The Point blank range of Brass, 12, 6, and 3-pounders is 200 yards, from which to 600 yards, each degree increases the range 100 yards, and from 600 to 1000, each degree increases it 50 yards.

Note.-For Weights, Dimensions, Ranges, Charges, &c., vide Tables.

HOWITZERS.

Howitzers are a short description of Ordnance, either Brass, or Iron, and are used for projecting Shells. Their principal advantages are that they can be more easily loaded, and are considerably lighter, proportion to their calibre, than Guns; and they also may be used as Mortars. They have no dispart, the diameter of the base ring, and swell of the muzzle being equal, except in the 24, and 12-pounders; which, however, are provided with a patch to make up the difference.

Millar's howitzers differ from the old pattern in the increased length, being from six to ten calibres; and in the conical form given to their Chambers (called Gomer) which are the frustrum of a cone, terminating in an hemisphere.

Note.-Vide Tables for Weights, Dimensions, Ranges, Charges, &c.

CARRONADES.

A Carronade is a short piece of Iron Ordnance, with a loop under the reinforce instead of trunnions. Its construction is materially different to that of guns; having a chamber; a part scooped out inside the muzzle forming a cup; also a patch on the reinforce. They take their name from the Carron Foundry (where they were first cast for the Navy in 1779), are considerably lighter than Guns of similar calibres, and are fired with charges of about one-twelfth the weight of the shot.

Carronades are chiefly used on board ship, but occasionally in casemates, and retired flanks of fortresses.

The highest charge is one-eighth the weight of the shot.
The lowest charge one-sixteenth do.

do.

Note. For Weights, Dimensions, Ranges, &c., vide Tables.

MORTARS.

Mortars differ from Guns in the construction of their bore, and also in their form, which is considerably shorter, the metal being much thicker, and the trunnions being at the extremity of the breech.

They are used for throwing Shells into a town, or battery, setting fire to and overthrowing works, blowing up magazines, and breaking through the roofs of barracks, casemates, magazines, &c. They are distinguished from each other by the diameter of their bore. Their chambers are in the form of a frustrum of a cone, in which the powder

1

19

is more concentrated; the Shell fits close to the sides of the piece, and thereby receives the whole force of the expansion of the powder. The greatest charges their chambers will contain, and the corresponding Ranges, are as follows:

When Mortars are used in firing on Inclined planes, up or down hill, should the inclination be considerable, take half the angle it makes with the horizon, and add it to, or subtract it from 45 degrees (which is for a medium plane), and it will give the greatest range upon the required plane.

Note.-Vide Tables of Dimensions, Weight, Charges, Ranges, &c.

VALUE OF ORDNANCE.

BRASS ORDNANCE.

Dependent on the market price of metals; at present the value of gun metal is £180 a ton,

IRON ORDNANCE.

The value is variable according to the market price of iron; at present the value is £20 a ton.

PROOF OF ORDNANCE.

All natures of Ordnance undergo several kinds of proof before they are received into the service :

1st. They are ganged as to their several dimensions, internal and external; as to the justness and position of the bore, the chamber, vent, and trunnions, &c.

2nd. They are fired with a regulated charge of powder and shot, being afterwards searched to discover irregularities, or holes produced by the firing.

3rd. By means of engines, an endeavour is made to force water through them.

4th. They are examined internally by means of light, reflected from a mirror.

IRON GUNS.

The guns are first examined as to their proper dimensions, in which no more than 3 of an inch variation is allowed; and in the diameters of the bore only 033; but in the position of the bore⚫ 25 of an inch out of the axis of a piece is allowed.

They are then fired twice with the charge in the following table, with one shot and two high junk wads, and examined with a searcher after each round.

In this examination they must not have any hole or cavity in the bore of two-tenths of an inch in depth behind the first reinforce ring, or one-fourth of an inch in depth before this ring.

Nature

42 Pr. 32 Pr. 24 Pr. 18 Pr. 12 Pr. 9 Pr. 6 Pr. 3 Pr.

From 3 to 12 pounders the diameter of the bore must not vary more than ⚫025 of an inch, nor in any dimensions'more than 2.

The 12 and 9 pounders are fired twice, the remainder three times. Any hole 15 of an inch upwards, or sideways in the bore, or 1 in the bottom, between the breech and first reinforce; or 2 of an inch upwards, or sideways, or 15 in the bottom of the bore before the first reinforce ring, will be sufficient to condemn them.

MORTARS, AND HOWITZERS.

The exterior dimensions are in no respect to deviate more than 1 of an inch in the 10, and 8 inch Howitzers, and 05 of an inch in the 24, and 12 pounder Howitzers, and Royal and Coehorn Mortars, and Howitzers. Their bores and chambers must not deviate from their true diameters, or positions more than ⚫025 of an inch.

PROOF CHARGES.

