Chapter X: Part II: Naval Ordnance (2)

Serge is used in all smooth-bores and breech-loading rifles, except for the blank cartridges of smooth-bores, which are of silk.

Silk is used for all muzzle-loading rifles.

Cartridges are always filled by weight and not by measure.

All cartridges are both choked and hooped, the number of hoops depending on the length of the cartridge. These hoops are either of twine or braid, according to the size and weight of cartridge and the stiffness required.

All cartridges are marked in black with the nature of the gun for which they are intended, the weight of powder, and the monogram of the station where they were filled.

Cartridges are packed in magazines, in corrugated brass tanks which are either rectangular or pentagonal.

Cartridges for calibres above 8 inches are not transported about the ship’s decks in passing-boxes, but in zinc cylinders with a lock cover.

PROJECTILES.

The projectiles used are shot, shell, shrapnel, and case-shot.

The Palliser chilled shot is used with the muzzle-loading guns of 7 inches and upward. It is of cast-iron, the head as far as the shoulder being cast in a chill, while the rest is in a sand-mould. This shot is never solid, but a space is left large enough to contain a bursting-charge if desirable. By this means a better casting is obtained. With the larger calibres, the cylindrical part of the shot is reduced slightly in diameter to allow for setting up when the projectile first starts. There are four kinds of shells: the segment, common, double, and Palliser. The segment shells are only used with breech-loaders. This shell consists of a thin cast-iron cylindro-conoidal case lined with cast-iron segments built up in layers and leaving a cylindrical powder-chamber in the centre. The base is closed by a cast-iron disc. It is provided with a thin jacket of alloy, which takes in the rifling and gives the twist to the projectile.

The common shell is the ordinary cast-iron projectile. In addition to its fuse-hole it is provided with a loading-hole opening on the shoulder.

The double shell is similar to the common shell, except that it is nearly four calibres long and its chamber is provided with longitudinal strengthening ribs. It is only used in the 7-inch gun.

The Palliser shell is similar to the Palliser shot, except that it is slightly longer and has a larger chamber. Fuses are never used with the Palliser shot or shell.

The shrapnel consists of two main parts—the cast-iron body and the wooden head. The body is nearly as thick as that of the common shell, and is scored longitudinally in order to permit it to break up easily. The wooden head is covered with a light sheet-iron case which rivets to the body. The bottom of the chamber is the powder-chamber proper, over the mouth of which rests a wrought-iron disc having a hole in the centre, tapped to take a wrought-iron tube. The upper chamber is filled with lead bullets which are set fast with resin. The fuse screws into a hole in the head, and projects into the wrought-iron tube communicating with the powder-chamber. Both the chamber and the tube are filled with powder.

Case-shot are of the ordinary form. Up to the 7-inch calibre the body is made of tin, beyond that it is of tinned sheet-iron. For the smaller calibres the bottom is of tin, for the larger it is a wrought-iron disc. The top is in all cases tinned iron. The contents of the case are packed in clay and sand, and there is an interior lining made up of three loose-fitting wrought-iron segments.

Shot and shell used with muzzle-loading rifles are now provided with a copper disc attached to the base, called a gas-check. This disc is slightly convex to the rear to enable it to spread and stop the windage on firing. It is attached to the projectile by means of a screw-plug and nut. On firing, it is expanded into the rifling and completely stops the windage. It gains a grip on the base of the shell by means of an undercut rim, whilst radial scores on the base prevent it from gaining an independent rotary motion, and enable it to assist in rotating the projectile.

All muzzle-loading projectiles are provided with studs for rotation. They are of gun-metal, swedged into countersunk holes, in two rows. The loading side of all grooves is cut back so as to double the width of the groove at the muzzle, in order to facilitate the insertion of the projectile.

Papier-maché wads are used in front of the heavier projectiles to keep them from slipping forward out of place. These wads are very slightly less than the calibre of the gun, and about an inch in thickness. A hole is bored through the centre, large enough to leave a clear space for the fuse. A short papier-maché tube projects from the forward side of the wad, which serves to attach it to the rammer when loading, and hold it vertical while the charge is going home.

Shell-charges for Palliser projectiles are introduced in serge bags to prevent premature explosions.

FUSES.

Both time and percussion fuses are used in the navy. The time-fuses are the Boxer and the Armstrong; the latter used only with breech-loading segment shell. The percussion fuse is the Pettman.

The Boxer time-fuse has a beech-wood body and is conical in shape. The fuse composition is a vertical column in a centre channel which is not bored entirely through the bottom, a base being left to receive the set-back of the column on firing. Two side channels are bored from the bottom nearly to the top, and are filled with mealed powder. Holes are bored from the outside into these channels one tenth of an inch apart, and the composition burns at the rate of one inch in five seconds, so that each hole represents a half-second. The head of the fuse is closed by a safety-cap, which is removed before loading. The time of burning is set by boring through the desired hole into the composition. The bottom hole is always bored through.

The Armstrong time-fuse is made of gun-metal. A ring of fuse composition similar to that of the old Bormann fuse is pressed in a channel whose outer wall is marked in inches and tenths. This fuse composition is covered by a movable collar which is kept in place by a nut. Attached to this movable collar is a small chamber containing a detonator. When the gun is fired, this detonator ignites the composition at the point at which it is set, and the flame travels around until it meets the magazine, or blowing-chamber, which communicates the flame to the shell-charge.

The Pettman percussion fuse is made up of seven principal parts—the body, top plug, steady plug, detonating ball, cone plug, lead cap, and bottom plug. The top and bottom plugs are set fast; the shock of firing sets back all the other parts, crushing the lead cap over the cone and bottom plugs, which by their shape are all held fast when jammed together. The detonating ball, whose surface is covered with a detonating composition, is carried straight back and prevented from coming in contact with the sides of the chamber by the steady plug. When the projectile strikes, however, the steady plug starts forward and releases the ball, which, coming in contact with the sides of the fuse, explodes the detonating powder and the flame is carried by holes through the lower plugs to the charge.

