OF PARTICULAR COMPOSITIONS.
_Sec. I. Of Fire-Jets, or Fire-Spouts._
Fire-jets are produced by certain compositions, which are employed in
cases, and are charged solid. They are formed and used according to
taste or fancy.
The jets are made with a caliber of from one-third of an inch, to one
inch and one-third, in interior diameter. They are seven or eight
exterior diameters in length, and are charged in the usual manner
with the composition, hereafter mentioned, driving each charge with
twenty blows with a small mallet. The first charge must be the common
fire composition.
Some of the compositions in the following table have already been
mentioned, when treating of certain fire-works; but we deem it of
importance to notice them in a connected manner, so that we may have
the formulæ in one view.
Fire-jets, it must be remembered, are calculated as well for turning,
as for fixed pieces.
_Common Fire for calibers of one-third of an inch._
Meal-powder, 16 oz.
Charcoal, 3 --
_Common Fire for calibers of five-twelfths to half an inch._
Meal-powder, 16 oz.
Charcoal, 3 -- 4 dr.
_Common fire for calibers above half an inch._
Meal-powder, 16 oz.
Charcoal, 4 --
_Brilliant fire for ordinary calibers._
Meal-powder, 16 oz.
Filings of iron, 4 --
_Another, more beautiful._
Meal powder, 16 oz.
Filings of steel, 4 --
_Another, more brilliant, for any caliber._
Meal powder, 18 oz.
Saltpetre, 2 --
Filings of steel, 5 --
_Another, very brilliant, for two-thirds of an inch caliber, and
above._
Meal powder, 16 oz.
Saltpetre, 1 --
Sulphur, 1 --
Filings of steel, 7 --
_Brilliant fire, more clear, for any caliber._
Meal powder, 16 oz.
Filings of needles, or of needle steel, 3 --
_Silver-rain for calibers above two-thirds of an inch._
Meal powder, 16 oz.
Saltpetre, 1 --
Sulphur, 1 --
Filings of steel, fine, 4 -- 4 dr.
_Grand jessamine, for any caliber._
Meal powder, 16 oz.
Saltpetre 1 --
Sulphur, 1 --
Filings of spring steel, 6 --
_Small jessamine, idem._
Meal powder, 16 oz.
Saltpetre, 1 --
Sulphur, 1 --
Filings of steel, the best, 5 --
_White fire, idem._
Meal powder, 16 oz.
Saltpetre, 8 --
Sulphur, 2 --
_White fire, idem._
Meal powder, 16 oz.
Sulphur, 3 --
_Blue fire, for parasols and cascades._
Meal powder, 8 oz.
Saltpetre, 4 --
Sulphur, 6 --
Zinc, 6 --
_Another blue fire, for calibers of half an inch, and upwards._
Saltpetre, 8 oz.
Meal powder, 4 --
Sulphur, 4 --
Zinc, 17 --
The cases charged with this composition are only employed for
furnishing the centre of some pieces, the movement of which depends
on other cases; for these, having no force, would not move the piece.
_Blue Fire, for any caliber._
Meal powder, 16 oz.
Saltpetre, 2 --
Sulphur, 8 --
_Radiant Fire, idem._
Meal powder, 16 oz.
Filings of pins, (_d'epingles_) 3 --
_Green Fire, idem._
Meal powder, 16 oz.
Filings of copper, 3 -- 2 dr.
_Aurora Fire, idem._
Meal powder, 16 oz.
Gold powder, (_Poudre d'or_) 3 --
_For Italian roses or fixed stars._
Meal powder, 2 oz.
Saltpetre, 4 --
Sulphur, 1 --
_Another, for the same._
Meal-powder, 12 oz.
Saltpetre, 16 --
Sulphur, 10 --
Antimony, 1 --
The jets of fire, which are various according to the composition
employed, may appear under several forms, sometimes in one and
sometimes in another; and hence they may put on an asteroid
appearance, or that of a fountain, or water spout, or the form of
rain. The effect, however, is very elegant; and, in conjunction
with other species of fire-works, cannot fail to change the general
appearance, by modifying the whole, or rendering it more various.
These compositions are generally used in the manner before mentioned,
in cases of different sizes; but they may, under particular
circumstances, be employed otherwise. In fact, the _forms_ which may
be given to the flame of gunpowder, or the substances which compose
it, either by increasing or retarding its combustion, or changing the
appearance of the flame, and giving it the form of jets, stars, rain,
&c. are so numerous, that it furnishes alone an important branch of
Pyrotechny. These effects will be detailed, when we treat of the
formation of compound works.
_Sec. II. Of Priming and Whitening Cases, and Remarks concerning
Spunk and Touch Paper._
When the cases are charged, we pierce them with a small awl, or make
a hole with a gimblet in the end, if it should be stopped with clay,
or _probe_ them with a drill, as fire-workers call it, in the hole
which had been filled, in which we put some more of the composition.
