1. _Stars_ are small, round, or cubic solids, made with one of the
following compositions, and soaked in spirits. _White stars_, nitre, 16;
sulphur, 8; gunpowder, 3. Others more vivid consist of nitre, 16;
sulphur, 7; gunpowder, 4.
_Stars for golden showers_, nitre, 16; sulphur, 10; charcoal, 4;
gunpowder, 16; lamp-black, 2. Others yellower are made with nitre, 16;
sulphur, 8; charcoal, 2; lamp-black, 2; gunpowder, 8.
The _serpents_ are small fusees made with one or two playing cards;
their bore being less than half an inch. The _lardons_ are a little
larger, and have three cards; the _vetilles_ are smaller. Their
composition is, nitre, 16; charcoal, not too fine, 2; gunpowder, 4;
sulphur, 4; fine steel filings, 6.
The _petards_ are cartridges filled with gunpowder and strangled.
The _saxons_ are cartridges clayed at each end, charged with the
brilliant turning fire, and perforated with one or two holes at the
extremity of the same diameter.
The _cracker_ is a round or square box of pasteboard, filled with
granulated gunpowder, and hooped all round with twine.
_Roman candles_ are fusees which throw out very bright stars in
succession. With the composition (as under) imbued with spirits and
gum-water, small cylindric masses are made, pierced with a hole in their
centre. These bodies, when kindled and projected into the air, form the
stars. There is first put into the cartridge a charge of fine gunpowder
of the size of the star; above this charge a star is placed; then a
charge of composition for the Roman candles.
The _stars_, when less than 3/4 of an inch, consist of nitre, 16;
sulphur, 7; gunpowder, 5. When larger, of nitre, 16; sulphur, 8;
gunpowder, 8.
_Roman candles_, nitre, 16; charcoal, 6; sulphur, 3. When above 3/4 of
an inch nitre, 16; charcoal, 8; sulphur, 6.
The _girandes_, or bouquets, are those beautiful pieces which usually
conclude a fire-work exhibition; when a multitude of jets seem to
emblazon the sky in every direction, and then fall in golden showers.
This effect is produced by distributing a number of cases open at top,
each containing 140 sky-rockets, communicating with one another by
quick-match strings planted among them. The several cases communicate
with each other by _conduits_, whereby they take fire simultaneously,
and produce a volcanic display.
_The water fire-works_ are prepared like the rest; but they must be
floated either by wooden bowls, or by discs and hollow cartridges fitted
to them.
_Blue fire for lances_ may be made with nitre, 16; antimony, 8; very
fine zinc filings, 4. Chinese paste for the stars of Roman candles,
bombs, &c.:--Sulphur, 16; nitre, 4; gunpowder meal, 12; camphor, 1;
linseed oil, 1; the mixture being moistened with spirits.
The _feu grégois_ of Ruggieri, the son:--Nitre, 4; sulphur, 2; naphtha,
1. See PYROTECHNY and ROCKETS.
The red fire composition is made by mixing 40 parts of nitrate of
strontia, 13 of flowers of sulphur, 5 of chlorate of potash, and 4 of
sulphuret of antimony.
White fire is produced by igniting a mixture of 48 parts nitre; 13-1/4
sulphur; 7-1/4 sulphuret of antimony; or, 24 nitre, 7 sulphur, 2
realgar; or, 75 nitre, 24 sulphur, 1 charcoal; or, finally, 100 of
gunpowder meal, and 25 of cast-iron fine borings.
The blue fire composition is, 4 parts of gunpowder meal; 2 of nitre;
sulphur and zinc, each 3 parts.
FISH-HOOKS (_Hameçons_, Fr.; _Fischangeln_, Germ.); are constructed with
simple tools, but require great manual dexterity in the workmen. The
iron wire of which they are made should be of the best quality, smooth,
and sound. A bundle of such wire is cut in lengths, either by shears or
by laying it down upon an angular wedge of hard steel fixed horizontally
in a block or anvil, and striking off the proper lengths by the blows of
a hammer. In fashioning the _barbs_ of the hooks, the straight piece of
wire is laid down in the groove of an iron block made on purpose, and is
dexterously struck by the chisel in a slanting direction, across so much
of the wire as may be deemed necessary. A sharp-pointed little wedge is
thus formed, whose base graduates into the substance of the metal.
The end of the wire where the line is to be attached is now flattened or
screw-tapped; the other end is sharp pointed, and the proper twisted
curvature is given. The soft iron hooks are next case-hardened, to give
them the steely stiffness and elasticity, by imbedding them in animal
charcoal contained in an earthen or iron box; see CASE-HARDENING; after
which they are brightened by heating and agitating them with bran, and
finally tempered by exposure to a regulated temperature upon a hot iron
plate. Hooks for salt-water fishing are frequently tinned, to prevent
them wearing rapidly away in rust. See TIN PLATE.
