When the circumference of the Cartridge is not uniform, each Cartridge is made of two pieces, and the dimensions given are for one piece only.
FUZES, OLD PATTERN.
The wooden cases for holding the Fuze composition are made of well-seasoned beech. The interior diameter of the cup is equal to three times that of the bore, and its depth is equal to 1½ of the said diameter. The thickness of wood at the bottom of the bore is equal to two diameters.
Fuzes, being bored for Field guns, or cut to the length required for the range of Garrison guns, are made to fit the Shell correctly by means of a rasp and cutter; after which they are carefully driven into the Shell with a mallet and setter, leaving only the cup of the Fuze out of it. The Fuze is uncapped when placed in the piece.
All natures of Fuzes, when driven with the above composition, burn one inch in five seconds; but when driven with mealed powder, they burn two inches in the same time.
BOXER’S FUZE.
The composition bore is made excentric with regard to the exterior, and two powder channels are bored upon that side in which there is the greatest thickness of wood. A hole is bored through the mealed powder at the top, and into the fuze composition, to insure the ignition of the fuze composition from the priming. Two rows of holes, two inches apart, are made into the powder channels, and the bottom hole in each row is continued to the axis of the composition bore. The small side holes, with the exception of the bottom ones, are filled with pressed powder, and a small portion of clay. The powder channels contain rifle powder, and the bottom side holes have a piece of quick match placed in them. Beyond this quick match, the powder channels in the fuze for common shells are filled with putty; but in the Shrapnell fuze the corresponding portion contains quick match, which is continued from one channel to the other through a groove made in the bottom. A piece of quick match is tied into the cup, and it is recommended that this quick match is laid over the side before the shell is set home. The bursting powder is contained in a tin cylinder,[10]and is admitted through a hole at the bottom of the socket. There is a small hole in the side of the shell, through which the balls, and composition, which is run between them, are admitted.It is recommended that the bursting powder be placed in the tin cylinder before going into action, and the plug covered with serge, inserted in the fuze hole. The bursting powder can be speedily removed from the shell, if necessary; and, from its being separated from the balls, it will not be liable to injury, even when subjected to the action of travelling.
A simple boring-bit is supplied to each gun, in case the borer, specially made for the fuze, is lost, or damaged.
Captain Boxer’s 5½ inch fuzes are to be adopted for all natures of guns and howitzers, one inch in length for Shrapnell shells, and two inches in length for common shells.
FUZES, METAL.
Fuzes, for the Naval service specially, are formed of gun metal, and are screwed into a gun metal bouched screw hole in the shell.
Metal fuzes are of three natures, viz., 3-inch, 4-inch, and short-range Fuzes. The first is driven with mealed powder, and will burn seven seconds; the second is driven with fuze composition, and will burn twenty seconds; and the short-range fuze is also driven with the composition, and will burn two seconds. These fuzes are driven and primed precisely the same as wooden fuzes; but instead of being capped with canvas, have a screw metal cap.
The fuzes are screwed into the shells, the holes of which are bouched with metal to receive them; they are screwed into the left hand, so that unscrewing the cap in the same direction prevents the possibility of the fuze being loosened by that operation.
The diameter of the fuze holes for all natures of shells, fitted to receive metal fuzes, is exactly the same.
A 3-inch metal fuze will burn seven seconds, and is calculated for ranges not exceeding 1,900 yards. A 4-inch metal fuze will burn ten seconds, and is not to be used at a greater distance than 2,400 yards.
Bickford’s Water Fuze, which burns about two or three feet in a minute, may be advantageously used for exploding gunpowder under water, for the destruction of booms, vessels, &c.
GREASE.
The composition used for greasing wheels is composed of equal parts of tallow and coarse sweet oil melted together, and it is made up in kegs of 28 lb. each. In warm weather the proportion of tallow must be increased.
GRENADES, HAND.
A Land service Hand grenade weighs 1 lb. 13 oz., and may be thrown from 40 to 60 feet. The diameter of the Fuze composition is ·2 of an inch, length 2·25 inches, and weight 3 drams.
Fuze Composition.
Saltpetre, 3 lb. 4 oz.; Sulphur, 1 lb.; Mealed powder, 2 lb. 12 oz.
On service the Grenades are charged with 1½ oz. of powder.
GUN COTTON.
