MILITARY PYROTECHNY
The use of pyrotechnic mixtures for military purposes is the basis of
artillery, and one might almost say the foundation of chemistry. Before
the age of the alchemist men were at work endeavouring to produce some
weapon which would give them an advantage over their enemies. Of the
natural phenomena none made so strong an appeal as fire, which from
earliest times had been a mysterious and therefore terrible element.
The early use of fire or pyrotechnic mixtures gave the users so decided
an advantage over their enemies that their use was chronicled by
historians of the day either on the side of the victors as a pæan of
praise for their invincible weapon, or as an excuse for defeat on the
side of the vanquished.
Such reports are necessarily vague and exaggerated, vague because
the writer had no technical knowledge of the subject, and the users
naturally wished for secrecy and exaggerated because exaggeration
increased the value of the weapon.
It is from such reports that we obtain our information about Greek fire
and similar compositions, and when one considers that the translations
were generally biased, in most cases unintentionally but still biased,
in favour of reading into passages referring to fire or projectiles an
early reference to gunpowder, guns or some unknown pyrotechnic effect,
it is obvious that all information so gained must be accepted with a
considerable amount of reserve.
The translators, too, in many cases were men of no technical knowledge,
which made them even more prone to fall into errors which would be
avoided by the expert.
Of the mass of writing dealing with the subject, the work of two
writers stands out prominently—the late Mr. Oscar Guttman in his
“History of Explosives,” and Col. H. W. L. Hime in his “Origin of
Artillery,” whose observations cover the field of information on the
subject, although approaching from slightly different angles.
Neither, however, gives an exact explanation satisfactorily covering
the projection of Greek or sea fire. Col. Hime, rejecting earlier
theories, goes somewhat to the other extreme: he denies the knowledge
of saltpetre before the twelfth century, but attempts to explain the
phenomenon by the use of phosphide of calcium.
He premises four conditions to be filled by the weapon or apparatus.
These conditions are fulfilled by the explanation already briefly
touched upon on page 15, and the writer is convinced that this simple
although apparently little known phenomenon is the true explanation of
the terrible, mysterious Greek or sea fire.
If a mixture of saltpetre, pitch, and sulphur is charged into a long
tube sufficiently strong and ignited it will burn, giving off dense
smoke, for a short time, when it appears to choke momentarily. This
choking is followed by a more or less violent outburst, which may
be likened to a “cough,” projecting a burning mass of composition
to a considerable distance; the action is repeated with surprising
regularity during the burning of the whole of the composition
throughout the length of the tube, and will, the writer is confident,
satisfy any unbiased observer that here is the true explanation of the
phenomenon.
Let us see how the requirements mentioned by Col. Hime are fulfilled.
The first, “It was a wet fire,” _i.e._, its action necessarily
connected in some way with water or the sea, and as a matter of fact it
was used at sea with great success on many occasions. May not a “wet
fire” be a way of saying “a molten, viscous mass of fire”? The masses
would float and although some might become extinguished, some would
probably burn on the surface of the water; also its use at sea would,
with a range up to a hundred yards, be quite as easy as on land.
Secondly, “Its composition was such as could be kept secret at
Constantinople.” If, as Col. Hime says, saltpetre as such was unknown
at the time, it was only as a separate kind of salt. It was undoubtedly
known, but not distinguished from sea salt or nitrate of soda. Would
not this fact render the concealment of the ingredients used more easy?
Thirdly, “It burned with much noise and smoke.” Allowing for some
slight exaggeration the first condition is fulfilled, as undoubtedly is
the latter.
Fourthly, “It was necessarily connected in some way with syphons.” As
Col. Hime points out, there is ambiguity between the word syphon and
tube, and if the latter word meets the facts it seems the more likely
rendering.
The writer saw this effect produced during experiments with
smoke-producing compositions, and it is probable that the mixture in
question was not in the most effective proportions, but so striking was
the result that there is little doubt that experiments on such lines
would produce a terrible and effective weapon under the conditions of
warfare then in existence.
The “Dictionnaire Mobilier Français” gives a diagram of a weapon of a
somewhat similar nature stated to have been used by the Arabs in the
fifteenth century. The illustration shows what is virtually a Roman
candle, and appears plausible until one considers the facts. What is
most probable is that the weapon, which was of an incendiary nature,
was similar to that described above, which fulfils the requirements of
the description without assuming a knowledge of compositions which at
the time did not exist.
