Navies of the world

by Edward W. Very

English Ordnance.

• A = Over all.
• B = Rifled Bore.
• C = Powder Chamber.
• D = Number of Grooves.

Name, Nature, and Classification.	Length.			D
	A	B	C
	In.	In.	In.
17-inch, 100-ton	392	308	55	27
Muzzle-loading, built-up Guns. Woolwich pattern.
Armor-piercing.
16-inch, 80-ton	321	231.5	56.5
12.5-in., 38-ton	230	170.5	27.5	9
12-inch, 35-ton	195	135	27.5	9
12-inch, 25-ton	182.5	127	18	9
11-inch, 25-ton	180	119	26	9
10-inch, 18-ton	180	119	26.5	7
9-inch, 12-ton	156	104	21	6
8-inch, 9-ton	144	99.5	18.5	4
7-inch, 90-cwt	131	95.5	15.5	3
7-inch, 6½-ton	133	95.5	15.5	3
64-pdr., 64-cwt., shell	118	90	7.5	3
Boat.
9-pdr., 8-cwt	72	59.8	3.7	3
9-pdr., 6-cwt	61	49.3	3.7	3
7 pdr., 200-lb., steel	41	34	2	3
64-pdr., 71-cwt., converted	122.7	96.27	7	3
Breech-loaders. Armstrong pattern.
Shell.
7-inch, 82 cwt.	126	83.5	16	76
40-pdr., 32-cwt.	126	92.87	13.5	56
40-pdr., 35-cwt.	127	92.87	13.5	56
20-pdr., 15-cwt	72	43.12	11	44
20-pdr., 18-cwt	72	43.12	11	44
Boat.
9-pdr., 6-cwt.	68	45.5	7	38
6-pdr., 8-cwt.	66	46	7	32
12-pdr., 8-cwt.	78	52.87	8.5	38

• E = Twist of Rifling.
• F = Weight of Guns.
• G = Preponderance.

Name, Nature, and Classification.	E	F	G
	Calib.	Lbs.	Lbs.
17-inch, 100-ton	0/40	229,000	8,960
Muzzle-loading, built-up Guns. Woolwich pattern.
Armor-piercing.
16-inch, 80-ton		179,200
12.5-in., 38-ton	0/35	85,120
12-inch, 35-ton	0/35	78,400	120
12-inch, 25-ton	100/50	56,000	616
11-inch, 25-ton	0/35	56,000	168
10-inch, 18-ton	100/40	40,300	952
9-inch, 12-ton	0/45	26,900	560
8-inch, 9-ton	0/40	20,100	448
7-inch, 90-cwt	35	10,100	560
7-inch, 6½-ton	35	14,500	336
64-pdr., 64-cwt., shell	40	7,160	336
Boat.
9-pdr., 8-cwt	30	896	7
9-pdr., 6-cwt	30	672	29.5
7 pdr., 200-lb., steel	20	200	5
64-pdr., 71-cwt., converted	40	7,950	714
Breech-loaders. Armstrong pattern.
Shell.
7-inch, 82 cwt.	37	9,184	776
40-pdr., 32-cwt.	36.5	3,584	607
40-pdr., 35-cwt.	36.5	3,920	532
20-pdr., 15-cwt.	38	1,680	108
20-pdr., 18-cwt.	38	1,456	164
Boat.
9-pdr., 6-cwt.	38	672	82
6-pdr., 8-cwt.	30	886	55
12-pdr., 8-cwt.	38	896	199

• A = Carriages.
• B = Slide.
• C = Height of Axis of Bore above Deck.

Name, Nature, and Classification.	Carriages.
	Weight.		C
	A	B
	Lbs.	Lbs.	In.
17-inch, 100-ton		Turret
Muzzle-loading, built-up Guns. Woolwich pattern.
Armor-piercing.
16-inch, 80-ton		Turret
12.5-in., 38-ton		Turret
12-inch, 35-ton	25,000	Turret	45
12-inch, 25-ton	11,800	19,712	60
	23,100	Turret
11-inch, 25-ton	21,120	Turret	49
	10,700	18,500
10-inch, 18-ton	21,000	Turret	49
	8,940	8,680
9-inch, 12-ton	4,800	7,400	44
8-inch, 9-ton	4,780	6,710	44
7-inch, 90-cwt	2,700	3,900	41
7-inch, 6½-ton	3,500	4,700	41
64-pdr., 64-cwt., shell	1,430	2,600	41.5
Boat.
9-pdr., 8-cwt.	532	356	41.5
9-pdr., 6-cwt.	532	336
7-pdr., 200-lb., steel	112	252
64-pdr., 71-cwt., converted	1,600	2,700
Breech-loaders. Armstrong pattern.
Shell.
7-inch, 82-cwt.	1,760	2,796	42.5
40-pdr., 32-cwt.	1,595	1,425	42
40-pdr., 35-cwt.	1,595	1,425	42
20-pdr., 15-cwt.	616	977	29
20-pdr., 13-cwt.	616	977	29
Boat.
9-pdr., 6-cwt.	298	504
6-pdr., 3-cwt.	560
12-pdr., 8-cwt.	364	336

• D = Chilled.
• E = Common.
• F = Shrapnel.
• G = Burster for Chilled.
• H = Burster for Common.