This precaution is considered necessary, in order that the earth
should not cover internally the hole of the piercer. A piece of match
is then introduced, which extends on the outside, and is secured
there with a plug of wood.
Brown paper, made either of linen or cotton, but not of woollen
cloth, when soaked in a concentrated solution of saltpetre, is, we
have said, rendered very combustible, and will convey fire for small
works with much facility. It is this paper, called touch, or more
properly match, paper, that is used for capping, &c. Paper of this
kind may sometimes be used, as for _crackers_, _serpents_, &c. Cotton
quick-match, however, is used more generally; and, for large works,
when employed as a leader, it is usually confined in a proper tube,
the better to preserve it entire, and to keep it dry. Spunk, made by
soaking certain species of fungus in a solution of saltpetre, takes
fire very readily by the least spark, and, therefore, is used for
collecting and preserving the fire from flint and steel. This spunk,
when well made, and particularly of the proper kind of fungus, may
be cut into slips, and employed advantageously in some fire-works.
In all cases, however, the object is the same, to communicate fire
with facility to the powder, or composition; and this object may be
attained by all those methods, which we have had occasion frequently
to mention. See _Pyrotechnical Sponge_.
To _whiten_ cases is an operation, which merely consists in covering
them with paper, and is performed in the following manner. We procure
as many half-sheets of paper as we have cases, and put them on a
table one upon another. We paste the paper, and roll each case in one
of these sheets, which is named the covering. The paper is cut in
such a manner, that it passes over the end of each case an inch and
a half. There is no particular use in this covering, the case being
made sufficiently strong without it; it makes, however, a handsome
finish. In the Chinese fire-works, their cases are covered with
different coloured papers, and frequently ornamented with gilding. In
all that I have seen, with some of which I have made experiments, the
match of communication is nothing more than twisted match-paper. The
figures are made of paper, painted, and ornamented in the same way;
some resembling animals, &c. but on a small scale. The leaders are
fixed in the usual manner, and the works are fired in the same way.
Tourbillons, serpents, and crackers are chiefly the kind which we
have seen.
_Sec. III. Of Chinese Fire._
The composition for producing this fire, as it is peculiar, and
therefore distinct from all others, was invented by the Chinese, and
hence bears that name. The substance, which produces the peculiar
effect is cast or crude iron. See _Iron_.
It was the brilliant light, produced when iron filings are thrown
into the fire, that gave rise to an improvement in the fire of
rockets, rendering it much more beautiful, than when gunpowder, or
the substances of which it is composed, are alone employed. The
Chinese have long been in possession of a method of rendering fire
brilliant, and variegated in its colours. Cast-iron, reduced to a
powder more or less fine, is called iron-sand, because it answers to
the name given to it by the Chinese. They use old iron pots, which
they pulverize, till the grains are not larger than radish seed; and
these they separate into sizes or numbers, for particular purposes.
It should be observed, that rockets, into the composition of which,
iron-filings and iron-sand enter, cannot be long preserved, owing to
the change which the iron undergoes in consequence of moisture.
It may be proper to introduce here two tables, which exhibit the
proportions of the different ingredients for rockets of this kind
from 12 to 33 lbs.
_For Red Chinese Fire._
-----------+------------+----------+-----------+------------------
Calibers. | Saltpetre. | Sulphur. | Charcoal. | Pulv. cast iron.
| | | | No. 1.
-----------+------------+----------+-----------+------------------
lbs. | lbs. | oz. | oz. | oz. dr.
12 to 15 | 1 | 3 | 4 | 7 0
18 -- 21 | 1 | 3 | 5 | 7 8
24 -- 36 | 1 | 4 | 6 | 8 0
-----------+------------+----------+-----------+------------------
_For White Chinese Fire._
-----------+------------+--------------+-----------+-----------------
Calibers. | Saltpetre. | Meal-powder. | Charcoal. | Pulv. cast iron.
| | | | No. 2.
-----------+------------+--------------+-----------+-----------------
lbs. | lbs. | oz. | oz. dr. | oz. dr.
12 to 15 | 1 | 12 | 7 8 | 11 0
18 -- 21 | 1 | 11 | 8 0 | 11 8
24 -- 36 | 1 | 11 | 8 8 | 12 0
-----------+------------+--------------+-----------+-----------------
These substances are incorporated together in the manner already
stated.
The cast-iron, we observed, is reduced to a fine powder, or rather
_sand_, as the French fire-workers call it, and is then passed
through a sieve. For the method of reducing it to powder, consult
the article on _Iron_. That the brilliancy of the fire is owing
to the iron in its crude state, without being converted into soft
or malleable iron, a process which carries off a large quantity
of carbon, oxygen, &c. and increases its specific gravity,--is
very evident from the effect produced. Wrought iron will occasion
scintillations, somewhat of the same appearance, and steel, also,
in greater abundance; and hence both are employed in sundry
compositions. But the particular character, beauty, and brilliancy
of Chinese fire must be attributed, first to the iron, and secondly
to its peculiar state of combination with carbon and oxygen; for, we
have said, that malleable iron, (which is deprived in a great measure
of these substances in the operation required for its preparation),
produces an effect far inferior to cast iron. This difference
then can only arise from the quality, character, composition, or
properties of these two kinds of iron. Steel, on the contrary, having
a more vivid effect than wrought iron, owes its properties to
another state of combination of the iron and carbon.
