their hats. 
FURR, in commerce, signifies the skin of 
several wild beasts, d.essed in alum with the 
hair 011 , and used as a part of dress bv 
princes, magistrates, and others. The kinds 
most in use are those ofthe ermine, sable,: 
castor, hare, rabbit, &c. 
Furrs, in heraldry, abearing which repre- 
sents the skins of certain beasts, used as well 
m the doublings of the mantles belonging to 
the coat-armours, as in the. coat-armour them- 
selves. 
FURZE, or furze-bush. See Ulex. 
FUSANUS, a genus of the polygamia 
moncecia class and order. The herin. cal. 
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