| Caliber | Field | Ship | Siege | Garrison | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Iron | Bronze | Iron | Bronze | Iron | ||||||
| Old | New | Old | New | Old | New | Old | New | Old | New | |
| 1-1/2-pounder | 6'0" | |||||||||
| 3-pounder | 3'6" | 3'3" | 3'6" | 4'6" | 3'6" | 7'0" | 4'6" | 4'2" | ||
| 4-pounder | 6'0" | |||||||||
| 6-pounder | 4'6" | 4'1" | 8'0" | 4'4" | 7'0" | 4'4" | 8'0" | 6'6" | 5'3" | |
| 9-pounder | 4'8" | 5'0" | 7'0" | 5'0" | 9'0" | 7'0" | 6'0" | |||
| 12-pounder | 5'0" | 5'1" | 9'0" | 5'6" | 9'0" | 5'6" | 9'0" | 6'7" | 8'0" | 6'7" |
| 18-pounder | 5'10" | 6'4" | 9'0" | 6'4" | 9'6" | 8'4" | 9'0" | 7'6" | ||
| 24-pounder | 5'6" | 6'5" | 9'6" | 7'0" | 9'0" | 7'0" | 9'6" | 8'4" | 9'0" | 8'4" |
| 32-pounder | 7'6" | 9'6" | 7'6" | 10'0" | 9'2" | 9'6" | 9'2" | |||
| 36-pounder | 7'10" | 9'6" | ||||||||
| 42-pounder | 9'6" | 8'4" | 10'0" | 8'4" | 9'6" | 10'0" | 10'0" | |||
| 48-pounder | 8'6" | 8'6" | 10'6" | |||||||
In the 1700's cast-iron guns became the principal artillery afloat and ashore, yet cast bronze was superior in withstanding the stresses of firing. Because of its toughness, less metal was needed in a bronze gun than in a cast-iron one, so in spite of the fact that bronze is about 20 percent heavier than iron, the bronze piece was usually the lighter of the two. For "position" guns in permanent fortifications where weight was no disadvantage, iron reigned supreme until the advent of steel guns. But non-rusting bronze was always preferable aboard ship or in seacoast forts.
Müller strongly advocated bronze for ship guns. "Notwithstanding all the precautions that can be taken to make iron Guns of a sufficient strength," he said, "yet accidents will sometimes happen, either by the mismanagement of the sailors, or by frosty weather, which renders iron very brittle." A bronze 24-pounder cost £156, compared with £75 for the iron piece, but the initial saving was offset when the gun wore out. The iron gun was then good for nothing except scrap at a farthing per pound, while the bronze cannon could be recast "as often as you please."
In 1740, Maritz of Switzerland made an outstanding contribution to the technique of ordnance manufacture. Instead of hollow casting (that is, forming the bore by casting the gun around a core), Maritz cast the gun solid, then drilled the bore, thus improving its uniformity. But although the bore might be drilled quite smooth, the outside of a cast-iron gun was always rough. Bronze cannon, however, could be put in the lathes to true up even the exterior. While after 1750 the foundries seldom turned out bronze pieces as ornate as the Renaissance culverins, a few decorations remained and many guns were still personalized with names in raised letters on the gun. Castillo de San Marcos has a 4-pounder "San Marcos," and, indeed, saints' names were not uncommon on Spanish ordnance. Other typical names were El Espanto (The Terror), El Destrozo (The Destroyer), Generoso (Generous), El Toro (The Bull), and El Belicoso (The Quarrelsome One).
In some instances, decoration was useful. The French, for instance, at one time used different shapes of cascabels to denote certain calibers; and even a fancy cascabel shaped like a lion's head was always a handy place for anchoring breeching tackle or maneuvering lines. The dolphins or handles atop bronze guns were never merely ornaments. Usually they were at the balance point of the gun; tackle run through them and hooked to the big tripod or "gin" lifted the cannon from its carriage.
GARRISON AND SHIP GUNS
Cannon for permanent fortifications were of various sizes and calibers, depending upon the terrain that had to be defended. At Castillo de San Marcos, for instance, the strongest armament was on the water front; lighter guns were on the land sector, an area naturally protected by the difficult terrain existing in the colonial period.
Figure 28—EIGHTEENTH CENTURY SPANISH GARRISON GUN.