Hence we account for the difference in the appearance of the flame,
and consequently the effect, in the different mixtures of crude iron,
malleable iron, and steel. We have already remarked, in treating
of iron, and in explaining the action of bodies in the process of
combustion, in the section on the theory of fire-works, that the
effect of some substances was to produce sparks, stars, &c. In the
present instance, namely, the effect of the composition of the
Chinese fire by combustion, the iron is first ignited by the powerful
heat created by the combustion of the powder, nitre, charcoal, and
sulphur, and in this state, is thrown out with violence, and is
itself consumed. The combustion of iron is nothing more than its
oxidizement, during which a brilliant fire, which characterizes so
pre-eminently the Chinese fire, is produced. This oxidizement of the
metal, in proportion as it is more rapid, necessarily gives rise
to the phenomena of combustion, which, in this, and the generality
of instances, presupposes a combination with oxygen. The fire is,
therefore, more brilliant, as the combustion is more rapid, and
the metal may be oxidized in a greater or lesser degree, but not
to a maximum. From the effect taking place in the air, as it does
not ensue, or is not seen, in the case, it follows, that the iron
receives for the support of its combustion the oxygen of the air.
We have said, that the substances which compose cast-iron, are iron,
carbon, and oxygen, in a peculiar state of combination. We may also
conclude, therefore, that, as carbon, by combustion in oxygen gas,
or in atmospheric air, which contains about twenty-two per cent.
produces carbonic acid, the carbon of the iron during its combustion,
is changed, by its union with oxygen, into this acid. The products,
then, are oxide of iron, and carbonic acid, the latter existing in
the gaseous state. With respect to the other products of combustion,
arising from the gunpowder, saltpetre, sulphur, and charcoal, we have
before noticed them. See _Gunpowder_, and the _General Theory of
Fire-Works_.
We may remark, at the same time, that the intense heat, produced as
well by the combustion of the gunpowder, as by the combustion of
charcoal and sulphur, in contact with the nitrate of potassa, brings
the metal almost to a state of fusion; which, being thrown off in
this state, and considerably divided, is acted upon by the oxygen on
all sides, causing the effect to be uniform and general.
The quantity of iron, it will be seen, which enters into the
different compositions, is various, according to the particular
purpose to which the composition is applied. The _effect_, therefore,
may be varied, as we employ more or less of the iron; and the
state of ignition may be affected, as the proportions of nitre and
charcoal are increased or diminished. These facts are obvious, by
referring to the respective formulæ, and the application of the
several compositions. It is, besides, no less true, that as much
care is required in selecting pure materials for every kind of
artificial fire, as scrupulous accuracy, in following the proportions
prescribed. Nor is this all; the mixture must be intimately made, or
the effect would be doubtful and uncertain.
There is a particular manner required for preparing the composition
of Chinese fire. All the substances must be passed three times
through a sieve, except the sulphur, and the pulverized cast-iron.
These are mixed by themselves, and afterwards with the other
substances. They are turned over frequently with the hand. Cases are
filled with it in the same manner as other compositions.
In order to make the mixture of the sulphur with the iron more
intimate, the latter may be wetted occasionally with spirit of wine,
which should contain no water, as water would tend to rust the
metal, and injure its effect. The sulphur would then mix with more
freedom, and the composition be more perfect. The spirit of wine,
acting merely as a vehicle, afterwards evaporates; and, as it has no
chemical action on either the sulphur or the metal, they would remain
unaltered.
By proceeding in this manner; namely, first mixing the other
substances by themselves, and afterwards the iron and sulphur, and
then the whole, we form an intimate mixture throughout.
The composition, prepared in this way, makes the fire more brilliant;
giving it a greater lustre than by proceeding in a contrary manner.
We are informed, that spontaneous combustion has frequently taken
place, by suffering the iron and alcohol, or spirit of wine, to
remain in contact; and, although this appears an anomaly, which we
will not attempt to explain, yet that it is a fact, and that it has
occurred at Paris, we have the authority of M. Morel.
When the cast-iron is reduced to powder, or _sand_, it is divided
into several sorts, which are proportioned to the caliber employed.
These sorts are marked or numbered, and are used as follows: For
calibers under 7/12ths of an inch in diameter, No. 1; for those of
7/12ths to 10/12ths, No. 2; and for larger calibers, No. 3.
