CHAPTER IX

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.”