No evidence is extant respecting the inventor of the first machine for missile throwing, but we know that they have existed from the earliest ages, and have been used by all the great nations of antiquity. Under the Greeks and Romans, but especially the former, they attained a remarkable degree of excellence, and many accounts of their extraordinary efficiency have come down to us. The Romans took their ideas from the Greeks as a basis to work upon; among their best authorities Vitruvius may be classed. The principles involved in these engines were not altogether lost, but descended to the mediÆval ages, and probably during that period more elaborate, powerful, and gigantic machines were constructed than at any previous time.

The complicated methods by which a fortress was captured or a town carried during the Middle Ages are not generally known, and the means adopted at the present time are as a general rule credited with being the outcome of the skill and science of the past few centuries. This, however, will not bear the test of investigation, for we find that almost every device has had its prototype in past ages, and nearly every idea has been forestalled. It comes almost with a shock to some, and produces feelings of incredulity, to be told that huge missiles vieing in destructive effect with the modern shell, and as a rule many times larger, were sent with unerring aim into the heart of a besieged town, levelling houses to the ground and dealing destruction far and wide. The idea of a siege in mediÆval times is generally that of a tree to batter down a door, archers to shoot down the defenders on the walls, desperate charges of cavalry against sallies of the garrison, and forlorn hopes of men carrying scaling-ladders with which to surmount the walls. These are, however, only a few concomitants of the complicated methods by which a siege was accomplished.

The Greeks and Romans constructed their engines upon the principle of the bow, whereas the mediÆval engineers adopted that of the sling. The latter was by far the more clumsy of the two, but probably just as effective. Had the methods by which the Greeks were enabled to construct their splendid engines been handed down, the possibility is that mediÆval machines would have been far less cumbersome and much smaller. Probably the greatest living authority upon projectile-throwing machines is Sir Ralph Payne-Gallwey, Bart., who has constructed models of ancient and mediÆval machines with most successful results. He says, “My engines are by no means perfect in their mechanism, and are always liable to give way under the strain of working. One reason of this is that all modern engines of the kind require to be worked to their utmost capacity, i.e. to the verge of their breaking-point, to obtain from them results that at all equal those of their prototypes. The ancient engines did their work easily and well within their strength. Although my largest catapult will throw a stone to a great distance it cannot throw one of nearly the weight it should be able to do, considering the size of its frame, skein of cord, and mechanism. In this respect it is decidedly inferior to the ancient engine.”[1] The author of the above has, however, been able to construct a catapult which throws a stone of 8 lbs. to a distance of between four hundred and fifty and five hundred yards.

The Catapult.—The “Tormentum” of the Romans was a generic name for military engines, and so named from the twisting of the hair, thongs, sinews, &c., of which the propelling mechanism was made. What were the exact materials used, and in what proportions, is entirely unknown, and probably the knowledge did not extend beyond a century or so after the fall of the empire. There can be no doubt but that the sinews of animals played an important part in the construction of the skein. The method of making the catapult was as follows, omitting unnecessary details. A quadrangular wooden frame of great strength was fitted near one end with the skein, which was made in the form of a circle and of very considerable thickness, the rubber tyre of a large motor-car wheel approximating both in size and shape. This was folded into two parallel straight lines and passed through holes in the frame on either side, where a simple mechanism grasped it which could revolve the ends, cogs preventing them from turning in any direction but that desired. Between the parallel parts of the skein the end of the arm was placed, and by twisting the ends of the skein the arm was made to press with considerable force against a horizontal beam supported by uprights at the two sides. The arm was provided with a hollow in the upper part for holding the stone. If now the arm were drawn back by means of levers, ropes, and pulleys, the distortion upon the skein was increased enormously, and if when loaded with a projectile the arm were released, it sprang back against the beam with great velocity and force, throwing the stone to a distance during the action. This propulsive force was considerably augmented in some machines by the addition of a sling to the end of the arm, which practically lengthened the arm and consequently hurled the projectile to a greater distance. Ancient writers assert that the range was sometimes as much as from seven hundred to eight hundred yards.

The Balista.—This machine was used by the Romans for discharging the Falarica or ponderous spear, which had an iron head of over a foot in length at one end, with a ball of lead at the other end, and was at times used to carry incendiary material. It was projected upon the same principle as the stone in the catapult, namely by means of twisted skeins, but in the case of the balista two were in use. They were fitted vertically in a frame open to the front: an arm was passed through each skein, and when the skeins were twisted, the arms sought to diverge from one another. A rope acted like the string of a bow, and was wound back by a suitable apparatus, thus tending to draw the arms to a parallel position; upon its release the falarica was propelled in exactly the same manner as an arrow is discharged. It rested in a directing hollow trough until the trigger was pulled. These heavy missiles travelled at times to a distance of between three hundred and four hundred yards and it will thus be seen that practically the two ends of a bow are used for the propulsive force. The balista could also be used for discharging stones if required by a simple alteration of the bow-string, and the addition of another trough for directing the missile.