PRIMERS.

Gun-locks are no longer used in the navy. Guns are fired by means of either the friction or the electric tube. The quill friction-tube is used exclusively for the navy. This tube is of two sizes, the short and the long, the latter being used with the heavy calibres. The quill is driven with mealed powder, and a hole is pierced through the centre. The top and bottom are stopped with shellac putty. In the upper part of the tube an iron-wire friction-bar is inserted, having a sprinkling of detonating composition and mealed powder on one side. The top of the tube is strengthened by a thread woolding and a leather loop, which slip over a pin placed forward of the vent.

The naval electric tube consists of a quill body and a xylonite bottom, the quill being of a diameter to slip completely into the vent. Within this quill are insulated terminals of wire connected by a platinum-silver wire bridge surrounded by priming composition. The whole tube goes into the vent, a stop on the insulating wires preventing it from going too far.

SIGHTS.

All muzzle-loading guns, except turret-guns and boat-guns, have six sights—three hind-sights (two tangent and one centre) and three trunnion-sights. Boat-guns have one centre hind and one fore sight, and turret-guns have turret-sights. All guns except boat-guns have wood scales, and all guns in covered batteries, except turret-guns, have graduated arcs on the pivot-circles.

The tangent-sight is a rectangular steel bar rounded off on two sides, and having a gun-metal head in which slides a gun-metal leaf. The gun-metal leaf slides in a socket, and is provided with a simple clamp-screw. These sights are graduated on the four sides. In general, the forward side is graduated to 10´ from 0 up to 12°. The right side is marked from 100 up to 4000 yards, and for seconds of fuse from 1 to 30—both graduations for common shell with the full charge; the rear side from 100 to 4800 yards for Palliser shot or shell with the battering-charge; the left side from 100 to 4800 yards, and from 1 second to 34 seconds, for common shell with battering-charge.

The centre hind-sight is a hexagonal gun-metal bar with the sliding leaf marked like the tangent-sights, but shorter.

All hind-sights are set at a permanent angle of deflection.

The fore or trunnion sights consist of a pillar and collar of gun-metal, a small steel leaf, and a screw for fixing the leaf. A gun-metal socket is fixed in the gun, and the sight secured in this socket by a double bayonet-joint, so that it may be readily removed or replaced without requiring a special adjustment.

With turret-guns the sights are placed on top of the turret. Each turret is provided with a number of man-holes large enough to admit the head and shoulders. For each man-hole a pair of sights is adjusted, the line of sight being parallel to the axis of the gun. In some turrets, in order to prevent exposure, mirrors are arranged so that these sights may be used by persons in the turret.

The wood scale is a wooden bar used in connection with marks on the rear face of the cascabel. This face is marked from 0 to 3½° for both elevation and depression. The wood scale is a square bar having its four sides marked to yards for different charges. When the gun is placed in position aboard ship, this scale is cut so that its zero and the cascabel zero shall coincide with the guns at level, on an even keel.

The sights for breech-loaders are similar to those of muzzle-loaders, except that what is known as the barrel-headed sliding leaf is used, and there are no centre-sights.

DISTINGUISHING MARKS OF PROJECTILES.

The common shell is known from its carrying a fuse in the point which is cut off for that purpose.

The double shell is known by its disproportion of length to diameter.

The Palliser projectile is known from its sharp point.

The shrapnel is known from the joint which connects the head to the body.

Fragments of a copper disc would denote that Palliser projectiles were used, and a fragment of the head of a Palliser projectile is easily recognizable by the grain of the iron.

PALLISER CONSTRUCTION.

The Palliser construction is entirely applied to the conversion of old cast-iron smooth-bore guns into efficient rifles. In this system the bore of the gun is reamed out to a sufficient diameter to permit the insertion of a coiled wrought-iron tube. This tube is made up of a number of short coiled sections end-welded together. The rear of the tube is planed down, and a jacket (coiled with the spirals opposite in direction to the tube) is shrunk on. The breech end of the tube is closed by a wrought-iron disc screwed into place. The surface of the tube is then turned to a snug but not tight fit in the casing or gun, and is inserted, being held in place by a muzzle screw-collar. A screw is tapped through the chase into the tube to keep it from turning. The old vent is bored through and the gun is submitted to a course of proof-firing with full charges, to expand the tube against the wall of the casing, making a snug fit. A spiral slot is cut around the tube from front to rear, and carried through the cascabel as a tell-tale for the escape of gas in case the tube is split or cracked through at a weld. These guns are extraordinarily long-lived, and have been extensively used by the governments of Great Britain and the United States.

_Palliser Projectiles._ See Pages 208-210.

WHITWORTH CONSTRUCTION.

Whitworth ordnance is used almost exclusively in the Brazilian Navy, and is the regulation type. The Whitworth construction belongs to the all-steel type, and differs in almost every particular from the other types. The guns are both muzzle and breech-loaders. The body of the gun consists of a steel tube reinforced by steel hoops. The tube is cast solid and submitted to a heavy hydraulic pressure while in a molten state, giving the metal as it solidifies a perfectly homogeneous crystallization throughout. This tube is bored completely through, and in the muzzle-loaders the breech end is closed by a steel screw-plug. The hoops are hollow cast and forged on a mandrel, the lengths in the different layers being accurately turned and screwed together; the layers are then put on the gun _cold_ and forced home (from the muzzle end) by hydraulic pressure, the forcing being carefully gauged so as not to crush the metal of the tube.

