Artillery Through the Ages

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_Cannon mounted at Castillo de San Marcos in 1683_

Location No. Caliber Class Metal Remarks

In the bastion
of San Agustin
1 40-pounder Cannon Bronze Carriage battered.
1 18-pounder do do New carriage.
2 16-pounder do Iron Old carriages,
wheels bad.
1 12-pounder do Bronze New carriage.
1 12-pounder do Iron do.
1 8-pounder do Bronze Old carriage.
1 7-pounder do Iron Carriage bad.
1 4-pounder do do New carriage.
1 3-pounder do Bronze do.

In the bastion
of San Pablo
1 16-pounder Demicannon Iron Old carriage.
1 10-pounder Demiculverin Bronze do.
2 9-pounder Cannon Iron do.
1 7-pounder Demiculverin Bronze do.
1 7-pounder Cannon Iron Carriage bad.
1 5-pounder do do New carriage.

In the bastion
of San Pedro
1 9-pounder Cannon Iron Old carriage.
2 7-pounder do do Carriage bad.
2 5-pounder do do do.
1 4-pounder do Bronze Old carriage.

In the bastion
of San Carlos
1 10-pounder Cannon Iron Old carriage.
1 5-pounder do do New carriage.
1 5-pounder do Bronze Good carriage.
1 2-pounder do Iron New carriage.

The total number of Castillo guns in service at this date was 27, but
there were close to a dozen unmounted pieces on hand, including a pair
of pedreros. The armament was gradually increased to 70-odd guns as
construction work on the fort made additional space available, and as
other factors warranted more ordnance. Below is a summary of Castillo
armament through the years:

_Armament of Castillo de San Marcos, 1683-1834_

Kind 1683 1706 1740 1763 1765 1812 1834
of gun Iron Iron Iron Iron Iron Iron Iron
Bronze Bronze Bronze Bronze Bronze Bronze Bronze

2-pounder 1 .. .. ** .. .. .. .. .. .. .. .. .. ..
3-pounder .. 1 .. ** 2 3 .. .. .. .. .. .. .. ..
4-pounder 1 1 * ** 5 1 .. .. .. .. 1 .. .. ..
5-pounder 4 1 * ** 15 1 .. .. .. .. .. .. .. ..
6-pounder .. .. * ** 5 .. .. .. .. 1 .. .. 3 ..
7-pounder 4 1 * ** 5 2 .. .. .. .. .. .. .. ..
8-pounder .. 1 * ** 11 1 5 11 .. .. 1 .. .. ..
3-1/2 in.
carronade .. .. * ** .. .. .. .. .. .. 4 .. .. ..
9-pounder 3 .. * ** .. .. .. .. .. .. .. .. .. ..
10-pounder 1 1 * ** .. .. 6 .. .. .. .. .. .. ..
12-pounder 1 1 * ** .. .. 13 .. 7 .. 2 .. .. ..
15-pounder .. .. .. ** 6 .. .. .. .. .. .. .. .. ..
16-pounder 3 .. .. ** .. .. 2 1 .. .. 8 .. .. ..
18-pounder .. 1 .. .. 4 1 7 .. .. .. .. .. 4 ..
24-pounder .. .. .. .. 2 .. 7 .. 32 .. 10 .. 5 ..
33-pounder .. .. .. .. .. 1 .. .. .. .. .. .. .. ..
36-pounder .. .. .. 1 .. .. .. 1 .. .. .. .. .. ..
40-pounder .. 1 .. .. .. .. .. .. .. .. .. .. .. ..
24-pounder
field
howitzer .. .. .. .. .. .. .. .. .. .. .. .. 2 2
6-in.
howitzer .. .. .. .. .. .. .. .. .. .. .. 2 .. 2
8-in.
howitzer .. .. .. .. .. .. .. .. .. 2 .. .. .. ..
Small
mortar .. .. .. .. .. .. .. 18 .. 20 .. .. .. ..
6-in.
mortar .. .. .. .. .. .. .. .. .. .. .. 1 .. 1
10-in.
mortar .. .. .. .. .. .. .. .. .. .. .. .. .. 1
Large
mortar .. .. .. .. .. .. .. 6 .. 1 .. .. .. ..
Stone
mortar 2 .. .. .. .. .. .. .. .. .. .. 3 .. ..