In charging with the composition, care must be taken to turn it
over repeatedly at every other ladle full; because the iron, which
is the heaviest substance, is liable to fall to the bottom. If the
composition be not equally diffused, the fire would be irregular, and
go out by puffs. This is a defect which ought to be guarded against.
The mixture of the composition for _Jessamine_ is made in the same
manner.
Chinese fire, in cases, is commonly employed in garnishing, as it is
called, the circumference of a decoration, or in forming pyramids,
galleries, yew trees, cascades, palm trees, or in short, in producing
a variety of figures, according to taste and fancy. They are often
employed in turning pieces for their last fire, in consequence of the
brilliancy of their effect.
We are told, that nothing is more elegant than Chinese fire; and that
it forms, in its descent, flowers of variegated beauty, which, being
scattered about by the rotation of the piece, resemble the _hydraulic
girandole_ in the rays of the sun.
Chinese fire, however, has little force; and hence, when it is used,
it is accompanied with other fire, as two or more jets of white fire.
The latter is only employed, when the Chinese fire is to be exhibited
on wheels, or turning pieces. When it is on fixed pieces, there is no
occasion for them. Cases of Chinese fire, when burnt alone, will not
turn a wheel.
As the effect of Chinese fire on wheels depends greatly on the
motion of the wheel, its velocity should therefore be accelerated;
which, although the duration of its effect would be shorter and more
brilliant, may be produced by employing several cases of white fire,
and communicating their fire one to the other by leaders in the usual
manner.
There is no doubt, that the accelerated motion of the wheel causes
the composition to burn more rapidly, in the same way as a bellows
excites the heat of a blast-furnace; and, therefore, the increased
brilliancy of the fire may be attributed to the greater rapidity of
the combustion, which necessarily produces, in a shorter time, the
oxidizement of the iron, and, at the same time, the combustion of the
other substances.
With respect to the comparative force of compositions, or that power
by which cases, as rockets, &c. ascend, or which gives motion to
vertical and horizontal wheels, we may observe generally, that these
effects depend on the compositions employed; and that the _recoil_,
in such instances, is proportionate to the impelling power; for the
resistance with which the fire meets from the air, in the immediate
vicinity of the caliber of the case, causes a reaction, which
produces the recoil, and consequently the motion of the wheel. That
this effect depends, in a greater or less degree, on the composition
we use, and the manner the case is charged, is very evident. (See
_General Theory of Fire-Works_. Part 1.)
_Composition of Chinese Fire for calibers under ten-twelfths of an
inch._
Meal-powder, 16 oz.
Saltpetre, 16 --
Sulphur, 4 --
Charcoal, 4 --
Pulverized cast iron, 14 --
_Another of the same._
Meal-powder, 16 oz.
Sulphur, 3 --
Charcoal, 3 --
Pulverized cast iron, 7 --
_Another, for Palm-trees and Cascades._
Saltpetre, 12 oz.
Meal-powder, 16 --
Sulphur, 8 --
Charcoal, 4 --
Pulverized cast iron, 10 --
_Another, white, for calibers of eight and ten-twelfths of an inch._
Saltpetre, 16 oz.
Sulphur, 8 --
Meal-powder, 16 --
Pulverized cast iron, 12 --
_Another, for Gerbes of ten, and eleven-twelfths and one inch
caliber._
Saltpetre, 1 oz.
Sulphur, 1 --
Meal-powder, 8 --
Charcoal, 1 --
Pulverized cast iron, 8 --
It may be proper to remark, that the above formulæ are all approved;
as they have been used in France, and are given on the authority of
Morel and Bigot. We are informed, indeed, that these proportions
produce the most perfect fire, which surpasses the fire of the
Chinese. From the many experiments made in France, instituted with
the view of determining the best proportions, and leading, in fact,
to the improvement of the original composition, we do not hesitate to
give them the preference over all others.
In the composition of wheel-cases, Chinese fire is sometimes used,
and then only for decoration; but in nearly all the compositions
employed, in wheel-works, for standing or fixed cases, sun-cases, &c.
steel-dust forms a constituent part. The proportion it bears to other
substances is various: _viz._ to meal-powder, as one to five, one to
ten, &c. In one of the formulæ for brilliant fire, the proportion
is still greater, and in another less; but by mixing seven and a
half ounces of steel-dust with meal-powder, saltpetre, and sulphur
in the proportion of eleven pounds, one pound two ounces, and four
ounces respectively, a composition is formed, calculated to produce a
brilliant fire. But as this subject will be considered, when we treat
of wheel-works, standing pieces, &c. and the different compositions
appertaining thereto, we would only observe, that Chinese fire should
always be preferred, where the object is decidedly appearance, with
brilliancy and splendour.
_Sec. IV. Of Bengal Lights._
We have had occasion to mention heretofore, that metallic as well as
the crude, or sulphuret of, antimony, entered as a component part
into some compositions, in order to vary the effect and appearance
of the flame. That this is the effect, in the composition, which
constitutes the Bengal lights, is a fact well known, and to which its
particular character is owing.