Name, Nature, and Classification.	Projectiles.
	Entire Weight.			Weight.
	D	E	F	G	H
	Lbs.	Lbs.	Lbs.	Lbs.	Lbs.
17-inch, 100-ton	2,000			11.25
Muzzle-loading, built-up Guns. Woolwich pattern.
Armor-piercing.
16-inch, 80-ton	1,700			9.9
12.5-in., 38-ton	800	843		14	43
12-inch, 35-ton	700	615	612	6.5	40
12-inch, 25-ton	600	497	497	6.9	37.7
11-inch, 25-ton	535	536		5.5	29.7
10-inch, 18-ton	400	398	404	4.5	20.25
9-inch, 12-ton	250	250	255	2.5	19
8-inch, 9-ton	180	182	180	2.5	14.5
7-inch, 90-cwt.	115	117	116		8.75
7-inch, 6½-ton	115	117	116		8.75
64-pdr., 64-cwt., shell		64	66		7.2
Boat.
9-pdr., 8-cwt.		9	9.75		.5
9-pdr., 6-cwt.		9	9.75		.5
7-pdr., 200-lb., steel		7	7.5		.4
64-pdr., 71-cwt., converted		64	66 Segment shell.		7.2
Breech-loaders. Armstrong pattern.
Shell.
7-inch, 82-cwt.		90	102		7.6
40-pdr., 32-cwt.		38	40		.25
40-pdr., 35-cwt.		38	40		.25
20-pdr., 15-cwt.		20.5	20		1.2
20-pdr., 13-cwt.		20.5	20		1.2
Boat.
9-pdr., 6-cwt.		9.5	8.5		.4
6-pdr., 3-cwt.		6	5.5
12-pdr., 8-cwt.		11.25	11		.5

• A = For Steel and Chilled Shot.
• B = For Common Shell.
• C = Ordinary Firing.
• D = Saluting.
• E = Chilled Shot.
• F = Common Shell.

Name, Nature, and Classification.	Powder Charge.				Initial Velocity.
	A	B	C	D	E	F
	Lbs.	Lbs.	Lbs.	Lbs.	Ft.	Ft.
17-inch, 100-ton	440				1,590
Muzzle-loading, built-up Guns. Woolwich pattern.
Armor-piercing.
16-inch, 80-ton	370				1,520
12.5-in., 83-ton	130				1,451
12-inch, 35-ton	110				1,300
12-inch, 25-ton	85	67	55		1,180
11-inch, 25-ton	85	70	60		1,315
10-inch, 18-ton	70	60	44		1,364
9-inch, 12-ton	50	43	30	15	1,420
8-inch, 9-ton	35	30	20	12	1,413
7-inch, 90-cwt	30	22	14	10	1,525
7-inch, 6½-ton	30	22	14	10		1,250
64-pdr., 64-cwt		10	10	6		1,383
Boat.
9-pdr., 8-cwt.		1.75	1.75	1.5		1,380
9-pdr., 6-cwt.		1.5	1.5	1		1,390
7-pdr., 200-lb., steel		.75	.75	.25		968
64-pdr., 71-cwt., converted		8	8	6		1,230
Breech-loaders. Armstrong pattern.
Shell.
7-inch, 82 cwt.		11	11	7		1,165
40-pdr., 32-cwt.		5	5	3		1,180
40-pdr., 35-cwt.		5	5	3		1,180
20-pdr., 15-cwt.		2.5	2.5	1.5		1,000
20-pdr., 13-cwt.		2.5	2.5	1.5		1,000
Boat.
9-pdr., 6-cwt.		1.1	1.1	1		1,035
6-pdr., 3-cwt.		.75	.75	.7		1,046
12-pdr., 8-cwt.		1.5	1.5	1		1,239

Name, Nature, and Classification.	Muzzle Energy.		Penetration. (Iron.)		Remarks.
	Chilled Shot.	Common Shell.	At 500 Yards.	At 1000 Yards.
	Foot Tons.	Foot Tons.	In.	In.
17-inch, 100-ton	37,700
Muzzle-loading, built-up Guns. Woolwich pattern.
Armor-piercing.
16-inch, 80-ton	27,213		27.5	26.4
12.5-in., 38-ton	11,676		18.7	17.7	Woolwich groove.  Increasing twist.
12-inch, 35-ton	8,200		15.4	14.6
12-inch, 25-ton	7,030		13.9	13.1
11 inch, 25-ton	6,415		13.8	13.1
10-inch, 18-ton	5,160		12.7	12
9-inch, 12-ton	3,496		10.4	9.6
8-inch, 9-ton	2,492		9.8	9.5
7-inch, 90-cwt.	1,855		8.8	8.6	Woolwich groove.
7-inch, 6½-ton		1,246	7.7	7.1	Uniform twist
64-pdr., 64-cwt shell		848			Shunt groove.  Uniform twist.
Boat.
9-pdr., 8-cwt.		528			Modern French groove.
9-pdr., 6-cwt.		120			Uniform twist.
7-pdr., 200-lb., steel		45.5			French groove.  Uniform twist.
64-pdr., 71-cwt., converted		670			Plain groove.  Uniform twist.
Breech-loaders. Armstrong pattern.
Steel.
7-inch, 82-cwt.		847
40-pdr., 32-cwt.		378			Armstrong  multigroove. Uniform  twist.
40-pdr., 35-cwt.		378
20-pdr., 15-cwt.		142
20-pdr., 13-cwt.		142
Steel.
9-pdr., 6-cwt.		64
6-pdr., 3-cwt.		45.6
12-pdr., 8-cwt.		117

Guns.