Total 20 9 26 9 55 10 40 37 39 24 26 8 14 6

Grand total 29 35 65 77 63 34 20

* 26 guns from 4- to 10-pounders

** 8 guns from 2- to 16-pounders

This tabulation reflects contemporary conditions quite clearly. The
most serious invasions of Spanish Florida took place during the first
half of the eighteenth century, precisely the time when the Castillo
armament was strongest. While most of the guns were in battery
condition, the table does have some pieces rated only fair and may
also include a few unserviceables. Colonial isolation meant that
ordnance often served longer than the normal 1,200-round life of an
iron piece. A usual failure was the development of cracks around the
vent or in the bore. Sometimes a muzzle blew off. The worst casualties
of the 1702 siege came from the bursting of an iron 16-pounder which
killed four and seriously wounded six men. At that period,
incidentally, culverins were the only guns with the range to reach the
harbor bar some 3,000 yards away.

Although when the Spanish left Florida to Britain in 1763 they took
serviceable cannon with them, two guns at Castillo de San Marcos
National Monument today appear to be seventeenth century Spanish
pieces. Most of the 24- and 32-pounder garrison cannon, however, are
English-founded, after the Armstrong specifications of the 1730's, and
were part of the British armament during the 1760's. Amidst the
general confusion and shipping troubles that attended the British
evacuation in 1784, some ordnance seems to have been left behind, to
remain part of the defenses until the cession to the United States in
1821.

The Castillo also has some interesting United States guns, including a
pair of early 24-pounder iron field howitzers (c. 1777-1812). During
the 1840's the United States modernized Castillo defenses by
constructing a water battery in the moat behind the sea wall. Many of
the guns for that battery are extant, including 8-inch Columbiads,
32-pounder cannon, 8-inch seacoast and garrison howitzers. St.
Augustine's Plaza even boasts a converted 32-pounder rifle.

[Illustration: Figure 29--VAUBAN'S MARINE CARRIAGE (c. 1700).]

Garrison and ship carriages were far different from field, siege, and
howitzer mounts, while mortar beds were in a separate class entirely.
Basic proportions for the carriage were obtained by measuring (1) the
distance from trunnion to base ring of the gun, (2) the diameter of
the base ring, and (3) the diameter of the second reinforce ring. The
result was a quadrilateral figure that served as a key in laying out
the carriage to fit the gun. Cheeks, or side pieces, of the carriage
were a caliber in thickness, so the bigger the gun, the more massive
the mount.

A 24-pounder cheek would be made of timber about 6 inches thick. The
Spaniards often used mahogany. At Jamestown, in the early 1600's,
Capt. John Smith reported the mounting of seven "great pieces of
ordnance upon new carriages of cedar," and the French colonials also
used this material. British specifications in the mid-eighteenth
century called for cheeks and transoms of dry elm, which was very
pliable and not likely to split; but some carriages were made of young
oak, and oak was standard for United States garrison carriages until
it was replaced by wrought-iron after the Civil War.

For a four-wheeled English carriage of 1750, height of the cheek was
4-2/3 diameters of the shot, unless some change in height had to be
made to fit a gun port or embrasure. To prevent cannon from pushing
shutters open when the ship rolled in a storm, lower tier carriages
let the muzzle of the gun, when fully elevated, butt against the sill
over the gun port.

On the eighteenth century Spanish garrison carriage (fig. 28), no
bolts were threaded; all were held either by a key run through a slot
in the foot of the bolt, or by bradding the foot over a decorative
washer. Compared with American mounts of the same type (figs. 30 and
31), the Spanish carriage was considerably more complicated, due
partly to the greater amount of decorative ironwork and partly to the
design of the wooden parts which, with their carefully worked
mortises, required a craftsman's skill. The cheek of the Spanish
carriage was a single great plank. English and American construction
called for a built-up cheek of several planks, cleverly jogged or
mortised together to prevent starting under the strain of firing.

[Illustration: Figure 30--ENGLISH GARRISON CARRIAGE (1756). By
substituting wooden wheels for the cast-iron ones, this carriage
became a standard naval gun carriage.]

Mueller furnished specifications for building truck (four-wheeled)
carriages for 3- to 42-pounders. Aboard ship, of course, the truck
carriage was standard for almost everything except the little swivel
guns and the mortars.

Carriage trucks (wheels), unless they were made of cast iron, had iron
thimbles or bushings driven into the hole of the hub, and to save the
wood of the axletree, the spindle on which the wheel revolved was
partly protected by metal. The British put copper on the _bottom_ of
the spindle; Spanish and French designers put copper on the _top_,
then set iron "axletree bars" into the bottom. These bars strengthened
the axletree and resisted wear at the spindle.

A 24-pounder fore truck was 18 inches in diameter. Rear trucks were 16
inches. The difference in size compensated for the slope in the gun
platform or deck--a slope which helped to check recoil. Aboard ship,
where recoil space was limited, the "kick" of the gun was checked by a
heavy rope called a breeching, shackled to the side of the vessel
(see fig. 11). Ship carriages of the two-or four-wheel type (fig. 31),
were used through the War between the States, and there was no great
change until the advent of automatic recoil mechanisms made a
stationary mount possible.

