"|5'0"| 9'0"| |7'0"| 6'0"|
12 |5'0" |5'1" |9'0"|5'6" | 9'0"|5'6"| 9'0"| 6'7"|8'0"| 6'7"|
18 | |5'10"| |6'4" | 9'0"|6'4"| 9'6"| 8'4"|9'0"| 7'6"|
24 |5'6" |6'5" |9'6"|7'0" | 9'0"|7'0"| 9'6"| 8'4"|9'0"| 8'4"|
32 | | | |7'6" | 9'6"|7'6"|10'0"| 9'2"|9'6"| 9'2"|
36 | | | |7'10"| | | | 9'6"| | |
42 | | |9'6"|8'4" |10'0"|8'4"| 9'6"|10'0"| |10'0"|
48 | | | |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.

Mueller 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 L156, compared with L75
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," an