Bengal lights, in consequence of the whiteness and brilliancy of
their flame, are considered as highly important in fire-works. The
composition was a long time kept secret, and artists were at a loss
to compound it, for those who possessed the secret, it appears,
would not divulge it. Simple as it is, it was not known, until many
experiments were made, which proved its identity with the original
Bengal composition; and, since that time, it has been confirmed by
the original formula. Morel assures us, that he purchased the secret.
_Composition of Bengal Lights._
Saltpetre, 3 lbs.
Sulphur, 13 oz. 4 dr.
Antimony, 7 oz. 4 dr.
They are pulverized and mixed in the usual manner, and passed three
times through a hair sieve. Any quantity may be made at one time. The
composition is usually put in earthen vessels, without decorations.
They may be of different sizes, and, in fact, as broad as they are
high, sufficiently large, however, to contain the composition. A
small quantity of dry meal-powder is scattered over its surface, and
a sheet of paper is tied on to secure it. It is primed with port fire
match.
The _effect_ of this mixture is evidently that of the combustion
of the sulphuret of antimony, as well as of the sulphur. The nitre
furnishes the oxygen to both, and, as the combustion is rapid, the
metal is oxidized, probably forming the antimonic acid, as the
antimony may be oxidized to the maximum. There is another view, in
which this combustion may be considered. According to the present
theory of the formation of sulphuric acid, by the combustion of
sulphur, and nitre in leaden chambers, it appears, that sulphurous
acid is first produced, and nitric oxide gas, (deutoxide of azote),
is also formed; and that the latter by uniting with the oxygen of the
air is changed into nitrous acid, which is _then_ acted upon by the
sulphurous acid, and is decomposed. Part of its oxygen combines with
the sulphurous acid, changing it into the sulphuric, and deutoxide of
azote is reproduced. In all probability, then, in the combustion of
the composition of Bengal lights, the nitric oxide itself may affect
the combustion of the antimony, which, as it would be enveloped
in nitrous acid vapour, arising from the union of nitrous gas and
oxygen, may present, in a measure, one of those cases of combustion,
in which nitric oxide acts as a supporter, affording on that account
a particular phenomenon. Reasoning _a posteriori_, this may be
affected again by the formation of sulphuric acid; for a part of the
sulphurous acid may be changed into sulphuric, not by its immediate
union with the oxygen of the nitre, according to the old theory, but
by the decomposition of the vapour of nitrous acid. This conclusion,
however, is sufficient, that the nitre is decomposed, and during its
decomposition, the sulphur and antimony are brought into action; that
a large quantity of caloric and light is evolved, whether from the
oxygen gas of the atmosphere, or the substances themselves we will
not stop to inquire; and, that, in the act of combustion, the sulphur
and antimony are acidified, forming new products.
It will be seen, by examining the formulæ for the composition of
the white and blue-lances, that they both contain antimony, but in
different proportions: thus, in the white lance, the proportion
of antimony is as one to eight of sulphur, as one to sixteen of
saltpetre, and as one to four of meal-powder; and in the blue-lance,
as it is composed only of saltpetre and antimony, the proportion of
the latter to the former is as eight to sixteen. In the composition
of Italian roses, or fixed stars, the proportion of antimony is
still smaller, and is as one to ten of sulphur, one to sixteen of
saltpetre, and one to twelve of meal-powder. Now, by comparing these
proportions with those which constitute the Bengal light composition,
they will be found to differ from those compositions, into which the
same substances enter; for, in the Bengal lights, the proportion of
the antimony to the sulphur is as five to nine, and to the saltpetre,
as five to thirty-two, or thereabout.
The inference we draw, therefore, is, that the white lance
composition differs from the blue, in containing meal-powder and
sulphur, and the latter from the former, in containing no sulphur,
but eight times as much antimony; that the white-lance composition
varies from the Bengal light, by containing one-half less of
saltpetre, one-fifth less of antimony, and one-ninth less of
sulphur; and that the Bengal composition differs from the blue lance
composition, in having double the quantity of saltpetre, nine parts
of sulphur, (the blue-light having none,) and nearly one-third less
of antimony. If we attend to these proportions of the antimony, with
the other ingredients, in the respective preparations, we will find,
that the difference, in the proportions of the antimony, produces,
with the presence or absence of the meal-powder and sulphur, and
the difference also in the quantity of the latter, the phenomena
or effects which characterise them. It is thus, therefore, with
this, as with other preparations; only vary the proportions, and
institute new equivalents, as it were, in any particular preparation,
and adopt some and reject other substances, and the effects are
varied agreeably thereto; and, if improvements are to be made in
any composition, they can only be effected by experiment, and the
investigation of the effects of new proportions, a comparison of
which, with the effect of any particular composition, prepared
according to a given formula, can alone determine the relative value
of any new formula.
