[1] In the United States a special officer called a "fire-marshal"
has for some time been allocated to this work in many cities, and in
1894 state fire-marshals were authorized in Massachusetts and in
Maryland, this example being followed by Ohio (1900), Connecticut
(1901), and Washington (1902); and in other states laws have been
passed making official inquiry compulsory. In England the question
has been mooted whether coroners, even where no death has occurred,
should hold similar inquiries, but though this has been done in
recent years in the City of London no regular system exists.
[2] See Thomas C. Martin, _Municipal Electric Fire Alarm and Police
Patrol Systems_ (Washington, 1904), Bulletin II of the Bureau of the
Census, Department of Commerce and Labour. The next plant was
installed in Philadelphia in 1855; one in St Louis was completed in
1858; and work was begun in New Orleans and Baltimore in 1860.
FIREBACK, the name given to the ornamented slab of cast iron protecting
the back of a fireplace. The date at which firebacks became common
probably synchronizes with the removal of the fire from the centre to
the side or end of a room. They never became universal, since the
proximity of deposits of iron ore was essential to their use. In England
they were confined chiefly to the iron districts of Sussex and Surrey,
and appear to have ceased being made when the ore in those counties was
exhausted. They are, however, occasionally found in other parts of the
country, and it is reasonable to suppose that there was a certain
commerce in an appliance which gradually assumed an interesting and even
artistic form. The earlier examples were commonly rectangular, but a
shaped or gabled top eventually became common. English firebacks may
roughly be separated into four chronological divisions--those moulded
from more than one movable stamp; armorial backs; allegorical,
mythological and biblical slabs with an occasional portrait; and copies
of 17th and 18th century continental designs, chiefly Netherlandish. The
fleur-de-lys, the rosette, and other motives of detached ornament were
much used before attempts were made to elaborate a homogeneous design,
but by the middle of the 17th century firebacks of a very elaborate type
were being produced. Thus we have representations of the Crucifixion,
the death of Jacob, Hercules slaying the hydra, and the plague of
serpents. Coats of arms were very frequent, the royal achievement being
used extensively--many existing firebacks bear the arms of the Stuarts.
About the time of Elizabeth the coats of private families began to be
used, the earliest instances remaining bearing those of the Sackvilles,
who were lords of a large portion of the forest of Anderida, which
furnished the charcoal for the smelting operations in our ancient
iron-fields. To the armorial shields the date was often added, together
with the initials of the owner. The method of casting firebacks was to
cut the design upon a thick slab of oak which was impressed face
downwards upon a bed of sand, the molten metal being ladled into the
impression. Firebacks were also common in the Netherlands and in parts
of France, notably in Alsace. At Strassburg and Metz there are several
private collections, and there are also many examples in public museums.
The museum of the Porte de Hal at Brussels contains one of the finest
examples in existence with an equestrian portrait of the emperor Charles
V., accompanied by his arms and motto. When monarchy was first destroyed
in France the possession of a _plaque de cheminee_ bearing heraldic
insignia was regarded as a mark of disaffection to the republic, and on
the 13th of October 1793 the National Convention issued a decree giving
the owners and tenants of houses a month in which to turn such firebacks
with their face to the wall, pending the manufacture by the iron
foundries of a sufficient number of backs less offensive to the instinct
of equality. Very few of the old plaques were however removed, and to
this day the old chateaux of France contain many with their backs
outward. Reproductions of ancient chimney backs are now not infrequently
made, and the old examples are much prized and collected.
FIRE BRAT, a small insect (_Thermobia_ or _Thermophila furnorum_)
related to the silverfish, and found in bakehouses, where it feeds upon
bread and flour.
FIREBRICK.--Under this term are included all bricks, blocks and slabs
used for lining furnaces, fire-mouths, flues, &c., where the brickwork
has to withstand high temperature (see BRICK).
The conditions to which firebricks are subjected in use vary very
greatly as regards changes of temperature, crushing strain, corrosive
action of gases, scouring action of fuel or furnace charge, chemical
action of furnace charge and products of combustion, &c., and in order
to meet these different conditions many varieties of firebricks are
manufactured.
Ordinary firebricks are made from fireclays, i.e. from clays which
withstand a high temperature without fusion, excessive shrinkage or
warping. Many clays fulfil these conditions although the term "fireclay"
is generally restricted in use to certain shales from the Coal Measures,
which contain only a small percentage of soda, potash and lime, and are
consequently highly refractory. There is no fixed standard of
refractoriness for these clays, but no clay should be classed as a
fireclay which has a fusion point below 1600 deg. C.
Fireclays vary considerably in chemical composition, but generally the
percentage of alumina and silica (taken together) is high, and the
percentage of oxide of iron, magnesia, lime, soda and potash (taken
together) is low. Other materials, such as lime, bauxite, &c., are
also used for the manufacture of firebricks where special chemical or
other properties are necessary.