The breech-loaders are slotted across the rear face in such a manner that the rear face of the block is entirely exposed, thus saving in length of breech of gun. The breech-block is cubical, and is traversed along the upper and lower surfaces by heavy threads set at an angle with the face of the block. These threads travel in heavy male threads in the slot, the system forming the support for the thrust on the block. Attached to the rear face of the block is a weighted crank which revolves a cogged wheel housed in the block and travelling in a rack in the rear of the lower side of the block-seat. In guns of heavy calibre the system is reversed, the crank and wheel housing in the rear of the gun and the rack in the block. By means of this gearing the block is moved transversely, masking and unmasking the bore, the left end of the block being cut for a loading-hole. A stop on the face of the breech locks the block when home and catches it at the proper point when open.

The Whitworth groove is of a peculiar nature, being almost a perfect hexagon, and having an extremely sharp twist of from one turn in 2 feet in the 2-pdr. to one turn in 13 feet in the 9-inch.

The projectiles are cut to fit the grooves, the armor-punching ones being of compressed steel.

THE VAVASSEUR CONSTRUCTION.

Vavasseur ordnance is used considerably in China, and has found some use in other quarters of the world. The gun belongs to the steel type. It consists of a mild-steel oil-tempered tube, reinforced by steel hoops, the hoops being narrow and numerous and shrunk on. The trunnion-hoop is of wrought iron. The gun has, properly speaking, ribs instead of grooves, the grooves being cut in the projectiles. The twist is a constant one.

The gun-carriage possesses a peculiar recoil arrangement, consisting of a heavy screw-shaft traversing the middle of the slide and carrying at its forward end a wrought-iron friction-wheel with a metal strap worked by a lever, by which any desired amount of friction may be applied. Attached to the carriage is a sleeve or clutch grasping the screw-shaft. When the gun recoils, the motion of the sleeve along the shaft causes the latter to revolve, the friction being regulated by the friction-band. For running in and out a large cog-wheel is fixed to the inside of each carriage-bracket, the cogs taking in racks along the sides of the slide. In starting the gun out, the motion of starting slacks the friction-band on the screw-shaft, allowing the gun to run freely; for controlling the motion in a seaway, a small friction-brake on the rear of the slide is used. The carriage is mounted on eccentric rollers, and the movement of throwing them out of or into action ungears or gears the running-out cranks outside of the brackets, so that in recoiling the cranks are not thrown around. The chamber of the Vavasseur gun, as originally constructed, is smaller than the bore, being in this a reversal of the present accepted true principle, and limiting the guns to small charges and low velocities.

FRENCH ORDNANCE.

A = Over all.
B = Bore.
C = Number of Grooves.
-----------------------+--------+---------------+----
NAME, NATURE, AND | | LENGTH. |
CLASSIFICATION. | +-------+-------+
|Calibre.| A | B | C
-----------------------+--------+-------+-------+----
| In. | In. | In. |
French pattern, cast-iron, steel-lined Breech-loaders.
Model of 1870. | | | |
32 cm. | 12.6 | 264 | 244 | 32
27 ” | 10.8 | 212 | 194 | 28
24 ” | 9.46 | 195 | 179 | 24
19 ” | 7.64 | 164 | 151 | 20
16 ” | 6.49 | 146 | 135 | 16
14 ” | 5.46 | 123 | 115 | 14
Model of 1864-67. | | | |
27 ” | 10.8 | 184 | 167 | 5
24 ” | 9.46 | 180 | 165 | 5
19 ” | 7.64 | 150 | 138 | 5
16 ” | 6.49 | 133 | 124 | 3
14 ” | 5.46 | 81 | 73.6 | 3
Bronze Muzzle-loaders. | | | |
12 cm. | 4.78 | 81.4 | 71.5 | 6
4 ” | 3.41 | 37.8 | 31.7 | 6
Hotchkiss Machine-gun. | 1.46 | 51.2 | 29.1 |
Model of 1858-60 Muzzle-loaders.
22 cm. | | | |
16 ” | | | |
14 ” | | | |
-----------------------+--------+-------+-------+----

D = Twist of Rifling.
E = Gun, including Breech-block.
F = Breech-block.
G = Preponderance.
-----------------------+------+----------------+----
NAME, NATURE, AND | | WEIGHT. |
CLASSIFICATION. | +--------+-------+
| D | E | F | G
-----------------------+------+--------+-------+----
| Cal. | Lbs. | Lbs. | Lbs.
French pattern, cast-iron, steel-lined Breech-loaders.
Model of 1870. | | | |
32 cm. | 0/45 | 85,800 | 1,540 | 396
27 ” | 0/45 | 51,040 | 1,100 | 88
24 ” | 0/45 | 34,400 | 726 | 88
19 ” | 0/45 | 17,500 | 352 | 88
16 ” | 0/30 | 12,000 | | 103
14 ” | 0/30 | 5,900 | 176 | 103
Model of 1864-67. | | | |
27 ” | 0/30 | 45,100 | 704 |
24 ” | 0/30 | 31,900 | 567 |
19 ” | 0/30 | 17,610 | 295 |
16 ” | 0/30 | 11,000 | 191 | 330
14 ” | 0/30 | 4,100 | 103 | 165
-----------------------+------+--------+-------+----
Bronze Muzzle-loaders. | | | |
12 cm. | | 1,360 | | 176
4 ” | | 220 | | 33
Hotchkiss Machine-gun. | | 440 | |
-----------------------+------+--------+-------+----
Model of 1858-60 Muzzle-loaders.
22 cm. | | | |
16 ” | | | |
14 ” | | | |
-----------------------+------+--------+-------+----