From the period of Greek fire onward military and recreative pyrotechny
appear to have marched side by side.
As we have seen, the progress in the latter branch was extremely slow,
so with the former, and it was not until the introduction of modern or
comparatively modern methods that real progress commenced.
With the progress came divergence, the introduction of the rifled bore
in artillery, and of nitro compounds and high explosives whose dynamic
force exceeds many times that of gunpowder, which however useful they
might be to the artillerist, were of little value to the recreative
pyrotechnist. It was not until the great war that the resources of
pyrotechny were fully realised and utilised by the military. It is
curious to note that just as the tactics and methods of warfare
eventually adopted—although on an unprecedentedly large scale—were
in a great measure those of centuries before, so military pyrotechny
returned to ideas just as antiquated. With the advantages of modern
science, and by the assistance of knowledge gained in the development
of recreative pyrotechny, the progress made in a month or so in
military pyrotechny during the war may, without exaggerating, be said
to have exceeded that of previous centuries.
Speaking generally, the use of pyrotechny in warfare, or indeed any
science, has two objectives, the first to destroy or embarrass the
troops of the enemy, and secondly, to assist one’s own.
Until the late war it was the first of these which received by far the
greater attention, and it is but natural that the introduction of the
modern methods mentioned above should have provided means which left
pyrotechnics far behind. In the second division, however, pyrotechny
triumphed.
Of the offensive type the earliest use of pyrotechny was the
incendiary. Greek fire, wild fire, and similar compositions have been
used from time immemorial to set fire to enemies’ works or ships or to
injure his personnel. And just as incendiary compositions antedated
the propellant, so the incendiary shell appears to have preceded the
explosive.
Incendiary projectiles of the past were known as carcasses; the
earliest form appears to have been a canvas bag or container pitched
over on the outside and bound with iron hoops, which, from their
likeness to the ribs of a corpse—according to “Chambers’ Encyclopædia”
(1741)—suggested the name.
The fireball was similarly constructed and designed for hand
projection, bearing the same relation to the carcass as does the
grenade to the bomb.
The composition in most incendiary missiles consisted of a mixture of
saltpetre, sulphur, and pitch, with or without the addition of mealed
gunpowder.
The most recent form of carcass was a spherical shell of iron, having
three vents, and filled with incendiary composition. This projectile
became obsolete in the Service at the end of the last century.
Another form of pyrotechnic projectile was that designed to give out
smoke, either with the idea of rendering the atmosphere of works or
casemates unbearable to the defenders (a principle revived in the late
war by the use of poison gas), or to hinder them by obscuring their
vision either by firing a smoke cloud in their (the enemy’s) works, or
so placed as to hide one’s own troops.
It is open to discussion if the use of smoke is not indeed of greater
antiquity than that of incendiary missiles, but it is probable that
its origin was its production by the combustion of grass or similar
material, and not with pyrotechnic composition.
Read’s “Weekly Journal” of October 25th, 1760, in an account of a
review in Hyde Park, mentions as the concluding item of the manœuvres,
that “pieces of a new construction, of a globular form, were set on
fire, which occasioned such a smoke as to render all persons within a
considerable distance entirely invisible, and thereby the better in
time of action to secure a retreat.” There can be little doubt that
this is one of the first demonstrations, at any rate in this country,
of the use of smoke balls.
The Chinese made use of both projectiles many centuries ago, and the
smoke—or stink-pot—was in use by them until comparatively recently.
Smoke balls from 4⅖th inches up to 13 inches calibre were included in
the official list of projectiles for smooth-bore guns until about 1873,
when with ground light balls they became obsolete. The latter, as their
name suggests, were intended to be burnt on the ground and light up
enemy working parties, etc. This also was the object of the parachute
light-ball, which was fitted with a time fuse and an opening charge;
upon opening, a light was ignited suspended from a parachute. This
method appears to have been invented in Denmark in 1820, and they were
used in Austria the following year.