The suitability of a fireclay for the manufacture of the various
fireclay goods depends upon its physical character as well as upon its
refractoriness, and it is often necessary to mix with the clay a
certain proportion of ground firebrick, ganister, sand or some similar
refractory material in order to obtain a suitable brick. Speaking
generally, fireclay goods used for lining furnaces where the firing is
continuous, or where the lining is in contact with molten metal or
other flux, are best made from fine-grained plastic clays; whereas
firebricks used in fire-mouths and other places which are subjected to
rapid changes of temperature must be made from coarser-grained and
consequently less plastic clays. In all cases care should be taken to
obtain a texture and also, as far as possible, by selection and
mixing, to obtain a chemical composition suitable for the purpose to
which the goods are to be applied. The Coal Measure clays often
contain nodules of siderite in addition to the carbonate of iron
disseminated in fine particles throughout the mass, and these nodules
are carefully picked out as far as practicable before the clay is
used.
A firebrick suitable for ordinary purposes should be even and rather
open in texture, fairly coarse in grain, free from cracks or warping,
strong enough to withstand the pressure to which it may be subjected
when in use, and sufficiently fired to ensure practically the full
contraction of the material. Very few fireclays meet all these
requirements, and it is usual to mix a certain proportion of ground
firebrick, ganister, sand or clay with the fireclay before making up.
The fireclay or shale or other materials are ground either between
rollers or on perforated pans, and then passed through sieves to
ensure a certain size and evenness of grain, after which the clay and
other materials are mixed in suitable proportion in the dry state,
water being generally added in the mixing mill, and the bricks made up
from plastic or semi-plastic clay in the ordinary way.
The proportion of ground firebrick, &c., used depends on the nature of
the clay and the purpose for which the material is required, but
generally speaking the more plastic clays require a higher percentage
of a plastic material than the less plastic clays, the object being to
produce a clay mixture which shall dry and fire without cracking,
warping or excessive shrinkage, and which shall retain after firing a
sufficiently open and even texture to withstand alternate heatings and
coolings without cracking or flaking. For special purposes special
mixtures are required and many expedients are used to obtain fireclay
goods having certain specific qualities. In preparing clay for the
manufacture of ordinary fire-grate backs, &c., where the temperature
is very variable but never very high, a certain percentage of sawdust
is often mixed with the fireclay, which burns out on firing and
ensures a very open or porous texture. Such material is much less
liable to splitting or flaking in use than one having a closer
texture, but it is useless for furnace lining and similar work, where
strength and resistance to wear and tear are essential. For the
construction of furnaces, fire-mouths, &c., the firebrick used must be
sufficiently strong and rigid to withstand the crushing strain of the
superimposed brickwork, &c., at the highest temperature to which they
are subjected.
The wearing out of a firebrick used in the construction of furnaces,
&c., takes place in various ways according to the character of the
brick and the particular conditions to which it is subjected. The
firebrick may waste by crumbling--due to excessive porosity or
openness of texture; it may waste by shattering, due to the presence
of large pebbles, pieces of limestone, &c.; it may gradually wear away
by the friction of the descending charge in the furnace, of the solid
particles carried by the flue gases and of the flue gases themselves;
it may waste by the gradual vitrification of the surface through
contact with fluxing materials: in cases where it is subjected to very
high temperature it will gradually vitrify and contract and so split
and fall away from the setting. It is a well-recognized fact that
successive firings to a temperature approaching the fusion point, or
long continued heating near that temperature, will gradually produce
vitrification, which brings about a very dense mass and close texture,
and entirely alters the properties of the brick.
Where firebricks are in contact with the furnace charge it is
necessary that the texture shall be fairly close, and that the
chemical composition of the brick shall be such as to retard the
formation of fusible double silicates as much as possible. Where the
furnace charge is basic the firebrick should, generally speaking, be
basic or aluminous and not siliceous, i.e. it should be made from a
fireclay containing little free silica, or from such a fireclay to
which a high percentage of alumina, lime, magnesia, or iron oxide has
been added. For such purposes firebricks are often made from materials
containing little or no clay, as for example mixtures of calcined and
uncalcined magnesite; mixtures of lime and magnesia and their
carbonates; mixtures of bauxite and clay; mixtures of bauxite, clay
and plumbago; bauxite and oxide of iron, &c.
In certain cases it is necessary to use an acid brick, and for the
manufacture of these a highly siliceous mineral, such as chert or
ganister, is used, mixed if necessary with sufficient clay to bind the
material together. Dinas fireclay, so-called, and the ganisters of the
south Yorkshire coal-fields are largely used for making these
siliceous firebricks, which may be also used where the brickwork does
not come in contact with basic material, as in the arches, &c., of
many furnaces. It is evident that no particular kind of firebrick can
be suitable for all purposes, and the manufacturer should endeavour to
make his bricks of a definite composition, texture, &., to meet
certain definite requirements, recognizing that the materials at his
disposal may be ill-adapted or entirely unsuitable for making
firebricks for other purposes. In setting firebricks in position, a
thin paste of fireclay and water or of material similar to that of
which the brick is composed, must be used in place of ordinary mortar,
and the joints should be as close as possible, only just sufficient of
the paste being used to enable the bricks to bed on one another.