A = Carriage.
B = Slide.
C = Steel.
D = Chilled.
E = Common.
F = Canister.
G = Bursting Charge Common Shell.
------------------+-------------+-----------------------+--------------
NAME, NATURE, AND | Carriage. | Projectiles. |
CLASSIFICATION. +-------------+-----------------------+--------------
| Weight. | Complete Weight. | Weight.
+------+------+-----+-----+-----+-----+--------------
| A | B | C | D | E | F | G
------------------+------+------+-----+-----+-----+-----+--------------
| Lbs. | Lbs. | Lbs.| Lbs.| Lbs.| Lbs.| Lbs.
French pattern, cast-iron, steel-lined Breech-loaders.
Model of 1870.
32 cm. | | | 770 | 770 |630 | | 37.4
27 ” |10,230|12,960| 475 | 475 |396 | 317 | 24
+------+------+-----+-----+-----+-----+-----
24 ” | 7,304| 8,140| 317 | 317 |264 | 220 | 17
| 5,720| | | | | |
+------+------+-----+-----+-----+-----+-----
| 4,664|11,550| | | | |
19 ” | 4,400| 3,410| 165 | 165 |137.5| 114| 7
+------+------+-----+-----+-----+-----+-----
16 ” | 3,520| 9,460| 99 | 99 | 84 | 69|
14 ” | 2,085| 1,287| | | 46 | 41| 2.4
Model of 1864-67.
27 ” |10,230|12,980| | 475 | 317 | 321| 14.6
+------+------+-----+-----+-----+-----+-----
| | | | | | 211|
24 ” | 5,720| 8,140| | 817 | 220 | 220| 10.3
+------+------+-----+-----+-----+-----+-----
19 ” | 4,400| 3,410| | 165 | 115 | 105| 4.8
+------+------+-----+-----+-----+-----+-----
16 ” | 3,520| 9,460| | | | |
| 2,639| 1,260| | 99 | 69 | 66| 3
+------+------+-----+-----+-----+-----+-----
14 ” | 1,540| 1,100| | | 41 | 27 | 2.1
| | | | | | 39.6|
------------------+------+------+-----+-----+-----+-----+-----
Bronze Muzzle-loaders.
12 cm. | 1,023| | | | 25 | 24.6| 1.1
| 385| | | | | |
+------+------+-----+-----+-----+-----+-----
| 352| | | | | |
4 ” | 319|231 | | | 10 | 10| .17
------------------+------+------+-----+-----+-----+-----+------
Hotchkiss Machine-gun.
Model of 1858-60 Muzzle-loaders.
22 cm. | | | | | | |
16 ” | | | | | | |
14 ” | | | | | | |
------------------+------+------+-----+-----+-----+-----+-----

A = Steel and Chilled Shot.
B = Common Shell.
C = Ordinary.
D = Saluting.
E = Steel.
F = Chilled.
G = Common.
------------------+------------------------+--------------------
NAME, NATURE, AND | POWDER CHARGE. | INITIAL VELOCITY.
CLASSIFICATION. +-----+------+-----+-----+-----+-------+------
| A | B | C | D | E | F | G
------------------+-----+------+-----+-----+-----+-------+------
|Lbs. |Lbs. |Lbs. | Lbs.|Feet.| Feet.| Feet.
French pattern, cast-iron, steel-lined Breech-loaders.
Model of 1870. | | | | | | |
32 cm. |132 |132 | | |1,394| 1,394 | 1,496
27 ” | 92.4| 92.4 |52.8 |19.8 |1,417| 1,417 | 1,542
24 ” | 61.6| 61.6 |35.2 |13.2 |1,443| 1,443 | 1,555
19 ” | 33 | 33 |17.6 | 7.7 |1,456| 1,456 | 1,726
16 ” | 20.9| 20.9 | | |1,575| 1,575 | 1,660
14 ” | | 9 | 9 | 3.3 | | | 1,493
Model of 1864-67.
27 ” | 79.2| 52.8 |52.8 |19.8 | | 1,086 | 1,188
24 ” | 52.8| 35.2 |35.2 |13.2 | | 1,115 | 1,188
19 ” | 27.5| 17.6 |17.6 | 7.7 | | 1,128 | 1,168
16 ” | 16.5| 11 |11 | 5.5 | | 1,132 | 1,197
14 ” | | 4.4 | 4.4 | 4.4 | | | 1,053
------------------+-----+------+-----+-----+-----+-------+------
Bronze Muzzle-loaders.
12 cm. | | 2.2 | 2.2 | 2.2 | | | 1,007
4 ” | | .66| .66| .66| | | 738
Hotchkiss Machine-gun. | .18| | | | | 1,318
------------------+-----+------+-----+-----+-----+-------+------
Model of 1858-60 Muzzle-loaders.
22 cm. | | | | | | |
16 ” | | | | | | |
14 ” | | | | | | |
------------------+-----+------+-----+-----+-----+-------+------

-------------------+------------------------------+-----------------
NAME, NATURE, AND | MUZZLE ENERGY. | PENETRATION.
CLASSIFICATION. +---------+----------+---------+-------+---------
| Steel. | Chilled. |Common. | Steel.| Chilled.
-------------------+---------+----------+---------+-------+---------
|Ft. Tons.| Ft. Tons.|Ft. Tons.| In. | In.
French pattern, cast-iron, steel-lined Breech-loaders.
Model of 1870.
32 cm. | 10,390 | 10,390 |9,730 | 14.5 | 14.5
27 ” | 6,596 | 6,596 |6,506 | 12.5 | 12.5
24 ” | 4,561 | 4,561 |4,414 | 11.1 | 11.1
19 ” | 2,330 | 2,330 |1,828 | 9 | 9
16 ” | 1,698 | 1,698 |1,598 | 8.2 | 8.2
14 ” | | | 712 | |
Model of 1864-67.
27 ” | | 3,871 |3,088 | | 9.6
24 ” | | 2,821 |2,144 | | 8.75
19 ” | | 1,451 |1,081 | | 7.0
16 ” | | 876 | 687 | | 5.87
14 ” | | | 314 | |
-------------------+---------+----------+---------+-------+---------
Bronze Muzzle-loaders.
12 cm. | | | 176 | |
4 ” | | | 39 | |
Hotchkiss Machine-gun. | | | | .94
-------------------+---------+----------+---------+-------+---------
Model of 1858-60 Muzzle-loaders.
22 cm. | | | | |
16 ” | | | | |
14 ” | | | | |
-------------------+---------+----------+---------+-------+---------

GUNS.