FLAKE WHITE; is the name sometimes given to pure white-lead.
FLAME (_Flamme_, Fr. and Germ.); is the combustion of an explosive
mixture of an inflammable gas or vapour with air. That it is not, as
many suppose, combustion merely at the exterior surface, is proved by
plunging a fragment of burning phosphorus or sulphur into the centre of
a large flame of alcohol. Either of these bodies will continue to burn
there with its peculiar light; thus proving that oxygen is mixed with
the whole of the burning vapour. If we mix good coal gas with as much
atmospheric air as can convert all its carbon into carbonic acid, the
mixture will explode with a feeble blue light; but if we mix the same
gas with a small quantity of air, it will burn with a rich white flame.
In the latter case, the carbonaceous particles are precipitated, as Sir
H. Davy first showed, in the interior of the flame, become incandescent,
and constitute white light: for from the ignition of solid matter alone
can the prismatic rays be emitted in that concentrated union. Towards
the interior of the flame of a candle, a lamp, or a gas jet, where the
air is scanty, there is a deposition of solid charcoal, which first by
its ignition, and afterwards by its combustion, increases in a high
degree the intensity of the light. If we hold a piece of fine wire gauze
over a jet of coal gas close to the orifice, and if we then kindle the
gas, it will burn above the wire with its natural brilliancy; but if we
elevate the gauze progressively higher, so as to mix more and more air
with it before it reaches the burning point, its flame will become
fainter and less white. At a certain distance it becomes blue, like that
of the above explosive mixture. Since the combustion of all the
constituents is in this case direct and complete, the heat becomes
greatest in proportion nearly as the light is diminished. If a few
platina wires be held in that dim flame they will grow instantly white
hot, and illuminate the apartment. On reversing the order of this
experiment, by lowering progressively a flat piece of wire gauze from
the summit towards the base of a gas flame, we shall find no charcoal
deposited at its top, because plenty of air has been introduced there to
convert all the carbon of the gas into carbonic acid, and therefore the
apex is blue; but as we descend, more and more charcoal will appear upon
the meshes. At the very bottom, indeed, where the atmospheric air
impinges upon the gauze, the flame is again blue, and no charcoal can
therefore be deposited.
The fact of the increase of the brilliancy and whiteness of flame by the
development and ignition of solid matter in its bosom, illustrates many
curious phenomena. We can thus explain why olefiant gas affords the most
vivid illumination of all the gases; because, being surcharged with
charcoal, its hydrogen lets it go in the middle of the flame, as it does
in an ignited porcelain tube, whereby its solid particles first get
ignited to whiteness, and then burn away. When phosphorus is inflamed,
it always yields a pure white light, from the ignition of the solid
particles of the snowy acid thus produced.
In the blowpipe, the inner blue flame has the greatest heat, because
there the combustion of the whole fatty vapour is complete. The feeble
light of burning hydrogen, carbonic oxide, and sulphur, may, upon the
principles now expounded, be increased by simply placing in them a few
particles of oxide of zinc, slender filaments of amianthus, or fine
platina wire. Upwards of twenty years ago, I demonstrated in my public
lectures in Glasgow, that by narrowing the top of a long glass chimney
over an argand flame either from oil or coal gas, the light could be
doubled, at the same cost of material. The very tall chimneys used by
the Parisian lampists are very wasteful. I find that with a narrow
chimney of half the length of theirs, I can have as good a light, and
save 30 per cent. of the oil. Thus the light of a flame may be increased
by diminishing its heat, or the intensity of its combustion; and
conversely the heat of a flame may be increased by diminishing its
light.
FLANNEL; a plain woollen stuff of a rather open and slight fabric.
FLAX. By this term we understand the _bast_ or inner bark of the _Linum
usitatissimum,_ which is spun into yarn for weaving linen webs. This
plant blossoms in June or July, and commonly ripens its seeds in
September. As varieties, we distinguish the _spring_ flax, with short
knotty stems, whose seed capsules at the period of maturity, spring open
with a perceptible sound; and the _close_ flax, with longer smoother
stems, whose capsules give out their seeds only when threshed. The
Germans, who have bestowed much attention upon the culture of flax, call
the former _Klanglein_ or _Springlein_, and the latter _Dreschlein_.
This is the kind most commonly grown, but from the difference of
climate, soil, and culture, it affords flax of very different qualities.