Another class of war store which naturally suggests itself is that used
to give light for the purpose of signalling. The light is either burnt
on the ground as a hand light or fitted to a rocket. Fireworks for
this purpose have been in use from earliest times, being the logical
development of the signal beacon, but it was not until the introduction
of genuine colour—that is to say, colour distinguishable at a long
distance—that they reached their full standard of utility.
It is, however, the rocket which has received most attention for
military purposes, and certainly with good reason. Here was a
projectile which, in the days of smooth-bore ordnance had a good
range and required no heavy gun or transport. Moreover, it formed
its own time fuse. Congreve wrote: “Rockets are ammunition without
ordnance, the soul of artillery without the body.” Many methods of
fitting up rockets for warlike purposes have been evolved, invented and
re-invented, most of which for practical purposes were useless.
It is the military use of the rocket, however, which presents the most
interesting study in military pyrotechny.
There are several early references to what is supposed to be the use of
rockets in warfare. The Paduans are stated to have burned the town of
Mestre with these projectiles.
Orleans used rockets in its defence in 1429, and Dunois fired them in
1449, when besieging the town of Pont-Andemer. In 1452 they were used
against Bordeaux, and the following year at Gand.
Rockets were employed in 1586 for lighting purposes and as projectiles
against cavalry. The description seems to indicate a method of fitting
up to produce a similar effect to a shrapnel shell.
Hanselet, writing in 1630, refers to rockets with grenades attached.
Casimir Siemienowitz, Lieut.-General of the Ordnance to the King of
Poland, published in 1650 his “Great Art of Artillery,” which contains
a treatise on fireworks both for civil and military purposes. He refers
to a work on the military use of fireworks written ninety years before,
and speaks of rockets up to 100 lbs. and describes their construction.
A French work published in 1561, entitled “Treatise upon several kinds
of War-Fireworks,” suggests a rocket case of varnished leather.
It is on record that in 1688 trials were made in Berlin with rockets
of 50 lbs. and 120 lbs., which carried a bomb weighing 16 lbs. The
composition was nine parts saltpetre, four parts sulphur, and three
parts charcoal. The case is stated to have been of wood covered with
linen.
Hyder Ali is credited with making considerable use of rockets
against our troops in India; he is said to have had a corps of 1,200
“rocketers” in 1788, whilst later on, his son, Tippoo Sahib, employed
as many as 5,000, and Captain Moritz Myer, writing in 1836, ascribes to
experience of these weapons so gained the efforts made in England to
bring them to perfection.
He also describes the Indian rocket as “an iron envelope about 8 inches
long and 1½ inches in diameter, with sharp points at the top. The stick
of bamboo 8 or 10 feet long, but sometimes consisting of an iron rod.
They were hand-thrown by the rocketers, and did much damage to the
cavalry.”
This description, which, to say the least, is unconvincing, would seem
rather to refer to some other pyrotechnic missile.
Whatever may have been the cause, there was undoubtedly great interest
in the subject of rockets during the first half of the nineteenth
century. Sir William Congreve is perhaps best known in connection with
the work of this period. His efforts, however, were rather directed to
the development of existing ideas than to invention.
In 1804, after experiments at the Royal Laboratory, Woolwich, a
flotilla of boats was fitted out under his direction for the purpose
of bombarding Boulogne Harbour with incendiary rockets from frames
fixed on the decks. The first attempt ended in a fiasco owing to heavy
weather, but the following year better results were obtained, although
the rockets were deflected by the wind and did more damage in the town
than in the harbour.
In 1807 Congreve personally superintended their use at Copenhagen
with even better effect, and they were again used in the Walcheren
Expedition and in an attack on the island of Aix.
These rockets were all of an incendiary nature, with paper cases, and
fired at an elevation of 55 degrees. Myer gives the proportion of
the composition as 62.44 saltpetre, 23.18 charcoal, 14.38 sulphur.
This writer gives Congreve’s rockets little credit for efficiency,
but admits that they “attracted great attention and were regarded as
formidable.” He remarks that at the siege of Flessingen “the rockets
acted so badly that the English themselves said that they did more harm
to the battery than the besieged town.” He also states that as a result
of finding an “unburnt specimen” in the town after the bombardment of
Copenhagen trials were conducted by Captain Schuhmacher, although how
an unburnt rocket could reach the town is not clear; possibly he means
from a reconstruction of the remains collected.