It has long been the practice on certain works to wash the face of
firebrick work with a thin paste of some very refractory
material--such as kaolin--in order to protect the firebricks from the
direct action of the flue gases, &c., and quite recently a thin paste
of carborundum and clay, or carborundum and silicate of soda has been
more extensively used for the same purpose. So-called carborundum
bricks have been put on the market, which have a coating of
carborundum and clay fired on to the firebrick, and which are said to
have a greatly extended life for certain purposes. It is probable that
the carborundum gradually decomposes in the firing, leaving a thin
coating of practically pure silica which forms a smooth, impervious
and highly-refractory facing. (J. B.*; W. B.*)
FIREFLY, a term popularly used for certain tropical American
click-beetles (_Pyrophorus_), on account of their power of emitting
light. The insects belong to the family _Elateridae_, whose characters
are described under COLEOPTERA (q.v.). The genus _Pyrophorus_ contains
about ninety species, and is entirely confined to America and the West
Indies, ranging from the southern United States to Argentina and Chile.
Its species are locally known as _cucujos_. Except for a few species in
the New Hebrides, New Caledonia and Fiji, the luminous _Elateridae_ are
unknown in the eastern hemisphere. The light proceeds from a pair of
conspicuous smooth ovoid spots on the pronotum and from an area beneath
the base of the abdomen. Beneath the cuticle of these regions are
situated the luminous organs, consisting of layers of cells which may be
regarded as a specialized portion of the fat-body. Both the male and
female fireflies emit light, as well as their larvae and eggs, the egg
being luminous even while still in the ovary. The inhabitants of
tropical America sometimes keep fireflies in small cages for purposes of
illumination, or make use of the insects for personal adornment.
The name "firefly" is often applied also to luminous beetles of the
family _Lampyridae_, to which the well-known glow-worm belongs.
FIRE-IRONS, the implements for tending a fire. Usually they consist of
poker, tongs and shovel, and they are most frequently of iron, steel, or
brass, or partly of one and partly of another. The more elegant brass
examples of the early part of the 19th century are much sought after for
use with the brass fenders of that date. They were sometimes hung from
an ornamental brass stand. The fire-irons of our own times are smaller
in size and lighter in make than those of the best period.
FIRENZUOLA, AGNOLO (1493-c. 1545), Italian poet and litterateur, was
born at Florence on the 28th of September 1493. The family name was
taken from the town of Firenzuola, situated at the foot of the
Apennines, its original home. The grandfather of Agnolo had obtained the
citizenship of Florence and transmitted it to his family. Agnolo was
destined for the profession of the law, and pursued his studies first at
Siena and afterwards at Perugia. There he became the associate of the
notorious Pietro Aretino, whose foul life he was not ashamed to make the
model of his own. They met again at Rome, where Firenzuola practised for
a time the profession of an advocate, but with little success. It is
asserted by all his biographers that while still a young man he assumed
the monastic dress at Vallombrosa, and that he afterwards held
successively two abbacies. Tiraboschi alone ventures to doubt this
account, partly on the ground of Firenzuola's licentiousness, and partly
on the ground of absence of evidence; but his arguments are not held to
be conclusive. Firenzuola left Rome after the death of Pope Clement
VII., and after spending some time at Florence, settled at Prato as
abbot of San Salvatore. His writings, of which a collected edition was
published in 1548, are partly in prose and partly in verse, and belong
to the lighter classes of literature. Among the prose works
are--_Discorsi degli animali_, imitations of Oriental and Aesopian
fables, of which there are two French translations; _Dialogo delle
bellezze delle donne_, also translated into French; _Ragionamenti
amorosi_, a series of short tales in the manner of Boccaccio, rivalling
him in elegance and in licentiousness; _Discacciamento delle nuove
lettere_, a controversial piece against Trissino's proposal to introduce
new letters into the Italian alphabet; a free version or adaptation of
_The Golden Ass_ of Apuleius, which became a favourite book and passed
through many editions; and two comedies, _I Lucidi_, an imitation of the
_Menaechmi_ of Plautus, and _La Trinuzia_, which in some points
resembles the _Calandria_ of Cardinal Bibbiena. His poems are chiefly
satirical and burlesque. All his works are esteemed as models of
literary excellence, and are cited as authorities in the vocabulary of
the Accademia della Crusca. The date of Firenzuola's death is only
approximately ascertained. He had been dead several years when the first
edition of his writings appeared (1548).
His works have been very frequently republished, separately and in
collected editions. A convenient reprint of the whole was issued at
Florence in 2 vols. in 1848.
FIRESHIP, a vessel laden with combustibles, floated down on an enemy to
set him on fire. Fireships were used in antiquity, and in the middle
ages. The highly successful employment of one by the defenders of
Antwerp when besieged by the prince of Parma in 1585 brought them into
prominent notice, and they were used to drive the Armada from its
anchorage at Gravelines in 1588. They continued to be used, sometimes
with great effect, as late as the first quarter of the 19th century.
Thus in 1809 fireships designed by Lord Cochrane (earl of Dundonald)
were employed against the French ships at anchor in the Basque Roads;
and in the War of Greek Independence the successes of the Greek
fireships against the Ottoman navy, and the consequent demoralization of
the ill-disciplined Turkish crews, largely contributed to secure for
the insurgents the command of the sea. In general, however, it was found
that fireships hampered the movements of a fleet, were easily sunk by an
enemy's fire, or towed aside by his boats, while a premature explosion
was frequently fatal to the men who had to place them in position. They
were made by building "a fire chamber" between the decks from the
forecastle to a bulkhead constructed abaft the mainmast. This space was
filled with resin, pitch, tallow and tar, together with gunpowder in
iron vessels. The gunpowder and combustibles were connected by trains of
powder, and by bundles of brushwood called "bavins." When a fireship was
to be used, a body of picked men steered her down on the enemy, and when
close enough set her alight, and escaped in a boat which was towed
astern. As the service was peculiarly dangerous a reward of L100, or in
lieu of it a gold chain with a medal to be worn as a mark of honour, was
granted in the British navy to the successful captain of a fireship. A
rank of _capitaine de brulot_ existed in the French navy of Louis XIV.,
and was next to the full captain--or _capitaine de vaisseau_.