The best ground for this plant is an open, somewhat friable clay,
mingled with sand and mould. The early flax is usually sown in the end
of April or beginning of May, the late, in June. The seeds ought to be
sown thick, whereby the stalks are forced to grow more slender, and the
fibres of the bast or harl are not only smoother and finer, but more
uniform in length. If the raising of seed be the principal object, the
flax must be more thinly sown, whereby it will produce stronger stalks,
but more knotty, with shorter fibres, and more productive of tow.
Whenever the flax is ripe, which is shown by the bottom of the stalk
becoming yellow, and the leaves beginning to drop off, it must be
immediately reaped by pulling it up by the roots. The seeds are still
immature, fit merely for the oil press, and not for sowing. When the
seed crop is the object, the plant must be suffered to acquire its full
maturity; in which case the fibres are less fine and soft.
The flax is carried off the field in bundles to be rippled, or stripped
of its seeds, which is done by drawing it by handfuls, through an iron
comb with teeth eight inches long, fixed upright in a horizontal beam.
When the seeds are more fully ripened, they may be separated by the
threshing mill.
The operations next performed upon the flax, will be understood by
attending to the structure of the stem. In it, two principal parts are
to be distinguished; the woody heart or boon, and the _harl_ (covered
outwardly with a fine cuticle), which encloses the former like a tube,
consisting of parallel lines. In the natural state, the fibres of the
harl are attached firmly not only to the boon, but to each other by
means of a green or yellowish substance. The rough stems of the flax
after being stripped of their seeds, lose in moisture by drying in warm
air, from 55 to 65 per cent. of their weight; but somewhat less when
they are quite ripe and woody. In this dry state, they consist in 100
parts of from 20 to 23 per cent. of _harl_, and from 80 to 77 per cent.
of boon. The latter is composed upon the average of 69 per cent. of a
peculiar woody substance, 12 per cent. of a matter soluble in water, and
19 per cent. of a body not soluble in water, but in alkaline lyes. The
_harl_ contains at a mean 58 per cent. of pure flaxen fibres, 25 parts
soluble in water (apparently extractive and albumen), and 17 parts
insoluble in water, being chiefly gluten. By treating the harl with
either cold or hot water, the latter substance is dyed brown by the
soluble matter, while the fibres retain their coherence to one another.
Alkaline lyes, and also, though less readily, soap water, dissolve the
gluten, which seems to be the cement of the textile fibres, and thus set
them free.
The cohesion of the fibres in the rough harl is so considerable that by
mechanical means, as by beating, rubbing, &c., a complete separation of
them cannot be effected, unless with great loss of time, and rupture of
the filaments. This circumstance shows the necessity of having recourse
to some chemical method of decomposing the gluten. The process employed
with this view is a species of fermentation, to which the flax stalks
are exposed; it is called _retting_, a corruption of rotting, since a
certain degree of putrefaction takes place. The German term is
_rusting_. This is the first important step in the preparation of flax.
After the retting is completed, the boon of the stalks must be removed
by the second operation called _breaking_, and other subordinate
processes. The harl freed from the woody parts contains still a
multitude of fibres, more or less coherent, or entangled, and of
variable lengths, so as to be ill adapted for spinning. These are
removed by the _heckle_, which separates the connected fibres into their
finest filaments, removes those that are too short, and disentangles the
longer ones.
I. _Of retting._--The fermentation of this process may be either
rendered rapid by steeping the flax in water, or slow by using merely
the ordinary influence of the atmospheric damp, dews, and rain. Hence
the distinction of water-retting and dew-retting. Both may also be
combined.
Prior to being retted, the flax should be sorted according to the length
and thickness of its stalks, and its state of maturity; the riper the
plant, the longer must the retting last. The due length of the process
is a point too little studied.
_Water-retting._--When flax stalks are macerated in water, at a
temperature not too low, fermentation soon begins, evinced in the dingy
infusion, by disengagement of carbonic acid gas, and the production of
vinegar. If the flax be taken out at the end of a few days, dried, and
rubbed, the textile filaments are found to be easily separable from each
other. By longer continuance of the steep, the water ceases to be acid,
it becomes to a certain degree alkaline, from the production of ammonia,
diffuses a fetid odour, from the disengagement of sulphuretted hydrogen
gas, along with the carbonic acid; the acetous fermentation being in
fact now changed into the putrid. The filaments become yellowish brown,
afterwards dark brown and lose much of their tenacity, if the process be
carried further.
When the operation is conducted with discernment, the water-retting may
be completed by the acetous fermentation alone, as the putrefaction
should never be suffered to proceed to any length; because when
over-retted, flax is partially rotten, gets a bad colour, and yields a
large proportion of tow.