The old cast and wrought iron smooth-bore guns are now obsolete, and only found in service at dock-yards for saluting and experiment, and forming the broadside batteries of some of the training ships.

The rifled ordnance consists of the Woolwich muzzle-loader, the Palliser converted muzzle-loader, the Armstrong breech-loader, and the Gatling machine-gun.

7-inch Mark III.

The Woolwich type is subdivided into marks or patterns of each calibre corresponding to the gradual improvements in manufacture. Mark I. is in most cases the original Armstrong pattern, in which the jacket is composed of a large number of small coils or bands. In the other marks the number of the coils is decreased, whilst each one is increased in size.

10-inch Mark I.

The Palliser converted type is confined to the 64-pdr. calibre.

The Armstrong breech-loader is no longer manufactured, but there are many guns of this type in service. These breech-loaders were originally of two types, known as the screw and the wedge gun. The latter was designed especially for naval use, but it has been entirely withdrawn from service, leaving only the screw type. It is not improbable that another type of breech-loaders will eventually find its way into service, having a breech-closing arrangement similar to the French type in principle.

64-pdr.

SECTION OF GROOVE FULL SIZE.

French Groove.

French Modified Groove.

Woolwich Groove.

Plain Groove.

Various systems of grooves will be found in these guns, corresponding to different stages of development. In the 7-pdr. the French groove is used, having sharp angles, the loading side being at a sharper pitch than the driving. In the 9-pdrs. appears the modified French groove, in which the angles are rounded off and the loading side is at right angles to the driving side. In the 64-pdr. converted gun the plain groove is used. This groove is almost rectangular, the driving side being canted but little. In the 64-pdr. of 64 cwt. the shunt groove is used. This is a double groove, one half being deeper than the other, the rear end of the groove having a shunt by which the studs are turned into the shallow half. The 7-inch muzzle-loaders have the Woolwich groove with a uniform twist. This groove is the final modification of the original French groove. The higher calibres up to the 16-inch gun have the Woolwich groove with an increasing twist. The 16-inch calibre will have the plain multigroove, or the groove ordinarily used for expanding projectiles. The breech-loaders have the Armstrong multigroove, a groove which in section is not unlike a saw-tooth.

7-pdr. Steel R. M. L. 200 lbs.

Introduced into service in 1873. Made of a single block of steel, having no swell at the muzzle, but a small dispart patch into which the fore sight screws. Copper vent bouch. The sight is a plain, centre hind sight set at a permanent angle of deflection of 3°. It seats in a hole bored in the metal of the gun, having a simple clamp-screw to hold it in position. Two sight-bars are used with the gun, one graduated to 6° and the other to 12°, the graduations on both being for intervals of 3´. This gun may be distinguished from the 9-pdr. by the slope at the junction of the reinforce and chase, which is gradual.

9-pdr. Wrought Iron R. M. L. 6 and 8 cwt.

Introduced into service in 1871 and 1873. It consists of two parts—a toughened steel tube, and a jacket composed of two single coils and a trunnion-ring welded together. The cascabel is cut out of the solid end of the steel tube, and is recessed to receive the head of the elevating screw, which is fastened to it by a bolt and keep-pin. The 6 cwt. and 8 cwt. guns differ only in length and weight, the latter being 10½ inches longer. The 7-pdr. and the 9-pdr. are of the same calibre, but the same projectiles cannot be used in both, as the twist is different and the studs on the 7-pdr. projectile are much wider than those of the 9-pdr. The arrangement of the sights is the same for both guns. It is easily distinguished by the abrupt step at the forward end of the jacket.

9-pdr.

64-pdr. Wrought Iron R. M. L. 64 cwt.

There are three marks or patterns of this gun. Mark I. was adopted in 1864 to replace the Armstrong wedge breech-loaders. It belongs to the Armstrong type of construction, and consists of a wrought-iron coiled A tube, a forged breech-piece, a trunnion-ring, several outer coiled tubes, and a muzzle-ring. The A tube being bored all the way through, the joints at the bottom of the bore were closed by means of a heavy copper gas-check. The calibre is 6.3 inches, in order to permit firing 32-pdr. round shot from it. The greater part of these guns have been retubed with a steel A tube. In these, the plain groove is found, whilst the iron-tubed ones have the shunt groove. This gun is easily recognizable by its raised trunnion-ring and also by the combination of the stepped breech with the muzzle-ring. Mark II. was adopted in 1866. It is made up of a coiled wrought-iron A tube, double at the chase, a forged breech-piece, a breech-coil composed of a double coil and trunnion-hoop welded together, a coil in front of the trunnions, and a cascabel block. The end of the bore of the A tube is reduced and forms a gomer chamber. These guns may be recognized either by the shunt rifling combined with the Woolwich form of gun or by the letter B marked on the left trunnion. Mark III. is made up of a solid-ended steel A tube, a breech-coil made up of a triple coil, trunnion-ring and coil in front of the trunnions welded together, and a forged cascabel block. These guns are similar in appearance to the 7-inch, but the sea-service guns of this mark have iron A tubes, and may be recognized by the shunt rifling.