These trials seem to have been successful, and in 1808 a rocket brigade
was formed.
In 1809 Admiral Cochrane used rockets upon the town of Callao, in
1810 they were used against Cadiz, and in 1813 in the battle of
Leipsic, where the commanding officer, Captain Bogeu, was killed, and
at the siege of Dantzic. It is interesting to note that during that
year they were used for propaganda purposes. At the siege of Glogau
proclamations, etc., were printed on thin paper and fastened to the
sticks with light thread. Rockets were used with effect at Waterloo,
the rocket detachment being directed by Sergeant Dunnet.
In 1813 Colonel Augustin, of the Austrian army, saw the English rocket
batteries in action and trials of Congreve rockets in London, and the
following year visited Copenhagen, where by arrangement between the
two Powers he was instructed by Schuhmacher in his method of rocket
construction.
The Austrian Government as a result established shortly afterwards an
extensive factory at Weinerisch-Neustadt for the manufacture of war
rockets.
Much work and ingenuity was expended about this time in seeking to
eliminate the necessity of the rocket stick. Congreve is credited with
introducing fins similar in action to the feathers on an arrow; this,
however, had been done nearly one hundred years previously, and Frézier
illustrates the method in his treatise.
A Mr. Heath, of Boston, is credited with having reached a range of two
and a half-miles with a five-pound rocket of this type.
Garnier in 1813 proposed to avoid the alteration in position of the
centre of gravity by using a wire or chain with a weight at the end
fastened to the centre of the rocket and hanging vertically. From
Ruggieri’s book it would appear that this idea had often been tried
previously.
However, the most successful series of inventions were those based on
the principle of the rifle, that to give the rocket a rotary motion in
its passage through the air.
In 1815 successful trials were made in America with rockets of the
rotary type, rotation being imparted by means of holes bored through
the case into the composition in an oblique direction.
Congreve established a factory at Bow for the manufacture of rockets
for the East India Company, and Captain Parlby, of the Bengal
Artillery, manufactured similar rockets, both being made to rotate,
probably on similar lines to the American model. The “Calcutta Journal”
of the period contains a discussion of the rival merits of Congreve’s
and Parlby’s rockets.
Hale patented a rocket constructed on similar lines as late as 1844,
the holes at the side of the case being nearly tangential. He also
gave his name to a service rocket—Hale’s 24 pr. and 9 pr. These were
constructed of iron with a wooden head, fitted metal plug at the base
with three vents, a tail piece or flange continuing from the base so as
to enclose half the periphery of each jet. This arrangement imparts a
rotary motion to the rocket.
In 1853 Macintosh patented a method of rotating the tube from which the
rocket was fired so as to give an initial rotary movement before the
flight commences.
The following year Fitzmaurice patented the idea of causing rotation by
a screw-shaped head, and Court a method by which the fire impinged on
surfaces inclined to the axis of the rocket.
In 1826 Congreve patented a method of fixing two or more rockets
together so that the heading of one ignited the next and so obtained a
longer time of burning; this method is, however, again anticipated in
Frézier’s book.
About this time all the leading Powers in Europe were manufacturing
rockets for war purposes, factories for their manufacture being
established at Warsaw, Turin, Toulon, and Metz. The Russians used them
at this period in their war with Turkey, firing them in salvoes of nine.
In 1831 a series of trials were made by the Swiss military authorities
of 6 lb. rockets fired from a 6 ft. tube, when a range of from 18–1900
yards was obtained, and three hits registered out of five were made at
1,100 yards.
Although great interest was aroused by the rocket for war purposes, it
quickly subsided, and it is now practically only used for signalling
and line-carrying purposes.
William Bourne, who describes himself as a “poor gunner,” the first
to produce an original book on artillery in this country, as distinct
from translation of continental works, makes the following observations
on military pyrotechnics: “Divers gunners and other men have devised
sundry sorts of fireworks for the annoyance of their enemies, yet as
far as I have ever seen or heard, I never knew any good service done by
it, either by sea or land, but only by powder, and that has done great
service for that the force of it is so mighty and cometh with such a
terror. But for their other fireworks it is rather meet to be used in
the time of pleasure in the night rather than for any service.”