_Sec. V. Of Roman Candles._
Roman candles are formed on a roller seven-twelfths of an inch in
diameter, and are generally fifteen inches in length. They are
choaked at one end, and tied in the usual manner. According to the
nature of the charge, which we shall mention, their effect is to
throw out brilliant stars, to the height of one hundred and more
feet, and when arranged with marrons, they finish with a report.
After the cases are formed, and ready to be filled, the operation is
performed with expedition, by tying a number of them together, and
charging them in that manner. The cases are charged with the rocket
composition, heretofore described, in the following way: A ladleful
of composition is put in, and rammed, using seven or eight blows with
the mallet; a small spoonful of powder is then added, and afterwards
a moulded star. This star should fit the caliber of the case. More
of the composition is then added, then meal-powder, and afterwards
a star, and these are repeated in the same order, till the case is
completely charged. Care must be taken in observing this order,
otherwise the effect would be destroyed. In striking with the mallet,
attention must also be paid, that the blows are not too violent, or
the star might be destroyed. When the cases, or candles, are charged,
we untie them, and roll some coarse paper round each end of them, at
the extremity, and round the choak.
We may remark, that in the charging of Roman candles, as their effect
depends greatly on the appearance of the stars, which issue out in
succession, too much care cannot be used in preserving the star
composition entire. To do this, much art is required in putting in,
and ramming, the rocket composition, so as not to injure or break
it. The quantity of gunpowder to each star must be small, otherwise
it might burst the case. Roman candles may be fired singly or
several at a time, according to the effect required. To fire one in
a chandelier, for instance, it is only necessary to prime it with
priming paste; but, if we wish to form batteries in an artificial
fire-work, in order to produce a variety, or to mount them on fixed
or moveable pieces, we may, if necessary, terminate their effect with
marrons, which may be effected by uniting them in such a way as to
make the fire of the one, at a given time, communicate to the other.
This communication is usually made through the choak, by attaching a
match, which is carried to the mouth of the marron; so that, when the
candle has burnt out, the last portion of the fire may pass to the
marron, the effect of which is instantaneous. If necessary, priming
paste may be used to facilitate the communication of the fire. The
marron may be fixed directly under the bottom of the candle, by
making the whole solid by a paper cylinder, which fits over the ends
of both.
The mosaic candles, as well as mosaic simples, are formed in cases
of the same thickness as sky-rockets, from which they differ in the
introduction of stars along with the composition. We may remark,
also, that they are rolled without pasting; and although Morel
recommends choaking the cases, yet a writer of more recent date, M.
Bigot, whose practical knowledge must be great, recommends _plugging_
them on the stick or roller. This is done by merely turning the end
down about half an inch, and then beating it. Before the composition
is added, he advises, also, the introduction of two or three fingers'
thickness of clay, which is rammed very solid. This answers for a
base, and supersedes the necessity of choaking. If, as we before
remarked, it is necessary to communicate fire from this end to a
marron or any other case, the clay must be bored to the composition,
and quickmatch inserted; or, instead of this, the case itself, above
the clay, may be perforated, and a communication in this way made.
Besides the ordinary Roman candles, intended expressly for
exhibition, there is another preparation, which goes under the name
of the incendiary Roman candle, used for the purposes of war. This
preparation is composed of three parts of sulphur, four parts of
saltpetre, one part of antimony, and half a part of meal-powder; but
this, together with the incendiary stars, we purpose to consider when
we treat of _Military Fire-works_.
_Sec. VI. Of Mosaic Simples._
Mosaic simples are in reality nothing more than a variety of the
Roman candle, being formed in the same manner, and of the same
composition, except that the moulded stars are different, and
produce another effect. The mosaic simples produce merely a tail,
or spout of fire; whereas the Roman candle throws out a brilliant
star. They may be used with marrons in the same manner as the Roman
candle. The length of the case is fifteen inches, and seven-twelfths
of an inch in diameter. Mosaic simples are very appropriate to
terminate a piece. A number of cases may be used by placing them
in such a manner, that their fires may cross each other, an effect
more striking than the ordinary mode of exhibition. This may be
accomplished by arranging them, two and two, to a horizontal stick,
observing that their mouths are up, and that they cross each other.
They are lashed to the stick, and leaders are carried from the mouth
of one to the mouth of another. This communication is so managed,
that two pieces discharge at the same time. They may be employed in a
variety of ways, according to fancy.
Sometimes pyramids forty or fifty feet high are furnished on each
side, with cases of mosaic simples, with a star at the summit, and
white and coloured lances differently dispersed.
The curtain of fire, produced by so many cases, the height to
which it rises, the appearance of the star with the variegated and
diversified effect of the coloured lances, all contribute to the
splendour of this arrangement.
_Composition of the Mosaic Moulded Stars._
Saltpetre, 4 oz.
