Linen manufactures exported,
including flax yarn, declared
value _£_3,208,139 _£_3,645,097 _£_2,613,293
FLINT. (_Pierre à fusil_, Fr; _Feuerstein_, Germ.) The fracture of this
fossil is perfectly conchoidal, sometimes glossy, and sometimes dull on
the surface. It is very hard, but breaks easily, and affords very
sharp-edged splintery fragments; whence it is a stone which strikes most
copious sparks with steel. It is feebly translucid, has so fine and
homogeneous a texture as to bear polishing, but possesses little lustre.
Its colours are very various, but never vivid. The blackish-brown flint
is that usually found in the white chalk. It is nearly black and opaque,
loses its colour in the fire, and becomes grayish-white, and perfectly
opaque. Flints occur almost always in nodules or tubercular concretions
of various and very irregular forms. These nodules, distributed in
strata among the chalk, alongside of one another and almost in contact,
form extensive beds; interrupted, indeed, by a multitude of void spaces,
so as to present, if freed from the earthy matter in which they are
imbedded, a species of network with meshes, very irregular both in form
and dimension.
The nodules of silex, especially those found in the chalk, are not
always homogeneous and solid. Sometimes there is remarked an organic
form towards their centre, as a madrepore or a shell, which seems to
have served as their nucleus; occasionally the centre is hollow, and its
sides are studded over with crystals of quartz, carbonate of iron,
pyrites, concretionary silex or calcedony, filled with pulverulent
silica nearly pure, or silex mixed with sulphur; a very singular
circumstance.
Flints are observed to be generally humid when broken immediately after
being dug out of the ground; a property which disappears after a short
exposure to the air. When dried they become more brittle and more
splintery, and sometimes their surfaces get covered at old fractures
with a thin film or crust of opaque silex.
Flints calcined and ground to a powder enter into the composition of all
sorts of fine pottery ware.
The next important application of this siliceous substance is in the
formation of gun-flints, for which purpose it must be cut in a peculiar
manner. The following characters distinguish good flint nodules from
such as are less fit for being manufactured. The best are somewhat
convex, approaching to globular; those which are very irregular,
knobbed, branched and tuberose, are generally full of imperfections.
Good nodules seldom weigh more than 20 pounds; when less than 2, they
are not worth the working. They should have a greasy lustre, and be
particularly smooth and fine grained. The colour may vary from
honey-yellow to blackish-brown, but it should be uniform throughout the
lump, and the translucency should be so great as to render letters
legible through a slice about one-fiftieth of an inch thick, laid down
upon the paper. The fracture should be perfectly smooth, uniform, and
slightly conchoidal; the last property being essential to the cutting
out of perfect gun-flints.
Four tools are employed by the gun-flint makers.
First, a hammer or mace of iron with a square head, from 1 to 2 pounds
weight, with a handle 7 or 8 inches long. This tool is not made of
steel, because so hard a metal would render the strokes too harsh, or
dry as the workmen say, and would shatter the nodules irregularly,
instead of cutting them with a clean conchoidal fracture.
Second, a hammer with 2 points, made of good steel well hardened, and
weighing from 10 to 16 ounces, with a handle 7 inches long passing
through it in such a way that the points of the hammer are nearer the
hand of the workman than the centre of gravity of the mass.
Third, the disc hammer or roller, a small solid wheel, or flat segment
of a cylinder, parallel to its base, only two inches and a third in
diameter, and not more than 12 ounces in weight. It is formed of steel
not hardened, and is fixed upon a handle 6 inches long, which passes
through a square hole in its centre.
Fourth, a chisel tapering and bevelled at both extremities, 7 or 8
inches long, and 2 inches broad, made of steel not hardened; this is set
on a block of wood, which serves also for a bench to the workmen. To
these 4 tools a file must be added, for the purpose of restoring the
edge of the chisel from time to time.
After selecting a good mass of flint, the workman executes the following
four operations on it.
1. _He breaks the block._ Being seated upon the ground, he places the
nodule of flint on his left thigh, and applies slight strokes with the
square hammer to divide it into smaller pieces of about a pound and a
half each, with broad surfaces and almost even fractures. The blows
should be moderate, lest the lump crack and split in the wrong
direction.
2. _He cleaves or chips the flint._ The principal point is to split the
flint well, or to chip off scales of the length, thickness, and shape
adapted for the subsequent formation of gun flints. Here the greatest
dexterity and steadiness of manipulation are necessary; but the fracture
of the flint is not restricted to any particular direction, for it may
be chipped in all parts with equal facility.
The workman holds the lump of flint in his left hand, and strikes with
the pointed hammer upon the edges of the great planes produced by the
first breaking, whereby the white coating of the flint is removed in
small scales, and the interior body of the flint is laid bare; after
which he continues to detach similar scaly portions from the clean mass.
These scaly portions are nearly an inch and a half broad, two inches and
a half long, and about one-sixth of an inch thick in the middle. They
are slightly convex below, and consequently leave in the part of the
lump from which they were separated a space slightly concave,
longitudinally bordered by two somewhat projecting straight lines or
ridges. The ridges produced by the separation of the first scales must
naturally constitute nearly the middle of the subsequent pieces; and
such scales alone as have their ridges thus placed in the middle are fit
to be made into gun-flints. In this manner the workman continues to
split or chip the mass of flint in various directions, until the defects
usually found in the interior render it impossible to make the requisite
fractures, or until the piece is too-much reduced to sustain the smart
blows by which the flint is divided.