[Illustration: Figure 31--U. S. NAVAL TRUCK CARRIAGE (1866).]

With garrison carriages, however, changes came much earlier. In 1743,
Fort William on the Georgia coast had a pair of 18-pounders mounted
upon "curious moving Platforms" which were probably similar to the
traversing platforms standardized by Gribeauval in the latter part of
the century. United States forts of the early 1800's used casemate and
barbette carriages (fig. 10) of the Gribeauval type, and the
traversing platforms of these mounts made training (aiming the gun
right or left) comparatively easy.

Training the old truck carriage had been heavy work for the
handspikemen, who also helped to elevate or depress the gun. Maximum
elevation or depression was about 15 deg. each way--about the same as
naval guns used during the Civil War. If one quoin was not enough to
secure proper depression, a block or a second quoin was placed below
the first. But before the gunner depressed a smoothbore below zero
elevation, he had to put either a wad or a grommet over the ball to
keep it from rolling out.

Ship and garrison cannon were not moved around on their carriages. If
the gun had to be taken any distance, it was dismounted and chained
under a sling wagon or on a "block carriage," the big wheels of which
easily rolled over difficult terrain. It was not hard to dismount a
gun: the keys locking the cap squares were removed, and then the gin
was rigged and the gun hoisted clear of the carriage.

A typical garrison or ship cannon could fire any kind of projectile,
but solid shot, hot shot, bombs, grape, and canister were in widest
use. These guns were flat trajectory weapons, with a point-blank range
of about 300 yards. They were effective--that is, fairly accurate--up
to about half a mile, although the maximum range of guns like the
Columbiad of the nineteenth century, when elevation was not restricted
by gun port confines, approached the 4-mile range claimed by the
Spanish for the sixteenth century culverin. The following ranges of
United States ordnance in the 1800's are not far different from
comparable guns of earlier date.

_Ranges of United States smoothbore garrison guns of 1861_

Caliber Elevation Range in yards

18-pounder siege and garrison 5 deg. 0" 1,592
24-pounder siege and garrison 5 deg. 0" 1,901
32-pounder seacoast 5 deg. 0" 1,922
42-pounder seacoast 5 deg. 0" 1,955
8-inch Columbiad 27 deg.30" 4,812
10-inch Columbiad 39 deg.15" 5,654
12-inch Columbiad 39 deg. 0" 5,506

_Ranges of United States naval smoothbores of 1866_

Caliber Point-blank range Elevation Range in yards
in yards
32-pounder of 42 cwt 313 5 deg. 1,756
8-inch of 63 cwt 330 5 deg. 1,770
IX-inch shell gun 350 15 deg. 3,450
X-inch shell gun 340 11 deg. 3,000
XI-inch shell gun 295 15 deg. 2,650
XV-inch shell gun 300 7 deg. 2,100

_Ranges of United States naval rifles in 1866_

Caliber Elevation Range in yards

20-pounder Parrott 15 deg. 4,400
30-pounder Parrott 25 deg. 6,700
100-pounder Parrott 25 deg. 7,180

In accuracy and range the rifle of the 1860's far surpassed the
smoothbores, but such tremendous advances were made in the next few
decades with the introduction of new propellants and steel guns that
the performances of the old rifles no longer seem remarkable. In the
eighteenth century, a 24-pounder smoothbore could develop a muzzle
velocity of about 1,700 feet per second. The 12-inch rifled cannon of
the late 1800's had a muzzle velocity of 2,300 foot-seconds. In 1900,
the Secretary of the Navy proudly reported that the new 12-inch guns
for _Maine_-class battleships produced a muzzle velocity of 2,854
foot-seconds, using an 850-pound projectile and a charge of 360 pounds
of smokeless powder. Such statistics elicit a chuckle from today's
artilleryman.

SIEGE CANNON

Field counterpart of the garrison cannon was the siege gun--the
"battering cannon" of the old days, mounted upon a two-wheeled siege
or "traveling" carriage that could be moved about in field terrain.
Whereas the purpose of the garrison cannon was to destroy the attacker
and his materiel, the siege cannon was intended to destroy the fort.
Calibers ranged from 3- to 42-pounders in eighteenth century English
tables, but the 18- and 24-pounders seem to have been the most widely
used for siege operations.

[Illustration: Figure 32--SPANISH EIGHTEENTH CENTURY SIEGE CARRIAGE.]