Smooth-bore guns are entirely obsolete, except for saluting purposes at dock-yards.

The rifled ordnance consists of the cast-iron breech-loader, model 1870, the cast-iron breech-loader, model 1864-67, the cast-iron muzzle-loader, model 1858-60, the bronze muzzle-loader, the mitrailleuse, and the Hotchkiss machine-gun. A new all-steel pattern is being introduced into the service, whose attachments are quite similar to the model of 1870.

The two models of breech-loaders differ radically in the style of rifling, and although the breech mechanism is the same in principle in both types, it is quite different in detail.

_Breech-Loader, Model 1870._

Guns of this type consist of a cast-iron body strengthened by a steel tube and steel hoops. The steel tube, which is about one quarter of a calibre in thickness, is inserted into the bore from the rear, and is set fast by a heavy male screw-thread worked at its rear end. It extends a short distance forward of the trunnions. The steel hoops are shrunk on over the cast-iron body, and cover all that part occupied by the tube. For the 14-cm. calibre there is but one row of hoops; for the higher calibres two rows breaking joints. The trunnions form a part of the hoop next to the forward one. In all calibres above 16-cm. this trunnion-hoop is thicker than the others, and forms a salient on the surface of the gun.

The bore is rifled on the multigroove system, with an increasing twist of from 0° at the breech to 4° at the muzzle, the direction of the twist being from right to left (contrary to the invariable rule in other countries). The chamber proper is divided into four parts: the shot-chamber, the powder-chamber, the gas-check seat, and the breech-block seat.

The shot-chamber is conical in shape, small end forward, the rifling vanishing at this point in an easy slope. The diameter of this end is the same as that of the bore measured across the grooves. The rear end is joined to the powder-chamber by a second small cone, against which the rear ring of the projectile takes when home.

The powder-chamber is cylindrical, and of a diameter slightly greater than that of the bore.

The gas-check seat is of considerably greater diameter than the powder-chamber. It is conical in shape, small end forward.

The breech-block seat is cylindrical, having a heavy screw-thread around its wall, which is cut into three equal sectors, leaving three blanks of the same width. One of these blanks comes at the bottom of the seat, in order to allow the breech-block to slide back and forth.

The breech mechanism consists of two main parts, the block and the console or bracket, which is hinged to the face of the breech and holds the block when it is withdrawn from its seat.

The breech-block is a steel cylinder having heavy screw-sectors about its surface to correspond with those in the seat. The last turn of screw-thread is left entire in order to relieve the shock of closing the breech. The forward face is made movable in order that when it becomes worn and scored by the action of the powder-gas it may be changed. This face is a steel disc which sets flat against the face of the block, and is of the same diameter. It seats in the face of the block by means of a smaller cylinder or trunnion, and projecting from the rear of this trunnion is a steel rod, which passes completely through the axis of the block and carries the vent. In order to prevent the disc from having any independent motion, a small tenon on its rear face enters a socket in the face of the block. The disc is keyed fast by a small pin which is screwed radially through the block near the middle, the end of the pin taking in a score cut in the vent-rod. A small catch, projecting from the rear lower side of the block, holds the console in place when the breech is closed. The rear face of the block is provided with two parallel handles screwed to it, to assist in moving it, and a long crank-handle between them for revolving the block. At the end of this crank-handle there is a slight projection made to receive the blows of any instrument that may be used to drive the block around when it works stiffly. Along the two lower blanks of the block slots are cut, in which traverse small projections of the console to hold the block steady. About the middle of the lower screw-sector a small hole is cut into which a small stop springs when the block is withdrawn to its limit on the console. The vent is provided with a copper bush at its forward end and a steel one at its rear.

The console is semi-cylindrical, and is hinged to the face of the breech so that when the breech-block is withdrawn it may be swung to the right and unmask the bore. It is provided with a spring stop and two small projections taking in the block, which limit the movement of the latter and hold it steady when resting on the console.

Two small pins, screwed into the face of the breech, limit the arc of movement of the crank-handle, one at the vertical point and the other 60° to the right.

A small stop attached to the face of the breech holds the crank-handle fast when the breech is closed. This stop allows the handle to pass in closing, but must be raised by hand in opening.

The gas-check is of copper, and is a fixture in its seat. It is a ring in reality, the centre being cut out to permit the passage of the charge through it in loading; the edge is turned up, forming a cup, the outer part being conical to fit the seat. The bend of the rim is quite thick, and a gutter is cut around it in order to make the powder-gas seal the joint properly. The bottom of this ring is provided with three concentric grooves to break the force of the gas that may escape through the joints. When the breech is closed the face of the block presses directly on the gas-check, and a copper ring is countersunk in the face of the block which forms the contact with the check. This ring has grooves to correspond with the grooves on the back of the gas-check.

The vent is horizontal, and is situated in the axis of the breech-block. Its outer end is formed in double-cone shape (throughout the steel bush), the small ends of the cone being joined. Percussion primers are used in connection with a spring gun-lock. (See Primers.)

_Breech-Loader, Model 1864-67._

These guns are hooped like the model of 1870, but are not tubed.

The vent is pierced vertically near the bottom of the powder-chamber, instead of being in the breech-block.