64-pdr. R. M. L. 71 cwt. (Converted.)

64-pdr. Converted.

Adopted in 1864. This gun is the old cast-iron 8-inch gun, which is bored out and tubed on the Palliser plan. The tube is coiled and double at the rear, and, being through bored, the bottom joints are closed by a screw cup. After insertion the tube is held in place by a muzzle screw-collar and a pin tapped through the casing just forward of the trunnions. The gun is easily recognized from its old-fashioned shape.

7-inch R. M. L. 6½ tons and 90 cwt.

Adopted in 1865. There are three patterns of the 6½-ton guns, the first being of the old Armstrong construction, recognizable by its soda-water bottle shape. The other two marks are of the improved construction. The 90-cwt. gun was adopted in 1874 for use in the armament of unarmored vessels. It is similar to the Mark III. 6½-ton gun, except that it is lighter, the outside being turned down to get the required lightness. These guns are very similar in build and exterior appearance to the 64-pdr.

8-inch R. M. L. 9 Tons.

Introduced in 1866. There are three marks of this gun, similar to the 7-inch patterns. The only way in which the 8-inch can be distinguished from the 7-inch without measuring the diameter of the bore is by the fact of its having four grooves in place of three.

9-inch R. M. L. 12 Tons.

Introduced in 1865. There are five marks of this gun, the first one being of the old Armstrong construction, and the others of the Woolwich developments. The distinctive mark of this calibre is the grooving, there being six grooves.

10-inch R. M. L. 18 Tons.

Introduced in 1868. There are two patterns of this gun, both of the Woolwich design. The distinguishing marks are the nine grooves.

11-inch R. M. L. 25 Tons.

Introduced in 1867. There are two patterns of this calibre, both Woolwich. But few of them are used in the navy. This calibre cannot be distinguished from the 12-inch, except by measurement.

12-inch R. M. L. 25 Tons and 35 Tons.

The 25-ton gun was introduced in 1864. There are two patterns, the first built on the old Armstrong pattern, there being but four in service. The second mark is Woolwich. The 35-ton gun was introduced in 1871. There is but one mark of this gun corresponding to the Woolwich.

12-inch Mark I.

12½-inch R. M. L. 38 Tons.

Introduced in 1875. There is but one mark of this calibre, and it exactly resembles the 35-ton 12-inch.

16-inch R. M. L. 80 Tons.

Introduced in 1878. There is but one mark of this calibre. These guns have a chamber one inch greater in diameter than the bore, and the form of rifling is that used with expanding projectiles, being multigroove with shallow grooves. The construction corresponds to the latest development of the Woolwich pattern.

16-inch.

Armstrong Construction.

The first type of rifled guns introduced into the English naval service was the Armstrong, for both breech and muzzle loaders. Fabrication of original breech-loader ceased in 1864, but many of this type still remain in service. The original construction of the muzzle-loader was modified in 1864, but the general type and principles were preserved and are still used. The present type of modified Armstrong construction is used by many foreign services, and the 100-ton gun has been introduced in the English service. The modified Armstrong breech-loading system for the 100-ton gun has been adopted in Italy.

The grooves of the breech-loader (original) are saw-toothed in shape, vanishing at the shot-chamber for use with a lead-coated projectile.

Armstrong Groove for Breech-Loader.

Armstrong Shunt Groove for Muzzle-Loaders.

Armstrong 100-ton Gun (Improved Construction).

The grooves of the muzzle-loader (original) are of the shunt or double type, being cut to the full depth for the entire length and one half the width of the groove. The other half of the width is cut on an incline from the muzzle towards the chamber, this half being the driving side. The loading edge of the groove near the bottom is cut at a sharp angle so as to throw the studs of the projectile against the driving edges of the groove, and give it a close bearing. In coming out the studs ride up the incline of the driving side and are pinched, centring the projectile. This groove is now obsolete. The groove of the improved muzzle and breech-loaders is the plain groove.

BREECH-LOADING GUNS
(ORIGINAL).

7-inch B. L. R. 82 cwt.

This calibre has been totally withdrawn from service, and has been replaced by the muzzle-loader. The body of the gun consists of an A tube, a breech-piece and B tube, a trunnion-ring and six coils. A vertical slot pierces the gun at the base of the chamber, into which fits a block called the vent-piece. This block is quite light and is easily lifted out or replaced by means of handles. The forward face of the block fits the rear of the chamber, and the escape of gas is prevented by means of a tin-cup gas-check. This vent-piece is held in position when in the gun by a block termed a breech-screw. This block is provided with a full screw-thread, and works longitudinally, the forward end of the block seating against the back of the vent-piece. This breech-screw is provided with a handle for turning, the handle being weighted at the end, and having a lost-motion movement by which the block may be driven close home when screwed up. The vent is bored in the vent-piece, piercing it vertically to the centre, and then turning at right angles. The breech-screw is hollow, the hole being of slightly less diameter than the powder-chamber. When the vent-piece is out, the gun is cleaned and loaded through the breech-screw.

Armstrong Breech-Loader.

Vent-Piece.

Breech-Screw.

