The founding of these enormous cannon on the field of action is in itself a tribute to the energy and resourcefulness of the nation who have been described as being, at that time, the finest engineers in the world. Of the effectiveness of the Ottoman artillery there is evidence in the results achieved. Constantinople fell to the giant bombards. And in the early part of the following century Rhodes, the last outpost of the Knights, fell to the same great power. The invention of the Christians[46] was, in fact, the weapon which gave supremacy to the Infidel in the eastern part of Europe.
In the meantime the evolution of artillery was taking a new direction. The large and relatively feeble ordnance of the Turks was, in the circumstances, not entirely unsuitable for the purpose for which it was intended: the smashing of masonry and the breaching of gates and walls. The maximum of effect was obtained from a missile of enormous mass projected with a low velocity. Nevertheless its disadvantages were obvious. Large cannon cast in bronze were necessarily of great expense and weight, their discharges were few and far between, they wore rapidly and were thus short-lived, and they possessed the dangerous property of becoming brittle when heated. An increase in power and a reduction in weight were required for the achievement of a portable artillery, and the progress of mechanical science pointed to wrought iron as the material of which such an artillery might be made.
The extraction of iron in small quantities from ferruginous ore was a comparatively simple operation, even in primitive times. With the aid of bellows and a plentiful supply of wood charcoal the smith was able to make his furnace yield small masses of metallic iron of the purest quality. This iron, wrought on an anvil, could be drawn out into plate or bar as desired, the resulting metal being, by reason of the purity of the charcoal used in its extraction, of great toughness, homogeneity, and strength. In Spain and Italy were mines which had long been famed for their iron. In England the Roman had made good use of the metal found in the Sussex mines, and all through the middle ages the wealds of Kent and Sussex were the centres of the English iron trade. In the fourteenth century improved methods came into use; the adoption of water-power for driving the bellows, for crushing the charcoal, and for operating the tilt-hammers, had its effect on the development of the iron-smelting industry; higher temperatures obtained and larger masses of ore could now be treated; the iron, produced in larger quantities by improved methods, was perhaps purer and stronger than before.
In wrought iron, then, a material was available which almost alone was suitable for the manufacture of the more portable sorts of gun. By its use guns could be made strong enough, without being of an excessive weight, to withstand the increasing stresses thrown on them, first, by the use of iron bullets instead of stone, and secondly, by the discovery of an improved gunpowder. Artillery underwent a dual development. On the one hand, for use with the weak cannon powder, was the large stone-throwing ordnance, made of cast bronze or of hooped bars of iron; on the other, for use with iron shot and a stronger propellant, were various denominations of small portable and semi-portable wrought-iron guns. These two distinct types developed side by side until the middle of the sixteenth century.
The use of iron and lead balls, the superiority of which over balls of stone had doubtless been manifested in former centuries in connection with the projection of Greek fire, was practised by the Florentines soon after the invention of guns themselves. The discovery of “corned” gunpowder took place a century later.
In its original form gunpowder possessed many disadvantages as a propellant. Ground into a fine powder, and composed in the first instance of almost equal proportions of saltpetre, sulphur, and charcoal, it was peculiarly liable to accidental explosion, so that frequently the charcoal was kept separate from the other ingredients and mixed just prior to use. If kept mixed it easily disintegrated, in the shaking of transport, into three strata, the charcoal coming to the top and the sulphur sinking to the bottom. It was intensely hygroscopic, and quickly fouled the barrels of the pieces in which it was used. But, most important of all, the efficiency of its combustion depended to an inconvenient degree upon the density with which, after being ladled into the gun, it was rammed home. The greatest care had to be exercised in ramming. If pressed into too dense a mass the powder largely lost its explosive character; the flame which ignited the portion nearest the vent could not spread through the mass with sufficient speed; it quietly petered out. If rammed too loosely, on the other hand, the explosive effect was also lost. A great gain ensued therefore when, in place of the fine or “serpentine” powder, corned powder came to be used, about the middle of the fifteenth century. In this form the powder was damped and worked into grains, crushed to the requisite size and sieved for uniformity. These grains were finally glazed to prevent deterioration from the effects of damp; and the resulting powder proved stronger and more efficient in every way than the same mixture in its more primitive form.