The grooves are of the pattern known as the “basket-handle,” for mechanical fit projectiles (see French Groove, English Ordnance), having an increasing twist of from 0° to 6°. The 14-cm. and 16-cm. guns have three grooves, the others five. The width of the grooves is the same throughout the length of the bore, being cut back on the loading side near the powder-chamber to facilitate loading. The depth of the groove, however, diminishes towards the muzzle in order to pinch the studs and steady the projectile. At the powder-chamber and running forward for a short distance in the centre of each band is a supplementary groove, in which travel the rear studs of the projectiles, which are made so small as to easily sheer off. These secondary grooves prevent the projectile from being pushed too far into the bore. With the 19-cm. gun, the supplementary groove is made by cutting back the loading side of the regular groove. There is no shot-chamber proper.

The powder-chamber is cylindrical, of the same diameter as that of the bore across the grooves. The bottom groove is produced through the powder-chamber, to serve as a directing groove for the projectile in loading.

In rear of the powder-chamber there are two gas-check seats, conical in shape, with the small diameter forward. The rear and larger one is intended for service in case of accident to the other.

The breech-plug seat is similar to the model 1870.

The breech-closing mechanism consists of two main parts like that of the model 1870, the breech-plug and the console or bracket.

The breech-plug differs from the model 1870 in being lighter, by having the interior cut away as much as possible consistent with strength. It has two movable faces or discs to correspond with the two gas-check seats. These discs are secured to the face of the plug in a similar manner to the model 1870, except that the disc in this case is allowed to revolve freely. The gas-check is carried on the face of the disc instead of being a fixture of the gun.

It is quite similar to the model 1870, except that the hole in the centre is smaller and serves to secure it to the face of the disc. The centre of the disc being slightly raised carries two ears which receive the inner edge of the gas-check and centre it. Over these a solid-headed nut screws, which fixes the gas-check and makes a tight joint. The gas-check is made of steel.

The console is similar to the model 1870.

_Muzzle-Loader, Model 1858-60._

These guns are hooped, but have no tubes. The trunnions are cast with the body of the gun, the hoops not coming so far forward. The vent is vertical near the bottom of the powder-chamber, like the model 1864.

The grooves are of the “basket-handle” type, three in number, with an increasing twist of from 0° to 6°. These grooves, near the chamber, are cut back and prolonged to form seats for the rear studs.

All guns of this model are converted from old smooth-bores.

_Bronze Muzzle-Loader._

These guns are of the ordinary bronze type. The 23-pdr. (canon de 12) has six common grooves having a _regular_ twist from _left_ to _right_. The bottom groove is narrowed on the loading side near the powder-chamber in order to force the studs into close contact with the driving side. The 8-pdr. (canon de 4) has six grooves with a regular twist similar to the 23-pdr.

The vent is pierced vertically near the bottom of the powder-chamber.

_The Mitrailleuse._

The exterior of the mitrailleuse has the appearance of a bronze cannon. This case encloses 25 rifled tubes brazed together. The rear part of the cannon presents a vertical cavity, very large and nearly rectangular in shape. This cavity is called the cage, and is intended to receive the breech-block and firing mechanism. The breech-block is a cubical block containing prolongations of the 25 barrels which serve as chambers for the cartridges. When loaded, this block drops into the forward part of the cage. The lock mechanism is a box containing 25 firing-pins, arranged with guides and springs on the ordinary system. This box is movable longitudinally by the motion of a breech-screw, which also sets up the breech-block when in place. The motion forward of this box retracts the firing-pins, which are then held until released in rapid succession by a turn of the crank. After firing, the breech-screw is backed, the block taken out and a loaded one is put in its place, the screw is set up retracting the locks, and the piece is ready for firing again.

_Hotchkiss Machine-Gun._

(See United States Ordnance.) This gun is an American invention, but was first introduced into the French Navy.

CARRIAGES.

Gun-carriages in the French Navy are classified as follows:

Slide-carriages for heavy broadside-guns.

Turret-carriages and revolving-slide carriages for heavy guns.

Directing-bar carriages for broadside-guns.

Four-truck and rear-chock carriages for broadside-guns.

Gun-boat carriages for bronze guns.

Boat-carriages for bronze guns.

Mountain carriages for bronze guns.

Mitrailleuse saddle or fork for machine-guns.

_Slide-Carriage for 27-cm. and 24-cm. Guns._

The rails of the slide are of heavy double =T= iron, connected by =T= and plate iron transoms. The slide rests on a pair of conical rollers, with concentric axles forward and a double pair of rear rollers (concentric) at the rear. The forward pair of the rear rollers and the front rollers travel on smooth tracks, while the rear pair of rollers are pinions working in a rack on deck. The slide is traversed by tackles, except in fine pointing, when levers are shipped on the rear rollers and the fine traversing is done by heaving on them. A pawl working on the rear rollers secures the slide in any desired position. The recoil is checked by friction compressors. There are eight iron compressor-bars on each side of the slide, just inside of the rails, resting on the front and rear transoms. On top of the front transom is a heavy iron dumb-sheave, which receives the bight of a rope breeching. The carriage is of the ordinary form of double plate, mounted on rollers, the forward pair being in permanent action and the rear pair on eccentric axles. Tackles are used for running out and in. The compressor-plates are nine in number on each side, suspended on an axle. The outer plates are heavier than the others. The ones next to the brackets are backed by steel disc-springs. Rocking levers working in screw-threads on the axle press against the inner plates. The levers are worked by a ratchet-lever on the exterior right side, this lever being provided with a trip for throwing it down automatically in firing. Railway buffers are placed at the rear of the slide to act in case of over-recoil. The elevating-gear consists of a flat-linked chain passing underneath and supporting the breech of the gun. The ends of the chain wind about axles in the carriage-brackets, the axles being revolved by endless-screw gearing. Levers for turning this gearing ship outside the brackets. In elevating or depressing, it is necessary to turn the gearing alike on both sides in order to keep the centre link, which is marked, in its place under the breech. In elevating, the gearing must be worked slowly in order to allow the breech to follow down by its preponderance. With the 24-cm. gun, the compressor-plates, 12 in number, are all in the centre instead of being at the sides.