FIRE-WALKING, a religious ceremony common to many races. The origin and
meaning of the custom is very obscure, but it is shown to have been
widespread in all ages. It still survives in Bulgaria, Trinidad, Fiji
Islands, Tahiti, India, the Straits Settlements, Mauritius, and it is
said Japan. The details of its ritual and its objects vary in different
lands, but the essential feature of the rite, the passing of priests,
fakirs, and devotees barefoot over heated stones or smouldering ashes is
always the same. Fire-walking was usually associated with the spring
festivals and was believed to ensure a bountiful harvest. Such was the
Chinese vernal festival of fire. In the time of Kublai Khan the Taoist
Buddhists held great festivals to the "High Emperor of the Sombre
Heavens" and walked through a great fire barefoot, preceded by their
priests bearing images of their gods in their arms. Though they were
severely burned, these devotees held that they would pass unscathed if
they had faith. J.G. Frazer (_Golden Bough_, vol. iii. p. 307) describes
the ceremony in the Chinese province of Fo-kien. The chief performers
are labourers who must fast for three days and observe chastity for a
week. During this time they are taught in the temple how they are to
perform their task. On the eve of the festival a huge brazier of
charcoal, often twenty feet wide, is prepared in front of the temple of
the great god. At sunrise the next morning the brazier is lighted. A
Taoist priest throws a mixture of salt and rice into the flames. The two
exorcists, barefooted and followed by two peasants, traverse the fire
again and again till it is somewhat beaten down. The trained performers
then pass through with the image of the god. Frazer suggests that, as
the essential feature of the rite is the carrying of the deity through
the flames, the whole thing is sympathetic magic designed to give to the
coming spring sunshine (the supposed divine emanation), that degree of
heat which the image experiences. Frazer quotes Indian fire-walks,
notably that of the Dosadhs, a low Indian caste in Behar and Chota
Nagpur. On the fifth, tenth, and full moon days of three months in the
year, the priest walks over a narrow trench filled with smouldering wood
ashes. The Bhuiyas, a Dravidian tribe of Mirzapur, worship their tribal
hero Bir by a like performance, and they declare that the walker who is
really "possessed" by the hero feels no pain. For fire-walking as
observed in the Madras presidency see _Indian Antiquary_, vii. (1878) p.
126; iii. (1874) pp. 6-8; ii. (1873) p. 190 seq. In Fiji the ceremony is
called _vilavilarevo_, and according to an eyewitness a number of
natives walk unharmed across and among white-hot stones which form the
pavement of a huge native oven. In Tahiti priests perform the rite. In
April 1899 an Englishman saw a fire-walk in Tokio (see _The Field_, May
20th, 1899). The fire was six yards long by six wide. The rite was in
honour of a mountain god. The fire-walkers in Bulgaria are called
_Nistinares_ and the faculty is regarded as hereditary. They dance in
the fire on the 21st of May, the feast of SS. Helena and Constantine.
Huge fires of faggots are made, and when these burn down the
_Nistinares_ (who turn blue in the face) dance on the red-hot embers
and utter prophecies, afterwards placing their feet in the muddy ground
where libations of water have been poured.
The interesting part of fire-walking is the alleged immunity of the
performers from burns. On this point authorities and eyewitnesses differ
greatly. In a case in Fiji a handkerchief was thrown on to the stones
when the first man leapt into the oven, and what remained of it snatched
up as the last left the stones. Every fold that touched the stone was
charred! In some countries a thick ointment is rubbed on the feet, but
this is not usual, and the bulk of the reports certainly leave an
impression that there is something still to be explained in the escape
of the performers from shocking injuries. S.P. Langley, who witnessed a
fire-walk in Tahiti, declares, however, that the whole rite as there
practised is a mere symbolic farce (_Nature_ for August 22nd, 1901).
For a full discussion of the subject with many eyewitnesses' reports
_in extenso_, see A. Lang, _Magic and Religion_ (1901). See also Dr
Gustav Oppert, _Original Inhabitants of India_, p. 480; W. Crooke,
_Introd. to Popular Religion and Folklore of Northern India_, p. 10
(1896); _Folklore Journal_ for September 1895 and for 1903, vol. xiv.
P. 87.
FIREWORKS. In modern times this term is principally associated with the
art of "pyrotechny" (Gr. [Greek: pur], fire, and [Greek: techne], art),
and confined to the production of pleasing scenic effects by means of
fire and inflammable and explosive substances. But the history of the
evolution of such displays is bound up with that of the use of such
substances not only for scenic display but for exciting fear and for
military purposes; and it is consequently complicated by our lack of
exact knowledge as to the materials at the disposal of the ancients
prior to the invention of gunpowder (see also the article GREEK FIRE).
For the following historical account the term "fireworks" is therefore
used in a rather general sense.