For water-retting, the flax must be bound up in sheaves, placed in
layers over each other in the water, or sometimes upright, with the
roots undermost. Straw may be put below to keep it from touching the
ground, and boards may be laid upon the top, with weights to hold it
immersed about a foot beneath the surface, especially when the
fermentative gases make it buoyant. As soon as it sinks at the end of
the fermentation, it must be inspected at least twice a day, and samples
must be taken out to see that no over-retting ensues. A single day too
long often injures the flax not a little. We may judge that the retting
is sufficient when the harl separates easily from the boon by the
fingers, when the boon breaks across without bending, and when several
stalks knotted together sink to the bottom upon being thrown into the
water. For this completion, a shorter or longer time is required
according to the quality of the flax, the temperature, &c., so that the
term may vary from five to fourteen days. It may be done either in
running or in stagnant water. For the latter purpose, tanks five feet
deep are dug in the ground. In stagnant water, the process is sooner
finished, but it is more hazardous, and gives a deeper stain to the
fibres, than in a stream, which carries off much of the colour. The best
place for steeping flax is a pond with springs of water at its bottom;
or a tank into which a rivulet of water can be occasionally admitted,
while the foul water is let off. For every fresh quantity of flax, the
pond should be emptied, and supplied with clear water. Water impregnated
with iron, stains flax a permanent colour, and should therefore never be
used. After retting, the flax should be taken out without delay, rinsed
in clean water, and exposed in an airy situation to dry by the sun.
Rough rippled flax stalks, well seasoned before being retted, and dried
afterwards, show a loss of weight, amounting to 20 or 30 per cent.,
affecting both the boon and the harl. This loss is greater the finer the
stems, and the longer the retting. The harl contains, beside the textile
filaments, a certain portion of a glutinous cement; but nothing soluble
in water. The destruction of the gluten cannot be pushed to the last
point by steeping, without doing an essential injury to the filaments.
_Dew-retting._--The fetid and noxious exhalations which the
water-retting diffuses over an extensive district of country, and the
danger of over-retting in that way, especially with stagnant water, are
far from recommending that process to general adoption. Dew-retting
accomplishes the same purpose, by the agency of the air, dews, and rain,
in a much more convenient, though far slower manner. The flax, with this
view, should be spread out thin upon meadow or grass lands, but never
upon the bare ground, and turned over, from time to time, till the
stems, on being rubbed between the fingers, show that the harl and the
boon are ready to part. The duration of dew-retting is, of course, very
various, from 2 to 6, or 8 weeks, as it depends upon the state of the
weather; a moist air being favourable, and dry sunshine the reverse. The
loss of weight by dew-retting is somewhat less than by water-retting;
and the textile fibres are of a brighter colour, softer and more
delicate to the touch.
_Mixed retting._--This may be fairly regarded as the preferable plan,
the retting being begun in the water, and finished in the air. The flax
should be taken out of the steep whenever the acetous fermentation is
complete, before the putrid begins, and exposed, for 2 or 3 weeks, on
the grass.
II. _The breaking_ is performed by an instrument called a brake. In
order to give the wood or boon such a degree of brittleness as to make
it part readily from the harl, whereby the execution of this process is
rendered easy, the flax should be well dried in the sun, or what is more
suitable to the late period of the year, in a stove. Such is often
attached to the bakers’ ovens in Germany, and other flax-growing
countries. The drying temperature should never exceed 120° F., for a
higher heat makes it brittle, easy to tear, and apt to run into tow.
Before subjecting the flax to the brake, the stems should be equalized
and laid parallel by the hand, and the entangled portions should be
straightened with a coarse heckle. The brake has one general
construction, and consists of two principal parts, the frame or case,
and the sword or beater. In the simplest brakes, the frame _e_, _fig._
412., is a piece of wood cleft lengthwise in the middle, supported by
the legs _a_ and _c_. The sword _f_, also of hard wood, is formed with
an edge beneath, and turns round the centre of motion at _q_, when
seized by the handle _h_, and moved up and down. As it descends, the
sword enters the cleft of the frame, and breaks the flax stalks laid
transversely upon it, scattering the boon in fragments.
[Illustration: 412 413 414]
But those hand brakes are more convenient which are provided with a
double cleft, or triple row of oblong teeth; with a double sword. This
construction will be understood by inspecting _figs._ 412, 413, 414.