40-pdr. B. L. R. 32 and 35 cwt.

The same general type as the larger calibre. In this and smaller calibres there is no separate gas-check, the joint consisting of two bevelled copper facings, one on the vent-piece and the other in the powder-chamber, which form a close contact and seal the joint by expansion.

20-pdr. B. L. R., 15 and 13 cwt.;
12-pdr. B. L. R., 8 cwt.;
9-pdr. B. L. R., 6 cwt.;
6-pdr. B. L. R., 3 cwt.

Same construction as the 40-pdr., except that the coils are fewer.

Modified Breech-Loaders.

Although these guns are not yet introduced into service, they probably will be. The construction is the same in principle for the body of the gun as in the old breech-loaders, with slight modifications. The breech mechanism is almost identical with the French, the modifications being in the gas-check, which is of the general Broadwell type.

MUZZLE-LOADERS
(ORIGINAL).

Armstrong 10-inch Muzzle-Loader
(Original Construction).

These guns consist of a steel solid-ended tube, reinforced by a number of coils connected by hook-joints. The coils are of wrought-iron bars, rolled into hollow cylinders and the turns welded in order to give a circumferential direction to the grain. Over the breech and powder-chamber a forged breech-piece fits, the grain of the iron running longitudinally. The base of the A tube is supported by a solid wrought-iron piece screwing into the forged breech-piece. A narrow spiral gutter is cut around the A tube throughout its length, and carried out at the cascabel screw-thread. By means of this, in case that the steel tube gets cracked through, the leakage of gas gives warning by blowing out at the breech. Some of these guns (7-inch) have the shunt groove, and the later ones the Woolwich groove.

Modified.

The modified construction consists in abolishing the forged breech-piece, giving the steel tube a greater thickness over the powder-chamber, and decreasing the number of coils, whilst their thickness is increased individually. The guns are also given a greatly increased length of bore, and the powder-chamber is enlarged in diameter to permit the insertion of a heavier charge. Plain grooves.

At present the Elswick Company is engaged in supplying the Italian Government with breech-loading 100-ton guns. The breech-block is of the French type, and arrangements are made for moving the block as well as loading by hydraulic or steam power. The 100-ton gun has no carriage proper, its trunnions resting in heavy blocks on the fixed slide, being connected in rear with hydraulic recoil pistons which are themselves connected in such a manner as to equalize the strain of recoil. The movements of running out and in and loading are all performed by hydraulic power. The vent of the 100-ton gun is axial both in the breech and muzzle loader.

Armstrong Projectiles ([see page 209]).
Armstrong Fuze ([see page 211]).

Armstrong Breech Mechanism and Rotating Belt.

The points of peculiarity of the Armstrong breech mechanism are: 1st. The face of the breech-block is made slightly convex so that the gas-check springs back when the pressure comes on it, throwing the edge outwards, and making a wedged joint. This comes free again the moment that the block is started. 2d. The rear of the shaft holding the gas-check in place is held by a spiral spring, so that in turning the block to lock it the gas-check is not revolved in its seat.

CARRIAGES.

Naval gun carriages and slides, as a rule, are built of plate-iron, although many of the wooden ones are still retained in service for the lighter calibres. The lighter carriages are worked by tackles, and the heavy ones by gearing. Breechings are no longer used with slide carriages, the recoil being checked by friction compressors or hydraulic recoil cylinders and buffers.

Wooden carriages are furnished for all smooth-bores and breech-loading rifles, and for 64-pdr. muzzle-loaders. Iron carriages may be furnished for these guns, but wooden ones are never furnished for others.

The wooden standing carriage is the old-fashioned four-truck one. The wooden rear-chock carriage is similar to what is known elsewhere as the Marsilly. Breechings are rove through holes in these carriages, and are not attached to the guns. The wooden slide-carriages and their slides are of the ordinary old-fashioned type. The compressor for these carriages consists on each bracket of the carriage of two iron plates with hinged pieces on their lower ends. They are suspended on iron bolts passing through the bracket so that their lower ends hang down and overlap the side of the slide. Through the upper ends of the plates and the bracket an iron screw and lever passes, whose motion separates or approaches the pieces, allowing them to release or grip the slide. Some slide-carriages are provided with hydraulic recoil cylinders.

Iron Field-Carriage.

This carriage consists of two ¼-inch plate-iron brackets recessed to receive the axle-tree. These plates are strengthened by angle-irons riveted along the upper edge on the outer side from the trunnion-holes to the point. The brackets are lightened as much as possible by having pieces cut out of them. A front transom of plate-iron, having angle-irons riveted to it each side to connect it with the brackets; a similar transom about half way down the brackets; an iron trail-plate and axle-tree, and wooden wheels. The carriage makes a load for a mule, and the wheels another load. The elevating-gear consists of an iron stool-bed formed in front to hook loosely over a cross-bar, while the rear end, provided with two small studs, rests in racks riveted to the brackets. This is for getting rapid elevations. For fine sighting a sliding quoin is fitted to the stool-bed by clips, and is worked by a hand-wheel. Check-ropes are applied to the trail-eye and lashed to the wheels in firing. The Gatling gun is provided with a curved ratchet projecting down from the bottom of the gun-case, giving elevations by means of a hand-wheel and pinion.