3. _He fashions the gun-flints._ Five different parts may be
distinguished in a gun-flint. 1. The sloping facet or bevel part, which
is impelled against the hammer of the lock. Its thickness should be from
two to three twelfths of an inch; for if it were thicker it would be too
liable to break; and if more obtuse, the scintillations would be less
vivid. 2. The sides, or lateral edges, which are always somewhat
irregular. 3. The back or thick part opposite the tapering edge. 4. The
under surface, which is smooth and rather concave. And 5. The upper
face, which has a small square plane between the tapering edge and the
back, for entering into the upper claw of the cock.
In order to fashion the flint, those scales are selected which have at
least one of the above mentioned longitudinal ridges; the workman fixes
on one of the two tapering borders to form the striking edge, after
which the two sides of the stone that are to form the lateral edges, as
well as the part that is to form the back, are successively placed on
the edge of the chisel in such a manner that the convex surface of the
flint, which rests on the forefinger of the left hand, is turned towards
that tool. Then with the disc hammer he applies some slight strokes to
the flint just opposite the edge of the chisel underneath, and thereby
breaks it exactly along the edge of the chisel.
4. The finishing operation is the _trimming_, or the process of giving
the flint a smooth and equal edge; this is done by turning up the stone
and placing the edge of its tapering end upon the chisel, in which
position it is completed by 5 or 6 slight strokes of the disc hammer.
The whole operation of making a gun-flint, which I have used so many
words to describe, is performed in less than one minute. A good workman
is able to manufacture 1000 good chips or scales in a day (if the
flint-balls be of good quality), or 500 gun-flints. Hence, in the space
of 3 days, he can easily cleave and finish 1000 gun-flints without any
assistance.
A great quantity of refuse matter is left, for scarcely more than half
the scales are good, and nearly half the mass in the best flints is
incapable of being chipped out; so that it seldom happens that the
largest nodules furnish more than 50 gun-flints.
Flints form excellent building materials; because they give a firm hold
to the mortar by their irregularly rough surfaces, and resist, by their
nature, every vicissitude of weather. The counties of Kent, Essex,
Suffolk, and Norfolk contain many substantial specimens of
flint-masonry.
FLOSS, of the puddling furnace, is the fluid glass floating upon the
iron produced by the vitrification of the oxides and earths which are
present.
FLOSS-SILK (_Filoselle_, _Bourre de soie_, or _fleuret_, Fr.); is the
name given to the portions of ravelled silk broken off in the filature
of the cocoons, which is carded like cotton or wool, and spun into a
soft coarse yarn or thread, for making bands, shawls, socks, and other
common silk fabrics. The floss or fleuret, as first obtained, must be
steeped in water, and then subjected to pressure, in order to extract
the gummy matter, which renders it too harsh and short for the spinning
wheel. After being dried it is made still more pliant by working a
little oil into it with the hands. It is now ready to be submitted to
the carding engine. See COTTON MANUFACTURE. It is spun upon the flax
wheel.
The female peasants of Lombardy generally wear clothes of homespun floss
silk. Of late years, by improved processes, pretty fine fabrics of this
material have been produced both in England and France. M. Ajac, of
Lyons, presented at one of the French national exhibitions of the
objects of industry, a great variety of scarfs and square shawls, of
_bourre de sole_, closely resembling those of _cachemere_.
FLOUR; the finely ground meal of wheat, and of any other corns or
_cerealia_. See BREAD.
FLOUR OF WHEAT, _Adulterations of_, _to detect_.
The first method is by specific gravity. If potato flour be added, which
is frequently done in France, since a vessel which contains one pound of
wheat flour will contain one pound and a half of the fecula, the
proportion of this adulteration may be easily estimated. If gypsum or
ground bones be mixed with the flour, they will not only increase its
density still more; but they will remain after burning away the meal.
The second method is by ascertaining the quantity of gluten which the
suspected sample will afford, by the process prescribed under the
article BREAD. The two following chemical criteria may also be employed.
1st. Nitric acid has the property of colouring wheat flour of a fine
orange yellow, whereas it affects the colour neither of fecula nor
starch.
2nd. Pure muriatic acid colours good wheat flour of a deep violet, but
dissolves fecula or starch, and forms with it a light, colourless,
viscous fluid, decomposable by alkalis. It may also be observed, that as
fecula absorbs less water than flour, this affords a ready means of
detection.
The adulteration with bean or pea flour may be detected by pouring
boiling water upon it, which developes the peculiar smell of these two
substances.
FLOWERS (_Fleurs_, Fr.; _Blumen_, Germ.) of benzoin, of sulphur, of
zinc, &c., is the appellation given by the older chemists to such
substances as were obtained in a pulverulent or rather minutely
crystalline form by the process of sublimation.
FLOWERS, ARTIFICIAL, MANUFACTURE OF. The art of representing by flowers,
leaves, plants, &c., vegetable nature in her ornamental productions,
constitutes the business of the artificial florist. The Italians appear
to have been the first people in Europe who excelled in the art of
making artificial flowers; but of late years the French have been most
ingenious in this branch of industry.
Ribbons folded in different forms and of different colours were
originally employed for imitating flowers, by being attached to wire
stems. This imitation soon gave way to that by feathers, which are more
delicate in texture, and more capable of assuming a variety of
flower-like figures. But a great difficulty was encountered in dyeing
them with due vivacity. The savages of South America manufacture perfect
feather flowers, derived from the brilliant plumage of their birds,
which closely resemble the products of vegetation. The blossoms and
leaves are admirable, while the colours never fade.
The Italians employ frequently the cocoons of the silkworm for this
purpose; these take a brilliant dye, preserve their colour, and possess
a transparent velvety appearance, suitable for petals. Of late years,
the French have adopted the finest cambric for making petals, and the
taffeta of Florence for the leaves. M. de Bernardière employs whalebone
in very thin leaves for artificial flowers; and by bleaching and dyeing
them of various hues, he has succeeded in making his imitations of
nature to be very remarkable.