Although there appears no prospect of Gun cotton being used in the British service as a substitute for gunpowder, it is advisable that every Artillerist should be cognizant of its merits and demerits; for circumstances may arise when this new impulsive power may be advantageously employed. The exploding cotton is thus prepared:—Common well-cleaned cotton is dipped for about half a minute in highly-concentrated nitric acid (made by the distillation of ten parts of dried saltpetre, and six of oil of vitriol), and then instantly placed in water, which must be often renewed, in order to free the cotton from the acid with which it is impregnated. Care must then be taken that all the knotty particles of the cotton are properly disentangled, and that it is thoroughly dried. After the explosive preparation is ready for use, the smallest portion explodes when struck on an anvil with a hammer, like fulminating-powder; when kindled with a glowing body, it takes fire just like gunpowder; and, when used in a gun, its operation, though in a far greater proportion to its weight, is similar to that of gunpowder. Gun cotton is employed in the same manner as gunpowder: a piece of it is rammed down the barrel, then a bit of wadding, and after that a ball; a copper cap ignites and explodes the cotton.
To Dr. Otto, professor of chemistry in Brunswick, we are indebted for the foregoing description of the preparation of the explosive cotton; and the intrinsic value of this impulsive agent has been ascertained by Colonel Mordecai, at Washington, in 1845, 1847, 1848. The following are the results of this scientific officer’s experiments for the purpose of determining the fitness of Gun cotton, as a substitute for gunpowder in the military service:—
1. Explosive cotton burns at 380° Fahrenheit, therefore it will not set fire to gunpowder when burnt in a loose state over it.
2. The projectile force of explosive cotton, with moderate charges, in a musket or cannon, is equal to that of about twice its weight of the best gunpowder.
3. When compressed by hard ramming, as in filling a fuze, it burns slowly.
4. By the absorption of moisture, its force is rapidly diminished, but the force is restored by drying.
5. Its bursting effect is much greater than that of gunpowder, on which account it is well adapted for mining operations.
6. The principal residua of its combustion are water and nitrous acid; therefore the barrel of a gun would be soon corroded, if not cleaned after firing.
7. In consequence of the quickness and intensity of its action, when ignited, it cannot be used with safety in the present fire-arms.
8. An accident on service, such as the insertion of two charges before firing, would cause the bursting of the barrel; and it is probable that the like effect would take place with the regular service charges, if several times repeated.
GUNPOWDER.
The component parts of Powderare 75 parts of nitre, 10 of sulphur, and 15 of charcoal.
Cylinder powderis made from charcoal that has been burnt in iron cylinders; andPit powderfrom charcoal burnt in common pits.
Gunpowder, when ignited, expands with a velocity of about 5,000 feet per second; and the pressure of the fluid is about 2,000 times that of common air.
One pound of Powdermeasures 32 solid inches.
A cubic foot of Government powderweighs about 58 pounds.
Gunpowder is manufacturedby reducing the nitre, sulphur, and charcoal to powder; they are then mixed, moistened with water, and again mixed in a mill for five or six hours, or until the mixture is as intimate as possible, for upon this the strength of the powder chiefly depends.
When taken from the mill, the composition is put in a press, and formed into hard cakes about a quarter of an inch thick; these, when dry, or nearly so, are broken by wooden mallets into small pieces, and reduced into grains by being put into sieves, and forced by means of a wooden roller through circular holes of the proper diameter.
Good powdershould be devoid of smell, and of uniform colour, approaching to that of a slate. The particles should be perfectly granulated, and free from cohesion. It should admit of being readily poured from one vessel to another.
In powder that has become damp, large lumps are formed: should the damage, however, not be very considerable, these concretions may be reduced by drying the powder in a hot-air stove, rubbing and loosening the grains; but powder thus affected never thoroughly regains its lost strength.
To test the purity of powder.—Lay a dram of it on a piece of clean writing-paper, and fire the heap by means of a red-hot iron wire: if the flame ascend quickly with a good report, leaving the paper free from white specks, and without burning holes in it, the goodness of the ingredients and proper manufacture of the powder may be safely inferred.
Good powderblasted upon a clean plate of copper should leave no track or mark of foulness.
Powder exposedfor 17 or 18 days to the influence of the atmosphere ought not to increase materially in weight. One hundred pounds ofpowder should not absorb more than twelve ounces: if it increase in weight more than one per cent., the powder should be condemned.