The Trebuchet.—The Trebuchet was a mediÆval weapon derived from the classical engines of previous ages, but depending entirely upon the principle of the sling in contradistinction to that of torsion. It was a gigantic arm of wood, lengthened considerably by a sling; the arm was pivoted near one end remote from the sling, and this beam being actuated by the fall of an extremely heavy weight caused it to describe the quarter of a circle and discharge the missile. It superseded the catapult, chiefly for the reason that the making of the skeins of the latter had become a lost art, and also that a trebuchet could be quickly constructed on the spot required with materials generally found ready to hand, whereas the catapult necessarily had to be transported. Consequently trebuchets were invariably dismantled after a siege and not carried from place to place, the ponderous nature of the machine presenting an obstacle to such a course. There is no doubt that the addition of the sling was an idea obtained from the East at a very early date, as a MS. of the thirteenth century contains a representation showing it. In Add. MS. 10,292, British Museum, a trebuchet is shown in use against a castle which is being attacked by knights of the Ailette Period clad in banded mail. This shows the sling affixed to the arm, but no comparison of size is possible, as the machine is shown smaller than a horse, and the horse is nearly the size of the castle. In Roy. MS. 16, G. VI., dating from c. 1330, two trebuchets are shown in action against a castle. They are much out of drawing, as the arm bearing the counterpoise of one is actually shown longer than the arm bearing the sling, whereas it was probably only a small fraction of the length. Hewitt quotes from a work written by Gilles Colonne (d. 1316) for his pupil, Philip the Fair of France, in which he says, “Of perriers (a general name for stone-projecting machines) there are four kinds, and in all these machines there is a beam which is raised and lowered by means of a counterpoise, a sling being attached to the end of the beam to discharge the stone. Sometimes the counterpoise is not sufficient, and then they attach ropes to it in order to move the beam. The counterpoise may either be fixed or movable, or both at once. In the fixed counterpoise a box is fastened to the end of the beam, and filled with stones or sand or any heavy body. These machines cast their missiles with most exactness, because the weight acts in a uniform manner. Their aim is so sure that one may, so to say, hit a needle. If the gyn carries too far it may be drawn back or loaded with a heavier stone; if the contrary, then it must be advanced or a smaller stone supplied. Others of these machines have a movable counterpoise attached to the beam, turning upon an axis. The third kind has two weights, one fixed to the beam and the other movable round it; by this means it throws with more exactness. The fourth sort, in lieu of weights attached to the beam, has a number of ropes, and is discharged by a number of men pulling simultaneously at the cords. This last kind does not cast such large stones as the others, but it has the advantage that it may be more rapidly loaded and discharged than they. In using the perriers by night it is necessary to attach a lighted body to the projectile; by this means one may discover the force of the machine and regulate the weights of the stone accordingly.” This very valuable description of four varieties of the trebuchet at such an early date gives us an idea of the state of perfection to which they had then arrived, and from other sources may be obtained particulars relating to the size and weight of the missiles employed. They were not always of stone, but barrels of Greek fire, pitch, naphtha, and other inflammable substance were used; also occasionally the bodies of dead horses and other animals, often in a state of decomposition, barrels of offensive or putrid matter, and other missiles of a similar nature designed to cause pestilence, were thrown into towns or fortresses when the defence was obstinately prolonged. In the account left to us by Guillaume des Ormes of Carcassone in 1240, we read: “Afterwards they set up a mangonel before our barbican, when we lost no time in opposing to it from within an excellent Turkish petrary, which played upon the mangonel and those about it; so that, when they essayed to cast upon us, and saw the beam of our petrary in motion, they fled, utterly abandoning their mangonel. And in that place they made ditches and palisades, yet as often as we discharged our petrary we drove them from it.” At the siege of Bedford Castle in 1224, the garrison of which were followers of Faukes de BreautÉ, a leader of mercenaries in the time of King John, seven mangonels were in use in the besieging force. Matthew Paris mentions the terrible effects of the trebuchets in 1246 at the siege of the castle of Cappacio, when seven well-ordered machines discharged day and night such an uninterrupted storm of missiles upon the ill-fated fortress that it was battered into a helpless condition, and had perforce to surrender. He also states that in 1253 the Gascons hurled stones and darts of such wonderful size that many of them were carried into England to be exhibited as curiosities. In the defence of castles the garrison naturally set up missile-throwing weapons, and these were as a rule built upon the ground within the encircling walls, and threw their projectiles high in the air over the battlements into the enemy’s camp. Smaller ones were also built upon the walls and towers. Where large towns were besieged it was no unusual thing to have from one to three hundred projectile-throwing engines in action. The mangonel, petrary, mangonella, biblia, and many other names used by mediÆval writers, all refer to the trebuchet and its many modifications.

Various machines were invented during the Middle Ages, in which the principle of propulsion was the steel bow mounted upon a frame partaking of the nature of the arbalest. These bows were at times of considerable size, and threw javelins, spears, and weapons of a similar nature. Being mounted upon wheels, they served all the purposes fulfilled by modern field artillery. In the same category may be mentioned one which threw one or two stones at a single discharge: it consisted of a vertical spring of steel which was pulled backwards by ropes and pulleys, and upon being released threw one missile from a sling attached to its extremity and another from a cup fixed to the steel.