7-pdr. Field-Carriage.

Iron Boat-Carriage.

9-pdr. Boat-Carriage.

The boat-carriage is made up of two ⅝-inch plate brackets, having narrow stiffening pieces along the front and upper edges. The brackets are riveted to a bottom plate by angle-irons on the outer sides, and are connected in front by a transom of plate riveted to angle-irons, and in rear by another transom. It has two outside holding-down clips on each side. The elevating-screw admits of 10° elevation and 2° depression. The slide consists of two sides of girder-iron, 6½ inches deep, and are joined by a connecting plate, three bottom plates, and a rear transom. These bottom plates have metal friction-plates attached beneath them. The centre as well as the front is fitted with a pivot-bolt. The transporting axle bolts beneath the slide. The hydraulic buffer lies upon the centre and rear transoms, to each of which it is secured by a band. This buffer is nothing more than the ordinary type of long cylinder and piston.[3] The cylinder is nearly filled with oil through a hole in the upper rear part. In case it is desired to empty the cylinder, there is a hole for the purpose in the lower forward end. Holes of a certain diameter are bored through the piston, and the recoil is checked in proportion to the resistance of the oil in passing through these holes. The cylinder not being quite full leaves an air-cushion to ease the strain. The piston-rod is secured to the carriage, and a slight vertical play is allowed in its fastenings to prevent the jump of the gun from bending it.

Carriage for Light Upper-Deck Guns.

Slide for Light Upper-Deck Guns.

The carriage consists of two ½-inch plate brackets connected by a bottom plate and transom. This carriage has no rollers. It is fitted with the elevating hand-wheel, pinion, and ratchet in use with the heavier calibre.[4] The toothed ratchet bolts to the side of the breech of the gun. The toothed edge of the ratchet gears to a pinion, while the back is supported by a friction-roller attached to the bracket. The pinion being inside the bracket connects with a hand-wheel on the outside, which is held by a friction-brake. The peculiarity of the slide is that it slopes to the front at an angle of 10°. It is provided with a hydraulic recoil buffer ([see Boat-Carriage]), and also with plate compressors. There are two rubber buffers at the front of the slide to catch the gun in running out, and an in-tackle is fitted underneath the slide. A pivot-flap projects from the front of the slide, the pivot-bolt being close to the gun-port.

Carriage and Slide for 7-inch M. L. R.

7-inch Carriage.

The carriage is a single-plate one, having two brackets, two transoms, and a bottom plate assembled by angle-irons. The bottom plate is slotted for the Elswick compressor.[5] This compressor is a modification of the American 15-inch one. It is made up of six bars of plate-iron, all of which are movable and which are placed lengthwise in the slide like the wooden balks in the American type. Seven plates hang through the slot in the bottom plate of the carriage, being loosely secured to it. The plates and bars are pressed together by rocking levers worked by screw-shafts, the shafts being worked by levers. The screws on the shafts are of different pitch. That on the right is called the compressing, having a quick pitch; when it is moved it presses the plates against the other lever, which, having a finer-pitched screw, is called the adjusting. The lower end of the adjusting lever is prolonged to form a trip-stop so that the recoil of the gun will throw the lever down automatically.

7-inch Slide.

The front rollers of the carriage are permanently in action, whilst the rear ones are on eccentrics. The elevating-gear is the wheel and ratchet. The slide has a slope to the front of 3°. The slide-rollers are on eccentric axles. Attached to the rear of the slide is a simple system of winch-gear for running in and training. This is nothing more than a spur-wheel and windlass revolved by a pinion and crank. In using it, the fall of the in-tackle or training-tackle is caught over the windlass which is turned by the crank. In revolving slides, or slides which shift from one port to another, there is a separate attachment under the forward end, which is nothing more than a centre roller which when thrown into action raises the forward rollers clear of the deck; the after-end of the slide being held by a pivot-bolt, the forward one is swung to a new pivot-centre. This centre roller is thrown into action by gearing. Two ordinary bollard-heads are attached to the rear of the slide, so that the carriage may be held back or veered out in a seaway by turns of the in-tackle falls about them.

Carriage and Slide for 8-inch M. L. R.

8-inch Slide.

The carriage is similar to the 7-inch, except that instead of being fitted for tackles it is provided with Scott’s nipping-gear and endless chain.[6] The chain is a slide attachment. The nipping-gear consists of a heavy iron stirrup, movable in a vertical direction by means of an eccentric and lever. The chain passes freely through this stirrup when it is down, but on throwing it up the links of the chain are caught in the teeth of a sprocket-plate fastened to the bed-plate of the carriage, so that the movement of the chain carries the carriage with it. The slide is similar to the 7-inch, except that the Scott chain and gearing is used, which also traverses the slide. There are two chains, one at each side of the slide, which are revolved by pinions at either end. At the rear end the pinions are on a heavy axle, which is revolved by a crank and gearing. For training, this gearing is connected to a short shaft, having a pinion at its forward end, which gears in a metal rack on the deck; this shaft may be revolved or fixed at will by means of a pawl-wheel and screw-break, so that in training the slide can be traversed or fixed as desired. When the slide is a shifting one, the same gearing is used to swing the forward end of it around, by means of another pinion which is shipped just in front of the forward end of the slide. The compressor is the Elswick pattern.