The Brass Mortars, and Howitzers are fired twice with their chambers full of powder, and an iron shell. The Mortars on their own beds at an elevation of about 75 degrees, and the Howitzers on their carriages at an elevation of about 12 degrees. The Iron Mortars are proved with a charge equal to the full chamber, and a solid shot equal in diameter to the shell. Royal or Coehorn Mortars, and also 24, and 12 pounders, or Royal Howitzers, having a hole of 1 of an inch in depth in the chamber, or 15 of an inch in the chase are rejected. A hole 15 of an inch in depth in the chamber, or ⚫2 of an inch in the chase is sufficient to condemn the 10, and 8 inch Howitzers. For the 13-inch Sea-service Mortar a cylinder weighing 4 cwt. is used for proof,

CARRONADES.

The bores, and chambers of Carronades must not deviate more than 05 of an inch from their true dimensions, and positions.

PROOF CHARGES.

They are proved with two rounds, with their chambers full of powder, and one shot and wad. A hole of 2 of an inch in depth in the bore, or 1 in the chamber condemns the piece.

WATER PROOF.

All Ordnance, after having undergone the before-mentioned proofs, and the subsequent searchings, are subject to the Water proof. This is done by means of a forcing pump, having a pipe or hose fitted and secured to the mouth of the piece, and a plug to stop up the vent.

After two or three efforts to force the water through any honeycombs, or flaws, which there may be in the bore, they are left to dry, and generally the next day examined by light reflected from a mirror. If the bore should contain any small holes, or flaws which have not been discovered by the former proofs, they are very readily found by this, as the water will continue to weep or run from the holes, after the solid parts of the bore are perfectly dry.

When a gun bursts in proving, the remainder in proof at the same time are subjected to another proof round.

Ordnance condemned, for any of the foregoing reasons as unserviceable, is marked as follows::-

Great attention should be paid to the care and preservation of iron Ordnance when in Depôt, or on Service, to prevent the irreparable injury Guns sustain from rust and corrosion.

With this view the first step to be taken is to clear their bores and exterior surfaces from all rust and dirt, which is done on the inside with circular Spring Scrapers, fixed on the end of a long shaft or handle: these scrapers are made to press strongly on the sides of the cylinder, and by being drawn backwards and forwards by two or three efficient labourers, will remove the rust, and, if not in a very bad state, will restore a regular smooth surface; the bottom or end of the bore is also scraped with a tool for that purpose, and the vent is

opened by passing a square steel rimer of its diameter through it,
gently turning the tool round until the vent is clear; after which the
bore must be well brushed out, first with a hard round brush, and
then with a Turk's-head brush, so that not the least dirt remains in
it. This being performed, the first coat of lacquer may be laid on, to
which, when dry, a second is to be added. This is done with a
common painter's brush, fixed vertically on the end of a staff suffi-
ciently long to reach down the cylinder; and the bottom of the bore
is lacquered by another brush fixed horizontally at the end of the
staff; the outside or exterior parts of the pieces are also to be well
scraped with an old sea-service sword, or steel tool of that nature,
tolerably sharp, especially about the mouldings, where former coatings
and dirt have accumulated; and when the rust will not give way, it
should be slightly hammered, so as to loosen it. These operations
must be continued until the whole coat of old paint, rust, or dirt, is
completely removed, after which the dust must be well brushed or
rubbed off, and the piece will then be fit to receive its first coat of
anticorrosion, to which, when dry, a second is to be added.

Before the work is commenced the pieces should be arranged as nearly as possible in the places where they are to remain, as too much rolling is apt to disturb the coating of paint, especially before it has gained sufficient hardness to be durable.

The following objects also require to be particularly attended to-

viz.:

In skidding Guns, &c., care must be taken that they are laid under metal, so that their muzzles may be sufficiently inclined downwards to prevent rain or any moisture lodging, and the bores from time to time should be swept out, as dust or sand blowing into them and being suffered to remain, would be very destructive; nor should the Guns be ever stacked one over the other, if the space where they are kept is sufficiently large to admit of their being laid in single tiers.

After the Ordnance is once got into a complete state of preservation, by following these instructions, very little trouble or expense will attend their being kept so, for a slight coat of anticorrosion on the exterior, and a thin coat of lacquer in the cylinder every three or four years, is all they will require, provided they are every now and then brushed out as before stated.

On coating the Guns, it may be found useful to let the painter mark on them the date, which will show how long it lasts, as this may differ at different stations, especially such as are exposed to much damp air, and it will afford the means of calculating the necessary demands of articles for this purpose at stated periods.

The same rules are to be observed in the preservation of all iron Ordnance mounted on works, with regard to the application of lacquer, and anticorrosion, and the precautions of keeping the pieces laid under metal, and frequently brushing out their bores, &c., as recommended in the foregoing instructions,