_History._--It is usually stated that from very ancient times fireworks
were known in China; it is, however, difficult to assign dates or quote
trustworthy authorities. Pyrotechnic displays were certainly given in
the Roman circus. While a passage in Manilius,[1] who lived in the days
of Augustus, seems to bear this interpretation, there is the definite
evidence of Vopiscus[2] that fireworks were performed for the emperor
Carinus and later for the emperor Diocletian; and Claudian,[3] writing
in the 4th century, gives a poetical description of a set piece, where
whirling wheels and dropping fountains of fire were displayed upon the
_pegma_, a species of movable framework employed in the various
spectacles presented in the circus. After the fall of the Western empire
no mention of fireworks can be traced until the Crusaders carried back
with them to Europe a knowledge of the incendiary compounds of the East,
and gunpowder had made its appearance. Biringuccio,[4] writing in 1540,
says that at an anterior period it had been customary at Florence and
Siena to represent a fable or story at the Feast of St John or at the
Assumption, and that on these occasions stage properties, including
effigies with wooden bodies and plaster limbs, were grouped upon lofty
pedestals, and that these figures gave forth flames, whilst round about
tubes or pipes were erected for projecting fire-balls into the air: but
he adds that these shows were never heard of in his time except at Rome
when a pope was elected or crowned. But if relinquished in Italy, fire
festivals on the eve of St John were observed both in England and
France; the custom was a very old one in the days of Queen Elizabeth,[5]
while De Frezier,[6] writing in 1707, says it was commonly adhered to in
his time, and that on one occasion the king of France himself set a
light to the great Paris bonfire. Survivals of these curious rites have
been noted quite recently in Scotland and Ireland.[7] Early use also of
fireworks was made in plays and pageants. Hell or hell's mouth was
represented by a gigantic head out of which flames were made to
issue:[8] in the river procession on the occasion of the marriage of
Henry VII. and Elizabeth (1487) the "Bachelors' Barge" carried a dragon
spouting flames, and Hall relates that at the marriage of Anne Boleyn
(1538) "there went before the lord mayor's barge a foyst or wafter full
of ordnance, which foyst also carried a great red dragon that spouted
out wild fyre and round about were terrible monstrous and wild men
casting fire and making a hideous noise."[9] These individuals were
known as "green men." Their clothing was green, they wore fantastic
masks, and carried "fire clubs." They were sometimes employed to clear
the way at processions.[10]
Soon after the introduction of gunpowder the gunner and fireworker came
into existence; at first they were not soldiers, but civilians who
sometimes exercised military functions, and part of their duties was
intimately connected with the preparation of fireworks both for peace
and war. The emperor Charles V. brought his fireworks under definite
regulations in 1535,[11] and eventually other countries did the same.
The _ignes triumphales_ were an early form of public fireworks. Scaffold
poles were erected with trophies at their summits, while fixed around
them were tiers of casks filled with combustibles, so that they
presented the appearance of huge flaming trees; at their bases crouched
dragons or other mythical beasts. With such a display Antwerp welcomed
the archduke of Austria in 1550.[12] Then the "fire combat" came into
fashion. Helmets from which flames would issue were provided for the
performers; there were also swords and clubs that would give out sparks
at every stroke, lances with fiery points, and bucklers that when struck
gave forth a detonation and a flame. A picture of a combat with weapons
such as these will be found in Hanzelet's _Recueil de machines
militaires_ (1620). In addition, the fireworker grew to be somewhat of a
scenic artist who could devise a romantic background and fill it with
shapes bizarre, beautiful or terrific; he had to make his castle, his
cave or his rocky ravine, and people his stage with distressed damsel,
errant knight or devouring dragon. Furthermore he had to give motion to
the inanimate persons of the drama; thus his dragon would run down an
incline on hidden wheels, be actuated by a rope, or be propelled by a
rocket.[13] In 1613 at the marriage of the prince palatine to the
daughter of James, the pyrotechnic display was confided to four of the
king's gunners, who provided a fiery drama which included a giant, a
dragon, a lady, St George, a conjurer, and an enchanted castle, jumbled
up together after the approved fashion of the Spenserian legends.[14] As
time went on a more refined taste rejected the bizarre features of the
old displays, artistic merit began to creep into the designs, and an
effort was made to introduce something appropriate to the occasion. Thus
Clarmer of Nuremberg, a well-known fire-worker, celebrated the capture
of Rochelle (1613) by an adaptation of the Andromeda legend, where
Rochelle was the rock, Andromeda the Catholic religion, the monster
Heresy, and Perseus on his Pegasus the all-conquering Louis XIII.[15] In
the first half of the 17th century many books[16] on fireworks appeared,
which avoided the old grotesque ideas and advocated skill and finesse.
"It is a rare thing," says Nye (1648), "to represent a tree or fountain
in the air." The most celebrated work of them all was the _Great Art of
Artillery_ by Siemienowitz, which was considered important enough to be
translated into English by order of the Board of Ordnance, nearly eighty
years after it had appeared.[17] The classic facade now came into
fashion; on it and about it were placed emblematic figures, and disposed
around were groups of rockets, Roman candles, &c., musket barrels for
projecting stars, and mortars from which were fired shells called
balloons, which were full of combustibles. The figures were carved out
of wood which was soaped or waxed over and covered with papier mache so
that a skin was formed: this was cut vertically into two parts, removed
from the wood, formed into a hollow figure, and filled with fireworks.