Elswick Compressor.

Carriage and Slide for 9-inch M. L. R.

The broadside 9-inch carriage is the same as the 8-inch; that for ships of the Sultan class differs in several particulars. The carriage is very low, its bottom plate coming well down inside of the slide. It is a double-plate carriage built on a cast-iron frame, the outer plate coming to the top of the slide, whilst the inner one is carried down inside. The rollers are completely hidden in their recesses, the forward ones being permanently in action, whilst the rear ones are on eccentrics. The rear axle between the rollers is bent down so as to give room for the breech of the gun in elevating.

9-inch Elevating-Gear.

The compressor fitted to this carriage is called the bow-compressor. It consists, on each side, of a bow or cramp pivoted at the centre, so that one arm projects inside the carriage through the bracket. A hinged plate is secured to the inner end, while the outer one holds an adjusting-screw which is worked by a hand-wheel, the latter having a pawl to hold it in any desired position. A brass arc near the face of this wheel graduated up to 17° shows the amount of compression. Two projecting pieces are attached to the side of the carriage to support the compressor-plates which hang upon them. These plates are three in number, the two inner ones being tapered, whilst the outer one is square-faced and much heavier. When the carriage is mounted on the slide, these tapering plates lie between the outer side of the slide (the T of which is filled out with wood) and two compressor-bars, which are tapered to correspond with the plates. The adjusting-screw takes against the outer plate, and by turning it the plates and bars are jammed together. The advantage of this compressor is that when once set it is self-acting, going out of action when the carriage is raised on its rear rollers, and coming into action by the weight of gun and carriage when the rollers are down.

Bow-Compressor.

Scott Nipping-Gear.

The Scott nipping-gear is used, but it is single, the chain traversing the middle of the slide. The slide has no peculiarities except its height, which is greater than that of the 8-inch.

Carriage and Slide for 10-inch M. L. R.

The carriages for ships of the Sultan class are the same as those for the 9-inch, except that the rear rollers are thrown in action by means of a hydraulic jack attached to the left bracket, there being a capstan-head arrangement at the other end of the axle for use in case the jack should break down. ([For turret-carriage, see turret-carriage of 11-inch].) The slide is similar to that of the 9-inch, except that instead of the bow-compressor two hydraulic recoil cylinders are used, one at each side of the slide.

Hydraulic Recoil Compressor.

Carriage and Slide for 11-inch M. L. R.

11-inch Small-Port Carriage.

The carriages for ships of the Temeraire or Hotspur class are the same as the 9-inch ones. The turret-carriage is of the muzzle-pivoting type. This carriage presents the peculiarity of having one bracket larger than the other, in order to allow for the circular shape of the turret. The general frame of the carriage is similar in shape to the ordinary type, being double plate on a cast-iron frame, with an interior wrought-iron frame which serves as a guide for the saddle. The gun is supported by the trunnions in a saddle which is nothing more than a massive fork, the leg of which is a hydraulic piston-rod. The arms, containing the trunnion-holes, are supported in the framework of the brackets. The hydraulic cylinder projects through and is secured to the bottom plate of the carriage, and the double-acting pump-brake is attached to a spindle passing through the bracket.

The gun does not rest permanently on the hydraulic, but when at the middle or top of its elevation the saddle-arms are supported by iron blocks, which are put in place through slits in the brackets. When the gun is down the saddle rests on the bottom of its slots. At the low level the gun gets 13° elevation, and at the high level 6° depression. The rear rollers are thrown in action by means of a double-acting hydraulic. The elevating-gear for this gun is different from that of the smaller calibres. Instead of having a curved ratchet attached to the gun, the ratchet in this case is pivoted to the carriage, and a gearing and traveller being clamped to the cascabel of the gun, the breech elevates or depresses up and down the stationary ratchet. This carriage is provided with Scott’s nipping-gear and the bow-compressor, the latter being heavier and double, working on both sides of the slide-plates. These carriages are provided with breechings which pass around a fitting bolted to the inside of the front transom. Additional hydraulic jacks are placed underneath the arms of the saddle for use in case the central one gives out. The slide is similar to the 10-inch, where traversing slides are used. In turrets the slide is a fixture. (See 12-inch slide.)

Carriage and Slide for 12-inch
and 12½-inch M. L. R.

The carriage for turrets of the Devastation class is similar in general to that of the 11-inch. The hydraulic lift for the saddle is not a part of the carriage, however, but a part of the ship, there being two rams, one for raising the gun when run out, and one for raising it when run in. The elevating-gear is also different, in having an arrangement for altering the height of the stationary ratchet to correspond with the different levels of the trunnions. The slide is provided with hydraulic recoil cylinders, which also act as the running in and out power. The piston-head has no holes bored in it, but when the gun recoils the oil is driven out of the cylinder, the flow being regulated by a balanced valve. The pump to move the hydraulic is worked by steam, the direction of the movement being controlled by a lever in the turret.

Carriage and Slide for 16-inch M. L. R.

There is no carriage proper for the 16-inch gun, the trunnions resting in saddles on beams fixed in the turret. Hydraulic piston-rods are attached to each saddle, the two cylinders being connected by a pipe to equalize the strain. The breech of the gun rests on a third block which travels in guides. These guides are hinged at the rear, the forward ends resting by means of a cross-head on the piston of a vertical hydraulic cylinder. By means of this the gun is elevated or depressed. The gun is run in or out, elevated, and loaded by hydraulic power.