_Slide-Carriage for 19-cm. Gun._

The fixtures for the slide and carriage differ in several particulars from the heavier ones. The slide travels on four _pairs_ of rollers, the rear rollers of the rear pairs being cogged for fine pointing as in the heavier ones. The slide rests on iron pillars with screw-threads at the upper extremities, the lower ones resting on the axles between the rollers, forming a pair. The threaded top has a capstan-head, so that, by turning, the front or rear of the slide may be elevated or depressed. These rollers are also arranged for transporting the slide from port to port. For this they may be turned to run in the desired direction, similar to the principle of chair-rollers (casters). Clamps are provided to hold them in the desired position.

The carriage has only one in-tackle. The rocking-lever compressor is changed to the ordinary bow-compressor. (See English Ordnance, Compressor for wooden-slide carriages.)

_Turret-Carriage and Slide for Heavy Guns._[7]

The turret-slide, instead of being provided with rollers for traversing, is mounted on a centre-pivoting turn-table. The turret itself is fixed, the gun firing over it “en barbette.” The turn-table is mounted on sixteen conical rollers, and is revolved by means of a fixed rack, to which gears a pinion worked by a crank attachment on the slide. This attachment consists of a horizontal axle revolving in bearings through the rear of the slide-plates, having a crank at each end and a chain-wheel in the middle. An endless chain transmits the motion to gearing at the forward end of the slide, which connects with the rack on the floor of the turret. A locking arrangement holds the turn-table in the desired direction. The slide resting on its supports rises to a much greater height than with broadside-carriages, and is provided with a short stairway from the turn-table to the slide-top. The carriage is similar to the ones heretofore described, except that extra gearing is applied to the elevating apparatus to enable it to be reached by the men standing on the turn-table. Chain-gear similar to Scott’s in and out gear is used with the carriage. Instead of a movable stirrup used to catch the chain, the upper part passes through a slit in the rear transom of the carriage, so that when the rear trucks are thrown in action teeth in it catch the chain. The same style of compressor is used as is found with the 24-cm. carriage previously described, except for the 19 cm. gun, which has the ordinary cramp-compressor.

[7] See plate Part IV. French Barbette Turret.

_Revolving-Slide Carriage._

The slide is a centre-pivot resting on a circular track and on four rollers. It is traversed by a crank revolving gearing which works in a circular rack around the outside of the roller-circle. The carriage is similar to the ordinary type, except that it is much higher, in order to allow a greater angle of depression to the gun. Instead of in and out tackles, a runner is used which passes over a windlass fixed on the rear slide-transom. This runner throws the rear trucks in action, and then, according to its lead, runs the gun in or out. The elevating-gear for the 16-cm. gun consists of a heavy cross-bar underneath the breech, having sleeves at the extremities which clasp heavy upright screws. By revolving these screws, the bar is carried up or down. The elevating-gear for the 14-cm. gun is the old-fashioned telescopic elevating-screw.

_Directing-Bar Carriage._

The carriage proper is of the ordinary rear-chock or Marsilly type, which when run out for firing is lifted from the deck on a slide or chariot, so that it may be easily and quickly trained. The chariot consists of a broad, short front-piece, mounted on two rollers; projecting forward from it is a pivot-flap which secures by a pivot-bolt just underneath the port, the rollers being canted for traversing about the pivot. Projecting to the rear from this front-piece is a tongue made of =T= iron, which is supported at its rear end on two trucks which are canted like the forward ones for traversing. When the carriage is run in, its rear end comes flush with the end of this tongue, and the forward trucks rest on the deck. In running out, however, two small rollers on the axle, inside of the brackets, catch on and mount two inclined planes which slope back from the top rear of the chariot, thus lifting the carriage completely from the deck. A breeching is used with this carriage, its bight going around a =B= block on the front of the chariot. There is also a friction compressor at the rear of the brackets, the compressor plates taking against the sides of the =T= iron, which are filled out with wood for that purpose. The forward edge of the =B= block serves as a hurter in running out. In all other respects the carriage is similar to the ordinary broadside rear-chock carriage. It is used on upper decks of large ships for light guns.

_Four-Truck Carriage and Rear-Chock Carriage._

These are of the general type of old-fashioned wooden carriages.

_Gun-Boat Carriages and Boat-Carriages._

These carriages are of the old-fashioned type. The former is the slide pattern, its only peculiarity being that its forward and rear rollers can be revolved for transportation on a vertical pivot. The carriage has no rear trucks.

The carriage is provided with holding-down clips, and the recoil is checked by a breeching whose ends are made fast to the brackets, the bight passing around a bollard on the forward transom of the slide.

_Mountain-Carriage._

The mountain-carriage is similar to the English field-carriage except the elevating-gear, which consists of a plain elevating-screw to which a hand-wheel and pinion gear.

_Mitrailleuse Saddle._

This consists of a pillar whose lower end ships in a socket in the ship’s rail, and whose upper end branches into a fork to support the trunnions. A longitudinal support projects from the pillar, which holds a pivoted arm by means of a clamp. This gives a quick motion for elevating or depressing. The end of the pivoted arm holds an ordinary elevating-screw for slow motion.

_Hotchkiss Saddle._ See United States Gun-Carriages.

GUNPOWDER.

The gunpowder used in the French service is classified according to the size of grain.

_Wetteren powder_, named from the place of manufacture in Belgium, is a large-grained cubical powder used in guns of the model 1870.

_Ripault powder_, named from its place of manufacture in France, is an ordinary-sized cannon powder used in all guns, except the above.

_Hunting powder_ is a small-grained, highly-glazed powder used in revolver cartridges.

_B powder_, of a slightly larger grain than the hunting, is used in Chassepot rifle cartridges.