The siege carriage closely resembled the field gun carriage, but was
much more massive, as may be seen from these comparative figures drawn
from eighteenth century English specifications:

24-pounder 24-pounder
field carriage siege carriage

9 feet long Length of cheek 13 feet.
4.5 inches Thickness of cheek 5.8 inches.
50 inches Wheel diameter 58 inches.
6x8x68 inches Axletree 7x9x81 inches.

Heavy siege guns were elevated with quoins, and elevation was
restricted to 12 deg. or less, which was about the same as United States
siege carriages permitted in 1861. It was considered ample for these
flat trajectory pieces.

Both field and siege carriages were pulled over long distances by
lifting the trail to a horse-or ox-drawn limber; a hole in the trail
transom seated on an iron bolt or pintle on the two-wheeled limber.
Some late eighteenth century field and siege carriages had a second
pair of trunnion holes a couple of feet back from the regular holes,
and the cannon was shifted to the rear holes where the weight was
better distributed for traveling. The United States siege carriage of
the 1860's had no extra trunnion holes, but a "traveling bed" was
provided where the gun was cradled in position 2 or 3 feet back of its
firing position. A well-drilled gun crew could make the shift very
rapidly, using a lifting jack, a few rollers, blocks, and chocks. When
there was danger of straining or breaking the gun carriage, however,
massive block carriages, sling carts, or wagons were used to carry the
guns.

Sling wagons were of necessity used for transport in siege operations
when the guns were to be mounted on barbette (traversing platform)
carriages (fig. 10). Emplacing the barbette carriage called for
construction of a massive, level subplatform, but it also eliminated
the old need for the gunner to chalk the location of his wheels in
order to return his gun to the proper firing position after each shot.

The Federal sieges of Forts Pulaski and Sumter were highly complicated
engineering operations that involved landing tremendously heavy
ordnance (the 300-pounder Parrott weighed 13 tons) through the surf,
moving the big guns over very difficult terrain and, in some cases,
building roads over the marshes and driving foundation piles for the
gun emplacements.

The heavy caliber Parrotts trained on Fort Sumter were in batteries
from 1,750 to 4,290 yards distant from their target. They were very
accurate, but their endurance was an uncertain factor. The notorious
"Swamp Angel," for instance, burst after 36 rounds.

FIELD CANNON

[Illustration: Figure 33--SPANISH 4-POUNDER FIELD CARRIAGE (c. 1788).
This carriage, designed on the "new method," employed a handscrew
instead of a wedge for elevating the piece, a--The handspike was
inserted through eyebolts in the trail, b--The ammunition locker held
the cartridges.]

The field guns were the mobile pieces that could travel with the army
and be brought quickly into firing position. They were lighter in
weight than any other type of flat trajectory weapon. To achieve this
lightness the designers had not only shortened the guns, but thinned
down the bore walls. In the eighteenth century, calibers ran from the
3- to the 24-pounder, mounted on comparatively light, two-wheeled
carriages. In addition, there was the 1-1/2-pounder (and sometimes the
light 3- or 6-pounder) on a "galloper" carriage--a vehicle with its
trail shaped into shafts for the horse. The elevating-screw mechanism
was early developed for field guns, although the heavier pieces like
the 18- and 24-pounders were still elevated by quoins as late as the
early 1800's.

In the Castillo collection are parts of early United States field
carriages little different from Spanish carriages that held a score of
4-pounders in the long, continuous earthwork parapet surrounding St.
Augustine in the eighteenth century. The Spanish mounts were a little
more complicated in construction than English or American carriages,
but not much. Spanish pyramid-headed nails for securing ironwork were
not far different from the diamond-and rose-headed nails of the
English artificer.

Each piece of hardware on the carriage had its purpose. Gunner's tools
were laid in hooks on the cheeks. There were bolts and rings for the
lines when the gun had to be moved by manpower in the field. On the
trail transom, pintle plates rimmed the hole that went over the pintle
on the limber. Iron reinforced the carriage at weak points or where
the wood was subject to wear. Iron axletrees were common by the late
1700's.

For training the field gun, the crew used a special handspike quite
different from the garrison handspike. It was a long, round staff,
with an iron handle bolted to its head (fig. 33a). The trail transom
of the carriage held two eyebolts, into which the foot of the spike
was inserted. A lug fitted into an offset in the larger eyebolt so
that the spike could not twist. With the handspike socketed in the
eyebolts, lifting the trail and laying the gun was easy.