Some time was to elapse before guns could be cast of sufficient strength to withstand the force of corned powder. “Chemistry had outrun metallurgy.” The larger species of ordnance were restricted to the use of serpentine powder until the middle of the sixteenth century. Nevertheless, cast ordnance as well as the lighter forged iron guns were developed continuously for service in the field. Named after birds and reptiles and clumsily cast of such shapes and weights as pleased the founders’ fancy, they were of use chiefly in demolishing by attrition the gates and walls of forts and cities. From the battle of Cressy onward, first in huge carts and then on their own wheeled carriages, they rumble across the pages of European history.
§
At sea the evolution of ordnance had to conform, of course, to the progress of naval architecture and the changing nature of the warfare. In the Mediterranean, where the oar-propelled galley remained for centuries the typical fighting ship, the bombard was planted in the bows, shackled to a deck-carriage upon the centre line, to give ahead fire and to supplement the effects of a powerful ram. As the galley developed, the main central gun became flanked by other bow-chasers; while on the beams and poop light wrought-iron breech-loading swivel guns formed a secondary armament whose double function was to repel boarders and to overawe its own slave-crew. In the Atlantic, where the typical fighting vessel was the lofty sailing ship, the same two different types of armament had vogue. But in this case their distribution was different; the sailing ship, with no recourse to oars for manœuvring, could not always ensure an end-on attack or defence, and had to arm herself against an enemy from any quarter. Her freedom from oars, her height, and the invention of the porthole, enabled the early “great ship” to mount a sufficiently distributed all-round armament. While her sides were pierced for ponderous bombards, her poop and forecastle bristled with the same light secondary armament as figured in the Mediterranean galley. This artillery was almost entirely for defence. Before Elizabethan days (as we have already noted) sea battles were nothing more than hand-to-hand fights; the attacking vessel was laid alongside its enemy, sails were furled, and boarding took place. If, after being swept by spherical shot from the bombards and showers of stones and dice from the mortars and periers, the boarders could carry the waist of the defending ship, they still had to capture the barricaded forecastle and poop, from whose rails a multitude of the smaller ordnance—port-pieces, fowlers, serpentines—were trained upon them and behind whose bulkheads crossbow and harquebuss were plied against them in concealment.
The sixteenth century witnessed the greatest strides in the evolution of sea ordnance. In the Mediterranean the decisive effect of gunfire, proved in the sea fight off Prevesa in the year 1538, was confirmed by the victory of the Christians over the Turks at Lepanto in 1571. In the Atlantic England began her long preparation for securing a sea supremacy and, under the masterful eye of King Henry VIII, adapted more and more powerful guns for service in the royal ships. Of the professional interest which the King took in the development of ordnance there is ample evidence. At the royal word French and Flemish gunfounders were induced to come to England to teach the technique of their craft, and to this puissant prince the Italian savant, Tartaglia, dedicated his classic treatise on the Art of Shooting. England now learnt to found, not only bronze, but cast-iron cannon. “Although,” says Grose, “artillery was used from the time of King Edward III and purchased from abroad by all our successive Kings, it seems extremely strange, that none of our workmen attempted to cast them, till the reign of King Henry VIII, when in 1521, according to Stowe, or 1535 (Camden says), great brass ordnance, as canons and culverins, were first cast in England by one John Owen, they formerly having been made in other countries.” And from Stowe’s Chronicle he quotes the following: “The King minding wars with France, made great preparations and provision, as well of munitions and artillery as also of brass ordnance; amongst which at that time one Peter Bawd, a Frenchman born, a gun-founder or maker of great ordnance, and one other alien, called Peter Van Collen, a gunsmith, both the King’s feedmen, conferred together, devised and caused to be made, certain mortar pieces, being at the mouth from 11 inches, unto 19 inches wide; for the use whereof, the said Peter and Peter caused to be made certain hollow shot of cast yron, stuffed with fire-works, or wild-fire; whereof the bigger sort for the same had screws of yron to receive a match to carry fire kindled, that the fire-work might be set on fire to break in small pieces the same hollow shot, whereof the smallest piece hitting any man, would kill or spoil him. And after the King’s return from Bullen, the said Peter Bawd by himself in the first year of Edward VI did also make certain ordnance of cast yron of diverse sorts and forms, as fawconets, falcons, minions, sakers and other pieces.”[47] The casting of iron guns in Germany has been traced back as far as the fourteenth century.