PROJECTILE-THROWING ENGINES
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.
[Illustration: PLATE XXX*
Armour of Charles V., from Augsburg or Nuremberg
_A. F. Calvert_]
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.
[Illustration: FIG. 440.--Principle of the balista.]
_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.
[Illustration: PLATE XXXI*
Burgundy Cross Armour of Philip II.
_A. F. Calvert_]
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.
[Illustration: PLATE XXXII*
Gauntlets of Charles V.
_A. F. Calvert_]