At Havana, Cuba, in the early days, there was an abundance of round
stones lying around, put there by Mother Nature. Artillerists at
Havana never lacked projectiles. Stone balls, cheap to manufacture,
relatively light and therefore well suited to the feeble construction
of early ordnance, were in general use for large caliber cannon in the
fourteenth century. There were experiments along other lines such as
those at Tournay in the 1330's with long, pointed projectiles.
Lead-coated stones were fairly popular, and solid lead balls were used
in some small pieces, but the stone ball was more or less standard.
Cast-iron shot had been introduced by 1400, and, with the improvement
of cannon during that century, iron shot gradually replaced stone. By
the end of the 1500's stone survived for use only in the pedreros,
murtherers, and other relics of the earlier period. Iron shot for the
smoothbore was a solid, round shot, cast in fairly accurate molds; the
mold marks that invariably show on all cannonballs were of small
importance, for the ball did not fit the bore tightly. After casting,
shot were checked with a ring gauge (fig. 41)--a hoop through which
each ball had to pass. The Spanish term for this tool is very
descriptive: _pasabala_, "ball-passer."
Shot was used mainly in the flat-trajectory cannon. The small caliber
guns fired nothing but shot, for small sizes of the other type
projectiles were not effective. Shot was the prescription when the
situation called for "great accuracy, at very long range," and
penetration. Fired at ships, a shot was capable of breaching the
planks (at 100-yard range a 24-pounder shot would penetrate 4-1/2 feet
of "sound and hard" oak). With a fair aim at the waterline, a gunner
could sink or seriously damage a vessel with a few rounds. On ironclad
targets like the _Monitor_ and _Merrimac_, however, round shot did
little more than bounce; it took the long, armor-piercing rifle
projectile to force the development of the tremendously thick plate of
modern times.
[Illustration: Figure 41--EIGHTEENTH CENTURY PROJECTILES. (Not to
scale.)]
Round shot was very useful for knocking out enemy batteries. The
gunner put his cannon on the flank of the hostile guns and used
ricochet firing so that the ball, just clearing the defense wall,
would bounce among the enemy guns, wound the crews, and break the gun
carriages. In the destruction of fort walls, shot was essential. After
dismounting the enemy pieces, the siege guns moved close enough to
batter down the walls. The procedure was not as haphazard as it
sounds. Cannon were brought as close as possible to the target, and
the gunner literally cut out a low section with gunfire so that the
wall above tumbled down into the moat and made a ramp right up to the
breach. Firing at the upper part of the wall defeated its own purpose,
for the rubble brought down only protected the foundation area, and
the breach was so high that assault troops had to use ladders.
The most effective bombardment of Castillo de San Marcos occurred
during the 1740 siege, and shot did the most damage. The heaviest
English siege cannon were 18-pounders, over 1,000 yards from the fort.
Spanish Engineer Pedro Ruiz de Olano reported that the balls did not
penetrate the massive main walls more than a foot and a half, but the
parapets, being only 3 feet thick, suffered considerable damage. Some
of the old parapets, Engineer Ruiz said, "have been demolished, and
the new ones have suffered very much owing to their recent
construction." (He meant that the new mortar had not sufficiently
hardened.) Ruiz was not deceived about what would happen if hostile
batteries were able to get closer; in such case, he thought, the enemy
"will no doubt succeed in destroying the parapets and dismounting the
guns."
Variations of round shot were bar shot and chain shot (fig. 41), two
or more projectiles linked together for simultaneous firing. Bar shot
appears in a Castillo inventory of 1706, and like chain shot, was for
specialized work like cutting a ship's rigging. There is one
apocryphal tale, however, about an experiment with chain shot as
anti-personnel missiles: instead of charging a single cannon with the
two balls, two guns were used, side by side. The ball in one gun was
chained to the ball in the other. The projectiles were to fly forth,
stretching the long chain between them, mowing down a sizeable segment
of the enemy. Instead, the chain wrapped the gun crews in a murderous
embrace; one gun had fired late.