National fireworks now assumed a stately and dignified appearance, and
for two centuries played a conspicuous part all over Europe in the
public expression of thanksgiving or of triumph. Representations and
sometimes accounts will be found in the British Museum[18] of the more
important English displays, from the coronation of James II. down to the
peace rejoicings of 1856, during which period national fireworks were
provided by the officials of the Ordnance. But since the days of
Ranelagh and Vauxhall fireworks have become a subject of private
enterprise, and the triumphs of such firms as Messrs Brock or Messrs
Pain at the Crystal Palace and elsewhere have been without an official
rival. (J. R. J. J.)
_Modern Fireworks._--In modern times the art of pyrotechny has been
gradually improved by the work of specialists, who have had the
advantage of being guided by the progress of scientific chemistry and
mechanics. As in all such cases, however, science is useless without the
aid of practical experience and acquired manual dexterity.
Many substances have a strong tendency to combine with oxygen, and will
do so, in certain circumstances, so energetically as to render the
products of the combination (which may be solid matter or gas) intensely
hot and luminous. This is the general cause of the phenomenon known as
fire. Its special character depends chiefly on the nature of the
substances burned and on the manner in which the oxygen is supplied to
them. As is well known, our atmosphere contains oxygen gas diluted with
about four times its volume of nitrogen; and it is this oxygen which
supports the combustion of our coal and candles. But it is not often
that the pyrotechnist depends wholly upon atmospheric oxygen for his
purposes; for the phenomena of combustion in it are too familiar, and
too little capable of variation, to strike with wonder. Two cases,
however, where he does so may be instanced, viz. the burning of
magnesium powder and of lycopodium, both of which are used for the
imitation of lightning in theatres. Nor does the pyrotechnist resort
much to the use of pure oxygen, although very brilliant effects may be
produced by burning various substances in glass jars filled with the
gas. Indeed, the art could never have existed in anything like its
present form had not certain solid substances become known which,
containing oxygen in combination with other elements, are capable of
being made to evolve large volumes of it at the moment it is required.
The best examples of these solid _oxidizing agents_ are potassium
nitrate (nitre or saltpetre) and chlorate; and these are of the first
importance in the manufacture of fireworks. If a portion of one of these
salts be thoroughly powdered and mixed with the correct quantity of some
suitable combustible body, also reduced to powder, the resulting mixture
is capable of burning with more or less energy without any aid from
atmospheric oxygen, since each small piece of fuel is in close
juxtaposition to an available and sufficient store of the gas. All that
is required is that the liberation of the oxygen from the solid
particles which contain it shall be started by the application of heat
from without, and the action then goes on unaided. This, then, is the
fundamental fact of pyrotechny--that, with proper attention to the
chemical nature of the substances employed, solid mixtures
(_compositions_ or _fuses_) may be prepared which contain within
themselves all that is essential for the production of fire.
If nitre and potassium chlorate, with other salts of nitric and chloric
acids and a few similar compounds, be grouped together as oxidizing
agents, most of the other materials used in making firework compositions
may be classed as _oxidizable substances_. Every composition must
contain at least one sample of each class: usually there are present
more than one oxidizable substance, and very often more than one
oxidizing agent. In all cases the proportions by weight which the
ingredients of a mixture bear to one another is a matter of much
importance, for it greatly affects the manner and rate of combustion.
The most important oxidizable substances employed are charcoal and
sulphur. These two, it is well known, when properly mixed in certain
proportions with the oxidizing agent nitre, constitute gunpowder; and
gunpowder plays an important part in the construction of most fireworks.
It is sometimes employed alone, when a strong explosion is required; but
more commonly it is mixed with one or more of its own ingredients and
with other matters. In addition to charcoal and sulphur, the following
oxidizable substances are more or less employed:--many compounds of
carbon, such as sugar, starch, resins, &c.; certain metallic compounds
of sulphur, such as the sulphides of arsenic and antimony; a few of the
metals themselves, such as iron, zinc, magnesium, antimony, copper. Of
these metals iron (cast-iron and steel) is more used than any of the
others. They are all employed in the form of powder or small filings.
They do not contribute much to the burning power of the composition; but
when it is ignited they become intensely heated and are discharged into
the air, where they oxidize more or less completely and cause brilliant
sparks and scintillations.
Sand, potassium sulphate, calomel and some other substances, which
neither combine with oxygen nor supply it, are sometimes employed as
ingredients of the compositions in order to influence the character of
the fire. This may be modified in many ways. Thus the rate of combustion
may be altered so as to give anything from an instantaneous explosion to
a slow fire lasting many minutes. The flame may be clear, smoky, or
charged with glowing sparks. But the most important characteristic of a
fire--one to which great attention is paid by pyrotechnists--is its
_colour_, which may be varied through the different shades and
combinations of yellow, red, green and blue. These colours are imparted
to the flame by the presence in it of the heated vapours of certain
metals, of which the following are the most important:--sodium, which
gives a yellow colour; calcium, red; strontium, crimson; barium, green;
copper, green or blue, according to circumstances. Suitable salts of
these metals are much used as ingredients of fire mixtures; and they are
decomposed and volatilized during the process of combustion. Very often
the chlorates and nitrates are employed, as they serve the double
purpose of supplying oxygen and of imparting colour to the flame.