The single-trail carriage (fig. 13) used so much during the middle
1800's was a remarkable simplification of carriage design. It was also
essential for guns like the Parrott rifles, since the thick reinforce
on the breech of an otherwise slender barrel would not fit the older
twin-trail carriage. The single, solid "stock" or trail eliminated
transoms, for to the sides of the stock itself were bolted short, high
cheeks, humped like a camel to cradle the gun so high that great
latitude in elevation was possible. The elevating screw was threaded
through a nut in the stock, right under the big reinforce of the gun.

While the larger bore siege Parrotts were not noted for long
serviceability, Parrott field rifles had very high endurance. As for
performance, see the following table:

_Ranges of Parrott field rifles (1863)_

Caliber Weight Type of Projectile Elevation Range Smoothbore
of gun projectile weight of same
(pounds) (pounds) caliber

10-pounder 890 Shell 9.75 5 deg. 2,000 3-pounder.
do 9.75 20 deg. 5,000
20-pounder 1,750 do 18.75 5 deg. 2,100 6-pounder.
do 18.75 15 deg. 4,400
30-pounder 4,200 do 29.00 15 deg. 4,800 9-pounder.
do 29.00 25 deg. 6,700
Long shell 101.00 15 deg. 4,790
do 101.00 25 deg. 6,820
Hollow shot 80.00 25 deg. 7,180
do 80.00 35 deg. 8,453

Amazingly enough, these ranges were obtained with about the same
amount of powder used for the smoothbores of similar caliber: the
10-pounder Parrott used only a pound of powder; the 20-pounder used a
two-pound charge; and the 30-pounder, 3-1/4 pounds!

HOWITZERS

The howitzer was invented by the Dutch in the seventeenth century to
throw larger projectiles (usually bombs) than could the field pieces,
in a high trajectory similar to the mortar, but from a lighter and
more mobile weapon. The wide-purpose efficiency of the howitzer was
appreciated almost at once, and it was soon adopted by all European
armies. The weapon owed its mobility to a rugged, two-wheeled carriage
like a field carriage, but with a relatively short trail that
permitted the wide arc of elevation needed for this weapon.

[Illustration: Figure 34--SPANISH 6-INCH HOWITZER (1759-88). This
bronze piece was founded during the reign of Charles III and bears his
shield. a--Dolphin, or handle, b--Bore, c--Powder chamber.]

English howitzers of the 1750's were of three calibers: 5.8-, 8-, and
10-inch, but the 10-incher was so heavy (some 50 inches long and over
3,500 pounds) that it was quickly discarded. Mueller deplored the
superfluous weight of these pieces and developed 6-, 8-, 10, and
13-inch howitzers in which, by a more calculated distribution of the
metal, he achieved much lighter weapons. Mueller's howitzers survived
in the early 6- to 10-inch pieces of United States artillery and one
fine little 24-pounder of the late eighteenth century happens to be
among the armament of Castillo de San Marcos, along with some early
nineteenth century howitzers. The British, incidentally, were the
first to bring this type gun to Florida. None appeared on the Castillo
inventory until the 1760's.

[Illustration: Figure 35--ENGLISH 8-INCH "HOWITZ" CARRIAGE (1756). The
short trail enabled greater latitude in elevating the howitzer.]

In addition to the very light and therefore easily portable mountain
howitzer used for Indian warfare, United States artillery of 1850
included 12-, 24-, and 32-pounder field, 24-pounder and 8-inch siege
and garrison, and the 10-inch seacoast howitzer. The Navy had a
12-pounder heavy and a 24-pounder, to which were added the 12- and
24-pounder Dahlgren rifled howitzers of the Civil War period. Such
guns were often used in landing operations. The following table gives
some typical ranges:

_Ranges of U. S. Howitzers in the 1860's_

Caliber Elevation Range in yards

10-inch seacoast 5 deg. 1,650
8-inch siege 12 deg.30' 2,280
24-pounder naval 5 deg. 1,270
12-pounder heavy naval 5 deg. 1,085
20-pounder Dahlgren rifled 5 deg. 1,960
12-pounder Dahlgren rifled 5 deg. 1,770

[Illustration: Figure 36--ENGLISH MORTAR ON ELEVATING BED (1740).]

From earliest times the usefulness of the mortar as an arm of the
artillery has been clearly recognized. Up until the 1800's the weapon
was usually made of bronze, and many mortars had a fixed elevation of
45 deg., which in the sixteenth century was thought to be the proper
elevation for maximum range of any cannon. In the 1750's Mueller
complained of the stupidity of English artillerists in continuing to
use fixed-elevation mortars, and the Spanish made a _mortero de
plancha_, or "plate" mortar (fig. 37), as late as 1788. Range for such
a fixed-elevation weapon was varied by using more or less powder, as
the case required. But the most useful mortar, of course, had
trunnions and adjustable elevation by means of quoins.

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