Proof of Gunpowder.
To prove the strength oflarge grain or common powder, 2 ounces are fired from 8-inch Gomer mortars (at an angle of 45°), placed on stone beds, and so fixed as not to recoil. These mortars are loaded with shot weighing 68 pounds, and the average of the ranges, with Government powder of Waltham Abbey, is 250 feet. Powder made of common pit charcoal will only project such a ball, under the same circumstances, about 220 feet; and powder that has been re-stoved will only produce a range of from 107 to 117 feet.
A musket, charged with two drams offine grained or musket powder, should drive a steel bullet through 15 or 16 half-inch elm boards, placed three quarters of an inch from each other, the first board being set at 40 inches from the muzzle of the musket: with re-stoved powder, the bullet will only perforate from 9 to 12 of the boards.
The quality of large grain powder is ascertained by its general appearance, its firmness, glazing, uniformity of grain, and density.
POWDER MARKS.
The various sorts of Powder are distinguished by the following marks on the heads of the barrels:—
RedL G, or F G, denotes powder of the best quality.WhiteL G, or F G, is an inferior Powder for salutes, &c.
POWDER MAGAZINES.
To ascertain if a Magazine is damp.—Soak a piece of sponge in a solution of salt of tartar, or common salt and water: let it be well dried and weighed, and then be placed in the magazine, which, if damp, will cause the sponge to become heavier.
A small weight, suspended by a piece of catgut, or hair, will also discover moisture, causing the former to contract and the latter to lengthen.
POWDER BARRELS.
Whole Barrels contain 100 lb., and Half Barrels 50 lb., of powder, whether fine or coarse.
Dimensions of Powder barrels.
BUDGE BARRELS.
Weight of Barrel, copper-hooped, 10 lb., hazel-hooped, 6 lb.
BOXES TO CONTAIN POWDER, CORRESPONDING TO THE BARRELS.
These boxes are lined with copper, tinned.
HANDBARROWS.
Length, 5 ft. 3 in.Breadth, 2 ft.Weight, 19 lb.
HANDSPIKES.
Length, 5 ft. Diameter at top, 1·25; Diameter at bottom, 2·75 inches. Length of square, 1 foot 9 inches. Weight of ten, 64 lb.
There is a larger kind, 6 feet in length; weight of ten, 100 lb.
LEVERS.
LIGHTS, BLUE.
Blue lights are used for signals, &c., and will burn half a minute.
LIGHTS, LONG (BOXER’S).
The paper case is 10 inches long, 6 inches of which are filled with composition; one end is left open to fix on a wooden holder; the other end is fitted with a nipple, on which a percussion cap is to be placed. By giving the cap a smart blow on some hard substance, it ignites the composition, which will burn for six minutes.
LIGHTS, LONG (OR STEVENS’).
The composition is similar to that for blue lights. The cases are made of brown paper, and are of the same diameter as the one-pound signal rocket. The case is cut to the length of 9·75 inches, one end being perforated at an inch from the bottom to allow a wooden pin to pass through it, for the purpose of attaching the handle to the case.
Two coats of paint are given to the cases.
A long light will burn five minutes.
LIGHTS, SIGNAL (BOXER’S)
This is similar to theLight, long, but has only one inch of composition.
MATCH, QUICK.
Four pounds of the gunpowder are mixed into a thin paste with a portion of the gum-waterboiling, in this the cotton is then immersed. Six pounds of gunpowder made into a stiff paste, with the remainder of the gum-water, is spread on the top of the match, which is afterwards reeled off, the remaining two pounds of powder being sifted on the match while on the reel, and some of the stiff paste being held in the hand through which the match passes.
MATCH, SLOW.
Slow matchis prepared from slightly-twisted hemp rope, which is dipped in a solution of lime water and saltpetre.
One yard burns about three hours. One skein, 35 yards, weighs seven pounds.
During the Siege of Gibraltar, Slow match was thus made:—Eight ounces of saltpetre were put in a gallon of water, and just made to boil over a slow fire, strong blue paper was then wetted with the liquor, and hung to dry. When dry, each sheet was divided into two parts, which were rolled up tight, and the outward edges pasted down. Each half sheet would burn three hours.
French slow matchis made by soaking light twisted white rope in a solution of one pint of rain water, and three quarters of an ounce of sugar of lead.