_Musket powder_ is used in the manufacture of primers, fuses, and signals.

CARTRIDGES.

Cartridge-bags are made either of parchment or serge. For the smaller calibres they are of parchment.

Each cartridge is marked in black with the calibre of the gun for which it is intended, the weight of charge, monogram of the place where it was filled, and date of filling.

Cartridges are kept aboard ship in brass or copper tanks of various forms having water-tight covers.

PROJECTILES.

The projectiles used in the French Navy are shot, shell and case-shot. There are two kinds of shot, cylindrical and ogivo-cylindrical, corresponding to the shape of the head; the cylindrical being used only in the calibres above 19 cm. They are all steel. The ogivo-cylindrical shot are used in all calibres above 14 cm., and are either of steel or chilled cast-iron. Shell are of cast-iron, and are similar in shape to the ogival shot.

These projectiles are differently mounted for the different models. For the model 1870 the mounting consists of a forward ring of zinc or cast-iron just back of the shoulder of the shell, slightly smaller than the diameter of the bore across the lands. Its object is simply to keep the forward end of the projectile centred. A rear ring of copper, of a diameter slightly greater than that of the bore across the grooves. This ring brings up in its seat in the shot-chamber, and on firing the bands are scored and rotate the projectile. Around the surface of this ring are two or three grooves, cut to receive the metal displaced by the lands on firing. These projectiles carry at their base a light wire grommet to facilitate handling them.

For the model 1864-67 the projectiles are provided with studs, there being two rows. The forward studs take in the grooves and give the twist to the projectile; the rear ones hold the base of the projectile centred, and according to the calibre of the piece they travel in the grooves or on the lands. For the heavy projectiles, where the rear studs travel on the lands, there are provided three small intermediate studs which bring up in false grooves provided for the purpose, keeping the projectile from going too far forward in the bore when loading. These studs are sheared off on firing. The studs are made either of zinc or bronze. Projectiles for the bronze muzzle-loaders are similar to the model 1864.

Case-shot are of the ordinary type, and have neither studs nor belts.

Sea-weed wads are used with all projectiles except those of the model 1870. These are used in order that the powder-charge may act with a more gradual effect on the projectile at the start. Placed between the charge and the projectile, their rapid compression gives room for the powder to expand and burn more slowly at the first instant.

FUSES.

Percussion fuses are used in all shell except the 25-pdr. and 8-pdr. boat-guns, which use time-fuses.

The percussion fuse consists of a hollow cylindrical bronze body having a solid conical head. At the bottom of the cylinder is screwed a copper firing-pin. The centre of the cylinder is occupied by a brass plunger carrying a charge of hunting powder. The forward end of this plunger carries a wooden plug which is hollow and filled with detonating composition. The plunger is held in position by two iron pins upon which the base rests, and two leaden stops through the wall of the fuse entering the shell of the plunger. These stops are not broken by the start of the projectile, but by its shock on striking an object. The bottom of the fuse, being covered by shellac-paper, is blown away by the charge of powder in the plunger, and the flame is communicated to the charge.

The time-fuse for boat-guns consists of a brass body having two longitudinal chambers for fuse-composition columns of different times of burning. For the 23-pdr. the times correspond to 1500 and 3000 metres; for the 8-pdr. they correspond to 1100 and 2200 metres. The longer column is always uncapped on loading. The different times are distinguishable by the difference in the caps. That for the long time is of wire; for the short time it is of leather covered with a red wafer.

PRIMERS.

The primers are of two kinds, percussion and friction. The former seal the vent entirely on firing, and are only used in guns having vents through the breech-block (Model 1870). Friction primers are used in all guns having vertical vents.

The percussion primer consists of a body of brass or copper, slightly conical and having a solid head. Into this body screws a small steel anvil carrying an ordinary percussion-cap, which, when the anvil is screwed home, bears against the primer-head. The remainder of the body is filled with fine hunting powder, and the bottom is closed by a shellacked wafer.

The friction primer consists of two quill tubes, the lower and larger one being filled with fine musket powder, the bottom being sealed with wax. The upper is filled with fulminating composition, and has passing through its centre a brass friction-wire corrugated along its length. The exterior of the wire is formed in a loop for hooking on the firing laniard. The upper part of the primer is closed by a block of wood forming a fairleader for the friction-wire. A small independent loop is attached to the head of the primer, by which it may be withdrawn from the vent without touching the friction-wire.

SIGHTS.

The sights used in the French Navy are all side-sights, and for the most part the tangent-sights are inclined at a permanent angle.

The front-sights are conical in shape, and are screwed into the rim-bases.

The tangent-sights are square in section, working in boxes screwed to the face of the breech. They are graduated to full and half cable-lengths (200 and 100 metres). As a rule, guns are sighted on the left side, although provision is made for a right tangent and front sight. Sights are graduated on the left side for shell and on the right for shot, the graduations being all carried across the rear face. In general there is a short and a long sight, the long one being used for distances greater than 30 cables (6000 metres).

ACCESSORIES.

The loading-plate is a plate which attaches to the breech of the gun when the breech-block is open; along the bottom of this plate is a groove which forms a prolongation of the bottom groove of the gun (not applicable to model 1870); the projectile being hoisted to the level of the bore is landed on this plate, and is then in position to be rammed home. For small projectiles this plate serves as a shell-bearer for transporting projectiles, being provided with side handles.

The shell is brought to the loading-plate on covered decks by means of a tackle appended to a roller working on a traveller. The projectile being hoisted from the deck is pushed along on the traveller to the plate. In turrets the projectile is hoisted and swung by means of a davit.

The passing-box for the cartridge is made of leather with an ordinary close leather cover.

The rammer and sponge are of the old-fashioned type.

In calibres of a nature above 16-cm. a leather guard is always used in loading, to cover the gas-check and prevent injury from shocks in loading.