Loading Arrangements.

81-ton Gun-Slide and Trunnion Saddles—
Hydraulic Loading Arrangements.

With the lighter calibres and broadside guns the usual loading methods are used, the heavy charges and projectiles being transported by means of railways either on deck or under the beams (the projectile in the latter case being slung to a traveller), and raised to the muzzle of the gun by a small davit shipped at the proper point on the slide. With the heavy turret-guns, automatic loading is resorted to. To accomplish this, a hole the size of the bore of the gun is worked in the turret underneath the port. Athwartship openings are left in the turret casing of the main-deck, in front of which are placed a hydraulic lift and the hydraulic extension rammer. The gun being run in, the turret is revoved until the port comes over the station of the rammer. The muzzle is then depressed, and the gun started out until it rests at the loading-hole. The rammer, which is also the sponge, being fixed permanently at the proper angle, is started ahead by a lever and is pushed to the bottom of the bore. On bringing up, a small spring at one side of the rammer-head is pressed, which opens a valve and turns on a stream of water. The rammer being withdrawn, the charge is run up in a hand-car on to the hydraulic lift, by which it is raised to the muzzle. A wad is shipped on the head of the rammer, and the latter, being started ahead, pushes the charge home. Owing to the shape of the rammer-head, the valve-spring cannot be pressed in pushing the charge down, so there is no danger of turning on the water. The position of the rammer-head in the bore is denoted by a simple pointer worked by a string, the other end being attached to the rammer-head. This crude arrangement is frequently out of order, and but little attention was paid to it until its importance was brought forcibly into notice by the double loading and consequent explosion of one of the Thunderer’s guns. One drawback to this system of loading is the care necessary to put the projectile on its car in one exact position, in order that the studs may come opposite their grooves. The car itself must be built at a certain fixed angle to bring the charge exactly in line for loading.

Hydraulic Recoil Press.

GUNPOWDER.

Gunpowder is graduated, according to size of grain and type, into seven distinct classes.

Service Pistol Powder is used for Colts’ and Adams’ pistols and for the bursting charges of shrapnel. It passes through a 44 and rests on a 72 mesh sieve.

Service R. F. G. Powder is used for rifled small-arms, except the Martini-Henry, Gatling guns, and pistols. It passes through a 12 and rests on a 20 mesh sieve. Density, 1.6.

Service R. F. G.² Powder is used for Martini-Henry rifles and Gatling guns. It is of the same size as the R. F. G., but greater density—1.72.

L. G. Powder is used in smooth-bores, and in rifled guns below 7 inches. This powder is being withdrawn as of inferior quality.

R. L. G. Powder is used for full charges in guns of 7 inches and upward where the weight of charge does not exceed forty pounds. It passes through the 4 and rests on the 8 mesh sieve.

P. Powder is used for battering-charges of all rifled guns of 7 inches and above, up to 12½ inches, and for all service charges of forty pounds and upward. The grain is cubical, ⅝ of an inch on a side.

P.² Powder is used with the 12½-inch and upward. This powder is cubical, 1½ inches on a side.

Gunpowder is graduated according to its fitness for use into six classes:

Class I. Service.—All new powder. All returned powder found to be uninjured.

Class II. Blank.—Powder from broken-up cannon-charges too dusty for Class I. Powder from broken-up small-arm ammunition. Service powder found too dusty for use in cartridges.

Class III. Shell.—Powder found too dusty for Class II.

Class IV. Doubtful.—All powder returned into store and waiting examination.

Class V. Condemned for Sale.—Powder too much deteriorated for the higher classes.

Class VI. Condemned for Extraction.—Powder obtained from shells, and powder found to have been too much damaged for any use except for the extraction of the saltpetre.

CARTRIDGES.

Cartridge-bags are made either of serge or of silk cloth.

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.

Woolwich Shrapnel.

Woolwich Common Shell.

Woolwich Case-Shot.

Woolwich Double Shell.

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.

Zinc Passing-Box.

Armstrong Segment Shell.

Armstrong Shrapnel.

Woolwich Cartridge.

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.

Palliser Shot.

Papier-maché Wad.

Brass Gas-Check for
Projectiles.

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.

Boxer Time-Fuse.

Armstrong Time-Fuse.

Armstrong Percussion Fuse.

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.

Pettman Percussion Fuse.

Laboratory Percussion Fuse.

PRIMERS.

Electrical Primer.

Quill Friction Primer.

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.

Centre Hind-Sight—Muzzle-Loaders.

Wood Scale.

SIGHTS.

Sliding Leaf Tangent Sight—Muzzle-Loaders.

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.

Barrel-Head Tangent-Sight—Breech-Loaders.

(Screw.)

(Drop.)

Fore-Sight.

Sliding-Leaf Tangent-Sight—Breech-Loaders.

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.

Palliser Converted Gun.
(10-inch Rodman Smooth-Bore
converted to an 8-inch Rifle.)

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 Muzzle-Loader.

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.

Whitworth Breech-Loader.

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.

Whitworth Projectiles.

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.

Vavasseur Gun and Carriage.

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.