PARACHUTE, LIGHT BALL (BOXER’S).
This light ball consists of a paper shell, enclosing two tin hemispheres, one containing the composition, the other the parachute. The shell is fired from a mortar, having a fuze, fixed in the usual manner, which communicates with the bursting powder, opens the shell, and lights the composition in the hemisphere attached to the parachute, which, suspended in the air, renders conspicuous the objects required to be illuminated.
PENDULUMS.
A Pendulum is readily made with a musket ball, and a piece of silk. The length of a Pendulum is measured from the centre of the ball to the end of the loop on which it swings.
To find the length of a pendulum to make a given number of vibrations.
Rule.—As the square of the given number of vibrations is to the square of 60, so is the length of the standard (39·14 length for one second) to the length sought.
Or, multiply 39·14 by the square of the time required for the Pendulum to vibrate—viz., by the square of ½ = ¼, for ½ second; and by the square of 2 = 4 for two seconds.
To find the number of vibrations, the length of pendulum being given.
Rule.—Multiply 60 seconds by the square root of 39·14, divided by the length of the given pendulum.
Or say, As the given length is to the standard length, so is the square of 60 (its vibrations per minute) to the square of the number required.
PORTFIRES.
Portfires are of four different natures—viz., Common portfires, Percussion portfires, Miners’ portfires, and Slow portfires.
A common portfire is 16 inches long, and will burn 15 minutes.
PORTFIRES, PERCUSSION.
The percussion priming is added to these portfires at the stations where they are used (principally for the Coast Guard), and is simply a small glass globule, containing sulphuric acid. This is embedded in loose composition, which ignites on the globule being broken. A percussion portfire will burn 5 minutes.
PORTFIRES, MINERS.
PORTFIRES, SLOW.
The paper, which is called blue sugar-loaf paper, is wetted by dissolving 12 ounces of saltpetre in one gallon of water, wetting each sheet separately on both sides with a brush, one side being dried before the other is made wet.
Slow portfires burn from three to four hours.
Portfires were made during the Siege of Gibraltar in the following manner: Two ounces of nitre were dissolved in a gallon of water, and sheets of soft brown paper dipped in the solution; these, when dry, were rolled up to about the size of common portfires.
Portfires may be madeby boiling square rods of lime, birch, or poplar, in a solution of nitrate of lead for six hours (a quart of waterto every pound of the nitrate); the matches are then dried, and afterwards boiled in spirits of turpentine; they are then wiped and dried. A yard of this match will burn three hours.
COAST GUARD PORTFIRES.
Composition.
Saltpetre 8 lb. Sulphur 4 lb. Cylinder mealed powder 1 lb.
QUOINS.
ROCKETS.
There are two descriptions of Rockets:—
1st.—Signal Rockets.2nd.—Congreve Rockets.(VidePart VI.)
SIGNAL ROCKETS.
Signal rockets are of two natures—viz., 1 lb. and ½ lb. Rockets. They are fired from a tube, the ignition being effected by means of a percussion tube.
The head of a 1 lb. rocket contains 36 stars, and that of the ½ lb. rocket 24 stars.
SHELLS.
Shells are hollow iron Shot, and are of various descriptions, viz.:—
1st.—TheCommon shell, with one fuze hole, used in the attack and defence of fortresses, &c., against shipping, and troops.
2nd.—TheCarcass, which has three fuze holes, is filled with burning composition, and is used to set fire to towns, &c.
3rd.—TheCompound-shot, which is filled with lead to increase the impetus of the shot, and the extent of the range.
4th.—TheShrapnell shell, which is very destructive when used against bodies of Cavalry or Infantry, as it produces the same effect as common Case or Canister shot from guns or howitzers, but at a much greater range.[11]
All shells are now issued in the Field Service,loaded, and secured with a metal plug.
SHOT, CASE OR CANISTER.
The common Case or Canister shot consists of a number of balls packed in tin canisters of a cylindrical form: the balls being of different weights according to the size of the gun. For field servicethe balls are counted into the case, and laid in tiers, but for other purposes they are loosely thrown in till the case is filled. The top being soldered on, the bottom of the tin case is nailed on to the wooden bottom, and the heads of the nails are soldered. These shot should seldom be used at a greater distance than 300 yards, and even at that range they scatter so much as to be nearly unserviceable; but at from 100 to 200 yards they are very destructive.