The number of fire mixtures actually employed is very great, for the
requirements of each variety of firework, and of almost each size of each
variety, are different. Moreover, every pyrotechnist has his own taste in
the matter of compositions. They are capable, however, of being
classified according to the nature of the work to which they are suited.
Thus there are rocket-fuses, gerbe-fuses, squib-fuses, star-compositions,
&c.; and, in addition, there are a few which are essential in the
construction of most fireworks, whatever the main composition may be.
Such are the _starting-powder_, which first catches the fire, the
_bursting-powder_, which causes the final explosion, and the
_quick-match_ (cotton-wick, dried after being saturated with a paste of
gunpowder and starch), employed for connecting parts of the more
complicated works and carrying the fire from one to another. Of the
general nature of fuses an idea may be had from the following two
examples, which are selected at hazard from among the numerous recipes
for making, respectively, tourbillion fire and green stars:--
_Tourbillion_. _Green Stars_.
Meal gunpowder 24 parts. Potassium chlorate 16 parts.
Nitre 10 " Barium nitrate 48 "
Sulphur 7 " Sulphur 12 "
Charcoal 4 " Charcoal 1 "
Steel filings 8 " Shellac 5 "
Calomel 8 "
Copper sulphide 2 "
Although the making of compositions is of the first importance, it is
not the only operation with which the pyrotechnist has to do; for the
construction of the _cases_ in which they are to be packed, and the
actual processes of packing and finishing, require much care and
dexterity. These cases are made of paper or pasteboard, and are
generally of a cylindrical shape. In size they vary greatly, according
to the effect which it is desired to produce. The relations of length to
thickness, of internal to external diameter, and of these to the size of
the openings for discharge, are matters of extreme importance, and must
always be attended to with almost mathematical exactness and considered
in connexion with the nature of the composition which is to be used.
There is one very important property of fireworks that is due more to
the mechanical structure of the cases and the manner in which they are
filled than to the precise chemical character of the composition, i.e.
their power of _motion_. Some are so constructed that the piece is kept
at rest and the only motion possible is that of the flame and sparks
which escape during combustion from the mouth of the case. Others, also
fixed, contain, alternately with layers of some more ordinary
compositions, balls or blocks of a special mixture cemented by some kind
of varnish; and these _stars_, as they are called, shot into the air,
one by one, like bullets from a gun, blaze and burst there with striking
effect. But in many instances motion is imparted to the firework as a
whole--to the case as well as to its contents. This motion, various as
it is in detail, is almost entirely one of two kinds--_rotatory_ motion
round a fixed point, which may be in the centre of gravity of a single
piece or that of a whole system of pieces, and _free ascending_ motion
through the air. In all cases the cause of motion is the same, viz. that
large quantities of gaseous matter are formed by the combustion, that
these can escape only at certain apertures, and that a backward pressure
is necessarily exerted at the point opposite to them. When a large gun
is discharged, it recoils a few feet. Movable fireworks may be regarded
as very light guns loaded with heavy charges; and in them the recoil is
therefore so much greater as to be the most noticeable feature of the
discharge; and it only requires proper contrivances to make the piece
fly through the air like a sky-rocket or revolve round a central axis
like a Catherine wheel. Beauty of motion is hardly less important in
pyrotechny than brilliancy of fire and variety of colour.
The following is a brief description of some of the forms of firework
most employed:--
_Fixed Fires._--_Theatre fires_ consist of a slow composition which
may be heaped in a conical pile on a tile or a flagstone and lit at
the apex. They require no cases. Usually the fire is coloured--green,
red or blue; and beautiful effects are obtained by illuminating
buildings with it. It is also used on the stage; but, in that case,
the composition must be such as to give no suffocating or poisonous
fumes. _Bengal lights_ are very similar, but are piled in saucers,
covered with gummed paper, and lit by means of pieces of match.
_Marroons_ are small boxes wrapped round several times with lind cord
and filled with a strong composition which explodes with a loud
report. They are generally used in _batteries_, or in combination with
some other form of firework. _Squibs_ are straight cylindrical cases
about 6 in. long, firmly closed at one end, tightly packed with a
strong composition, and capped with touch-paper. Usually a little
bursting-powder is put in before the ordinary composition, so that the
fire is finished by an explosion. The character of the fire is, of
course, susceptible of great variation in colour, &c. _Crackers_ are
characterized by the cases being doubled backwards and forwards
several times, the folds being pressed close and secured by twine. One
end is primed; and when this is lit the cracker burns with a hissing
noise, and a loud report occurs every time the fire reaches a bend. If
the cracker is placed on the ground, it will give a jump at each
report; so that it cannot quite fairly be classed among the fixed
fireworks. _Roman candles_ are straight cylindrical cases filled with
layers of composition and _stars_ alternately. These stars are simply
balls of some special composition, usually containing metallic
filings, made up with gum and spirits of wine, cut to the required
size and shape, dusted with gunpowder and dried. They are discharged
like blazing bullets several feet into the air, and produce a
beautiful effect, which may be enhanced by packing stars of
differently coloured fire in one case. _Gerbes_ are choked cases, not
unlike Roman candles, but often of much larger size. Their fire
spreads like a sheaf of wheat. They may be packed with variously
coloured stars, which will rise 30 ft. or more. _Lances_ are small
straight cases charged with compositions like those used for making
stars. They are mostly used in complex devices, for which purpose they
are fixed with wires on suitable wooden frames. They are connected by
_leaders_, i.e. by quick-match enclosed in paper tubes, so that they
can be regulated to take fire all at the same time, singly, or in
detachments, as may be desired. The devices and "set pieces"
constructed in this way are often of an extremely elaborate character;
and they include all the varieties of _lettered designs_, of _fixed
suns_, _fountains_, _palm-trees_, _waterfalls_, _mosaic work_,
_Highland tartan_, _portraits_, _ships_, &c.