Sulphur, 4 dr.
Meal-powder, 16 oz.
Charcoal, 3 --
Or in proportional parts: saltpetre, four parts; sulphur, half a
part; meal-powder, sixteen parts; and charcoal, three parts.
These substances, being finely pulverized, and intimately mixed in
the usual manner, are combined with gum-water, &c. as directed for
preparing _stars_, and cut into lozenges, which are then rolled in
priming powder, and dried in the shade.
_Sec. VII. Of Mosaic Tourbillons._
We may merely remark, as we have mentioned tourbillons heretofore,
that the cases for the mosaic tourbillons, by which name they are
designated, are seven inches in length, five-twelfths of an inch in
interior diameter, and nine-twelfths in exterior diameter; and that
the composition with which they are charged, is composed of sixteen
parts of meal-powder, and three and a half parts of pulverized
charcoal. See _Tourbillon_.
_Sec. VIII. Of Hydrogen Gas in Fire-Works._
M. Diller, some years since, exhibited at the pantheon of Paris,
artificial fire produced by the combustion of hydrogen gas. From
the short account we have of this exhibition in the _Dictionnaire
de l'Industrie_, vol. iii, p. 39, it seems, that he employed three
different airs, or gases, and produced three different flames:
viz. white, blue, and green, which were made by the mixture of the
three gases; and that he represented very perfectly, suns, stars,
triangles, the cross of Malta, and sundry figures of animals in
motion.
We may remark, that, if hydrogen gas be pure, the flame is of a
yellowish-white; but this, however, is seldom the case, as the gas is
always more or less impure, and, according to the substances it may
hold in solution, so is the flame tinged. It is most usually reddish,
because the gas holds in solution a little charcoal. In Cartwright's
fire, ether is always mixed with the whole, or a _part_ of the gas,
which is brought to the state of vapour by the application of a
gentle heat, or even by immersing the bladder of gas, which contains
the liquid ether, in hot water.
When combined with arsenic, in the form of arsenuretted hydrogen
gas, hydrogen burns with a blue flame; combined with phosphorus it
takes fire spontaneously, producing a white flame with a beautiful
corona, caused by the formation of water; and when combined with
sulphur, forming sulphuretted hydrogen or hepatic gas, it burns with
a bluish-red flame, and a quantity of sulphur is deposited. Various
mixtures of hydrogen with other gases, in due proportions, will
produce different coloured flames; so that, by paying attention to
this circumstance, the same variety of appearances may be produced,
as in Diller's exhibition.
Bladders, (or sacks made of oiled silk, which are preferable), when
filled with gas, and connected with tubes, revolving jets, &c. bent
in different directions, and formed into various figures, and pierced
with holes of different sizes, will, when pressure is applied, allow
the gas to pass through the different tubes, jets, &c. which, when
inflamed, will represent the sun and stars. If to this be added,
triangular tubes, tubes in the form of the cross of Malta, or any
other figure, they being pierced in their sides with a great number
of holes not larger than the point of a pin; it is obvious, that
fixed pieces may be represented, as well as revolving ones. In this
manner, Diller must have made his exhibition.
Hydrogen gas is usually made, by pouring on zinc, or iron filings,
in a gas bottle, sulphuric acid diluted with six times its weight of
water. The latter is decomposed; its oxygen unites with the metal,
and while the oxide is taken up by the acid, the hydrogen passes off
in the form of gas. The gas may be received directly in the bladder
or bag.
The _inflammable air pistol_ is nothing more than a hollow metallic
cylinder, or an instrument in the shape of two cones joined base to
base, and furnished with a touch-hole, and handle. This pistol is
filled with a mixture of hydrogen and oxygen gases, or in lieu of the
latter, atmospheric air; a plug or stopper is put in the caliber,
and, when the touch-hole is brought in contact with a lighted taper,
an explosion will take place, and the plug be sent out with much
force. The same effect may be shown by passing the electric spark
over the touch-hole, and hence, on an insulated stool, a person,
charged with electricity, may set it off by the finger or nose. This
pistol is usually called the Voltaic pistol, from Volta, who is said
to have invented it.
M. Biot (_Traité de Physique Experimentale_, &c. tome ii, p. 435)
describes the Voltaic pistol as a metallic vessel of a spheroid
shape, furnished with an aperture and pipe, and with a conductor for
the electric fluid, which passes through the middle of the vessel.
This conductor is insulated, as it goes through a glass tube, and
extends to within an eighth of an inch of the middle; and directly
opposite to this conductor is a metallic wire, having, like the first
conductor, a small metallic ball on its end. This conductor is placed
a short distance from the first; so that, when the electric fluid is
conducted, it passes from one ball to the other within the pistol,
and hence inflames the hydrogen gas. With respect to the form of
the pistol, it is of no moment whether it be cylindrical, conical,
or globular, as the effect is the same, provided that it contain a
sufficient quantity of gas, and the spark is conveyed through the
gas, or the gas is inflamed by a vent. The air pistol described
by Brande (_Brande's Chemistry_) is cylindrical, or rather in the
shape of a cannon, and, where the touch-hole should be, there is an
insulated conductor, which conveys the spark to the interior.