_Fig._ 412. is the section of that side at which the operative sits;
_fig._ 413. is a section in the line A, B, of _fig._ 412; and _fig._
414., the ground plan. The whole machine is made of hard wood, commonly
red beech. Two planks, _a_ and _c_, form the legs of the implement. _a_
is mortised in a heavy block, to give the brake a solid bearing; two
stretchers _d_, bind _a_ and _c_, firmly together. The frame _e_
consists of three thin boards, which are placed edgewise, and have their
ends secured in _a_ and _c_. The sword _f_ is a piece of wood, so
chamfered from _i_ to _k_, that it appears forklike, and embraces the
middle piece of the frame; its centre of motion is the wooden pin _q_;
in front is the handle _h_, which the operative seizes with the right
hand. Both the lathes of the frame, and those of the sword are
sharpened, from _l_ to the front end, as is best shown in _fig._ 413.;
but the edges must not be too sharp, for fear of injuring the flax; and,
for the same reason, the sword should not sink too far between the
lathes of the frame. Such hand-brakes are laborious in use, and often
tear the harl into tow. The operative, usually a female, in working the
brake, seizes with her left hand a bundle of flax, lays it transversely
across the frame, and strikes it smartly with repeated blows of the
sword, pushing forwards continually new portions of the flax into the
machine. She begins with the roots, turns next round the tips, then goes
on through the length of the stalks. Flax is frequently exposed twice to
the brake, with a stove drying between the two applications.
[Illustration: 415 416 417]
The brake machines afford a far preferable means of cleaning flax than
the above hand tools. The essential part of such a machine, consists in
several deeply fluted rollers of wood or iron, whose teeth work into
each other, and while they stretch out the flaxen stalks betwixt them,
they break the wood or boon, without doing that violence to the harl
which hand mechanisms are apt to do. The following may be regarded as
one of the best constructions hitherto contrived for breaking flax.
_Fig._ 415. is a view of the right side of this machine. _Fig._ 416.,
the view from behind, where the broken flax issues from between the
rollers. The frame is formed by the two side pillars or walls _a_, _a_,
which are mortised into the bottom _b_, _b_; and are firmly fixed to it
by braces. Two transverse rods _d_, _d_, secure the base, two others _d´
d´´_, the sides. In each of these a lateral arm _e_, is mortised in an
oblique direction; a cross bar _f_, unites both arms. _Fig._ 417. shows
the inside of the left side of the frame, with the subsidiary parts. The
three rollers _g_, _i_, _k_, may be made of red beech, with iron
gudgeons, and fluted in their length, each of the flutes being 5/12 of
an inch broad, and 4/12ths deep. The large roller _g_, bears upon the
right side, a handle _h_, which on being turned, sets the whole train in
motion. The side partitions _a_, _a_, are furnished with brasses in
whose round holes _l_, _g_, _fig._ 417., the gudgeons _g_ work. For the
extremities of the two smaller rollers, there are at _a_ and _e_, slots
in brasses, as may be seen in _fig._ 415. Within the partition _a_,
there are movable brasses _l_, for the pivots of _i_ and _k_, shewn in
_fig._ 417. Each brass slides in a groove, between two ledges. A strong
cord made fast at _m_ to the partition _a_, runs over the brass of _i_,
next over that of _k_, then descends perpendicularly, and passes over
the cross bar _n_, _fig._ 415. and 416. This construction being repeated
at both ends of the rollers, the rod _n_, binds both cords. Against the
cross bar _d´_ of the frame, a lever _o_ is sustained, which lies upon
the rod _n_, and carries a weight _p_. The farther or nearer this weight
hangs towards the end of the lever, it stretches the cord more or less,
and presses by means of the brasses _l_, the rollers _i_, _k_, towards
the main roller _g_. A table _q_, serves for spreading out the flax to
be broken, and a second one _r_, for the reception of the stalks at
their issuing from between the rollers. Both tables hang by means of
iron hooks to rings of the frame _s_, _t_, _fig._ 415. and 417., and are
supported by the movable legs _u_, _u_, _u_, _fig._ 415. and 416. In
using the machine the operative lays an evenly spread handful of flax
upon the table _q_, introduces their root ends with his left hand
between the rollers _g_ and _i_, and turns round the handle _h_, with
the right. The stems are first broken betwixt _g_ and _i_, then between
_g_ and _k_, and come out upon the table _r_. The handle is moved
alternately forwards and backwards, in order that the flax may be rolled
alternately in the same directions, and be more perfectly broken. The
boon falls down in very small pieces, and the harl remains expanded in
parallel bands. This should be drawn over the points of a heckle, then
laid for a couple of days in a cellar to absorb some moisture, and
afterwards worked once more through the machine, whereby the flax
acquires a peculiar softness.