_Rotating Fireworks._--_Pin_ or _Catherine wheels_ are long paper
cases filled with a composition by means of a funnel and packing-wire
and afterwards wound round a disk of wood. This is fixed by a pin,
sometimes vertically and sometimes horizontally; and the outer primed
end of the spiral is lit. As the fire escapes the recoil causes the
wheel to revolve in an opposite direction and often with considerable
velocity. _Pastiles_ are very similar in principle and construction.
Instead of the case being wound in a spiral and made to revolve round
its own centre point, it may be used as the engine to drive a wheel or
other form of framework round in a circle. Many varied effects are
thus produced, of which the _fire-wheel_ is the simplest. Straight
cases, filled with some fire-composition, are attached to the end of
the spokes of a wheel or other mechanism capable of being rotated.
They are all pointed in the same direction at an angle to the spokes,
and they are connected together by leaders, so that each, as it burns
out, fires the one next it. The pieces may be so chosen that brilliant
effects of changing colour are produced; or various fire-wheels of
different colours may be combined, revolving in different planes and
different directions--some fast and some slowly. _Bisecting wheels_,
_plural wheels_, _caprice wheels_, _spiral wheels_, are all more or
less complicated forms; and it is possible to produce, by mechanism of
this nature, a model in fire of the solar system.
_Ascending Fireworks._--_Tourbillions_ are fireworks so constructed as
to ascend in the air and rotate at the same time, forming beautiful
spiral curves of fire. The straight cylindrical case is closed at the
centre and at the two ends with plugs of plaster of Paris, the
composition occupying the intermediate parts. The fire finds vent by
six holes pierced in the case. Two of these are placed close to the
end, but at opposite sides, so that one end discharges to the right
and the other to the left; and it is this which imparts the rotatory
motion. The other holes are placed along the middle line of what is
the under-surface of the case when it is laid horizontally on the
ground; and these, discharging downwards, impart an upward motion to
the whole. A cross piece of wood balances the tourbillion; and the
quick-match and touch-paper are so arranged that combustion begins at
the two ends simultaneously and does not reach the holes of ascension
till after the rotation is fairly begun. The _sky-rocket_ is generally
considered the most beautiful of all fireworks; and it certainly is
the one that requires most skill and science in its construction. It
consists essentially of two parts,--the body and the head. The body is
a straight cylinder of strong pasted paper and is choked at the lower
end, so as to present only a narrow opening for the escape of the
fire. The composition does not fill up the case entirely, for a
central hollow conical bore extends from the choked mouth up the body
for three-quarters of its length. This is an essential feature of the
rocket. It allows of nearly the whole composition being fired at once;
the result of which is that an enormous quantity of heated gases
collects in the hollow bore, and the gases, forcing their way
downwards through the narrow opening, urge the rocket up through the
air. The top of the case is closed by a plaster-of-Paris plug. A hole
passes through this and is filled with a fuse, which serves to
communicate the fire to the head after the body is burned out. This
head, which is made separately and fastened on after the body is
packed, consists of a short cylindrical paper chamber with a conical
top. It serves the double purpose of cutting a way through the air and
of holding the _garniture_ of stars, sparks, crackers, serpents, gold
and silver rain, &c., which are scattered by bursting fire as soon as
the rocket reaches the highest point of its path. A great variety of
beautiful effects may be obtained by the exercise of ingenuity in the
choice and construction of this garniture. Many of the best results
have been obtained by unpublished methods which must be regarded as
the secrets of the trade. The _stick_ of the sky-rocket serves the
purpose of guiding and balancing it in its flight; and its size must
be accurately adapted to the dimensions of the case. In _winged_
rockets the stick is replaced by cardboard wings, which act like the
feathers of an arrow. A _girandole_ is the simultaneous discharge of a
large number of rockets (often from one hundred to two hundred), which
either spread like a peacock's tail or pierce the sky in all
directions with rushing lines of fire. This is usually the final feat
of a great pyrotechnic display.
See Chertier, _Sur les feux d'artifice_ (Paris, 1841; 2nd ed., 1854);
Mortimer, _Manual of Pyrotechny_ (London, 1856); Tessier, _Chimie
pyrotechnique, ou traite pratique des feux colores_ (Paris, 1858);
Richardson and Watts, _Chemical Technology_, s.v. "Pyrotechny"
(London, 1863-1867); Thomas Kentish, _The Pyrotechnist's Treasury_
(London, 1878); Websky, _Luftfeuerwerkkunst_ (Leipzig, 1878).
(O. M.)