The _Voltaic lamp_ is also a contrivance by which hydrogen gas
is inflamed by the electric spark, which sets fire to a taper.
The original lamp has been greatly improved, and simplified. The
eudiometer of Volta is another contrivance by which hydrogen gas is
burnt, in a strong tube, by the electric spark.
The detonation of inflammable air may be shown over a pneumatic
tub, by filling metallic gas-holders with a mixture of hydrogen
gas and atmospheric air. When flame is brought in contact with the
mouth of the gas-holder, an explosion will immediately take place.
Soap-bubbles, blown with hydrogen gas, mixed with atmospheric air,
will take fire, on presenting a lighted taper, and give a slight
explosion. The ascension of these bubbles demonstrates, that the gas
is lighter than atmospheric air, and it is its extreme levity that
fits it for the purpose of filling balloons. It may be made twelve
times specifically lighter than atmospheric air, by passing it over
dry muriate of lime, in order to absorb the moisture it may contain,
provided the gas be free from carbon, or carbonic acid.
Light carburetted hydrogen gas, or _fire-damp_ of miners, is that
gas, which so often formerly produced many dreadful accidents by its
explosion. The invention, by Sir H. Davy, of the safety-lamp prevents
this effect.
The principle of this most valuable discovery, appears to be
altogether in the fine metallic gauze case, which surrounds the
flame of the lamp; so that, as it is found by numerous and repeated
experiments, the inflammable air, if present, cannot take fire
outside of the gauze; in other words, the flame, in the interior of
the case, is prevented from setting fire to the exterior atmosphere,
however explosive it may be.
Hydrogen gas, in combination with carbon, is not only generated
in mines and coal pits, (in the latter of which, it is the most
abundant), but is frequently found on the surface of springs in the
form of bubbles, usually however combined with sulphur; and in many
places on the surface of the earth. It may be inflamed by a candle.
The burning springs consist of this gas which is set on fire, and
the combustion is kept up by a constant supply of gas from the same
source. In the East, this gas is very often conveyed under ground
through hollow reeds, and is constantly kept burning. At other times,
it is conveyed to the sacred temples, as with the Zoroasters, and
burnt as _holy fire_; and in some countries, it is so abundant,
that the natives employ it as fuel for boiling their pots. It is
found in different parts of the United States. A striking incident,
showing its effects, occurred lately near Cincinnati, in the state
of Ohio. It appears, that, in making an excavation, and boring for
salt water, the workmen penetrated their augur into a cavity, which
contained an abundance of gas, and which, with the water, made its
way to the excavation. Not suspecting that the gas was inflammable,
or being unacquainted with it, and apprehending no danger, they
brought a lighted taper; and the gas, being mixed with atmospheric
air, exploded with a noise so considerable, that it was heard several
miles in the neighbourhood. The men were much burnt, some of them
dangerously.
The gas was afterwards inflamed by applying a taper, as it rose in
bubbles from the surface of the water.
The philosophical candle is nothing more than hydrogen gas set on
fire as it proceeds from a capillary tube, being formed in a bottle
to which the tube is attached. The most brilliant flame, however, is
produced by hydroguret of carbon, or olefiant gas.
Inflammable air is often generated in the stomachs of dead persons,
for, on applying a lighted candle, the _vapour_ has been known to
take fire. Dr. Swediaur relates some instances of the same kind, but
in living persons, in which the _urine_ of the by standers was made
use of. According to several authorities, combustion has been known
to take place spontaneously in living persons. Lair, however, is of
opinion, that, in these cases, it must have occurred by some slight
external cause, such as the fire of a candle, taper, or pipe. There
can be no question as to the developement of hydrogen gas.
Morse, (_Universal Geography_, article Persia, p. 588), after
mentioning the Persian _guebres_, the disciples and successors of the
ancient magi, and followers of Zoroaster, speaks of a combustible
ground about ten miles distant from Baku, a city in the north of
Persia, as the place for their devotion. This ground contains several
old temples, and is remarkable for the quantity of inflammable
air it emits, which is employed to produce the _sacred flame of
universal fire_. If the ground be penetrated with a stick, there will
issue out such a prodigious quantity of inflammable air, as, when
lighted, will burn for a considerable time. This gas, we remarked, is
employed there for lighting, cooking, and other purposes. The naphtha
districts, in Persia, furnish this gas in abundance. See _Naphtha_.
A Sandusky (Ohio) paper states, that, about one mile and a quarter
from Milan, is a place just in the edge of the water of Huron river,
where there is a current of inflammable gas, that burns with a clear
bright blaze, and is in sufficient quantity to light ten houses.