Fascine Batteries, -

Gabion Batteries,

are batteries made of those machines, where sods are scarce, and the earth very loose or sandy. For a particular detail of all kinds of batteries, see Toussard’s Artillerist, No. I. c. 1.

Battery.—Dimensions of Batteries.

1. Gun Batteries.—Gun Batteries are usually 18 feet per gun. Their principal dimensions are as follow:

Ditch— Breadth 12 feet.

Depth 8

Note.—These dimensions give for a battery of two guns 3456 cubic feet of earth; and must be varied according to the quantity required for the epaulment.

Epaulement— Breadth at bottom 23 feet.

Breadth at top 18

Height within 7

Height without 6 ft. 4 in.

Slope, interior ?/? of h’gt.

Slope, exterior ?/? of h’gt.

Note.—The above breadths at top and bottom are for the worst soil; good earth will not require a base of more than 20 feet wide, which will reduce the breadth at top to 15 feet; an epaulement of these dimensions for two guns will require about 4200 cubic feet of earth, and deducting 300 cubic feet for each embrazure, leaves 3600 required for the epaulement. In confined situations the breadth of the epaulement may be only 12 feet.

Embrazures— Distance between their centers 18 feet

Openings, interior 20 inc.

Openings, exterior 9 feet

Height of the sole above the platform 32 inc.

Note.—Where the epaulement is made of a reduced breadth, the openings of the embrazures are made with the usual breadth within, but the exterior openings proportionably less. The embrazures are sometimes only 12 feet asunder, or even less when the ground is very confined. The superior slope of the epaulement need be very little, where it is not to be defended by small arms. The slope of the side of the embrasures must depend upon the height of the object to be fired at. The Berm is usually made 3 feet wide,[38] and where the soil is loose, this breadth is increased to 4 feet.

2. Howitzer Batteries.—The dimensions of howitzer batteries are the same as those for guns, except that the interior openings of the embrazures are 2 feet 6 inches, and the soles of the embrazures have a slope inwards of about 10 degrees.

3. Mortar Batteries.—Are also made of the same dimensions as gun batteries, but an exact adherence to those dimensions is not so necessary. They have no embrazures. The mortars are commonly placed 15 feet from each other, and about 12 feet from the epaulement.

Note.—Though it has been generally customary to fix mortars at 45°, and to place them at the distance of 12 feet from the epaulement, yet many advantages would often arise from firing them at lower angles, and which may be done by removing them to a greater distance from the epaulement, but where they would be in equal security. If the mortars were placed at the undermentioned distances from the epaulement, they might be fired at the angles corresponding:

At 13 feet distance for firing at 30 degrees.

21 20

30 15

40 10

over an epaulment of 8 feet high.

A French author asserts, that all ricochet batteries, whether for howitzers or guns, might be made after this principle, without the inconvenience of embrazures; and the superior slope of the epaulement being inwards instead of outwards, would greatly facilitate this mode of firing.

If the situation will admit of the battery being sunk, even as low as the soles of the embrazures, a great deal of labour may be saved. In batteries without embrazures, this method may almost always be adopted; and it becomes in some situations absolutely necessary in order to obtain earth for the epaulement; for when a battery is to be formed on the crest of the glacis, or on the edge of the counterscarp of the ditch, there can be no excavation but in the rear of the battery.

4. Batteries on a coast—generally consist of only an epaulement, without much attention being paid to the ditch; they are, however, sometimes made with embrazures, like a common gun battery; but the guns are more generally mounted on traversing platforms, and fire over the epaulement. When this is the case, the guns can seldom be placed nearer than 3?/? fathoms from each other. The generality of military writers prefer low situations for coast batteries; but M. Gribauvale lays down some rules for the heights of coast batteries, which place them in such security, as to enable them to produce their greatest effect. He says the height of a battery of this kind, above the level of the sea, must depend upon the distance of the principal objects it has to protect or annoy. The shot from a battery to ricochet with effect, should strike the water at an angle of about 4 or 5 degrees at the distance of 200 yards. Therefore the distance of the object must be the radius, and the height of the battery the tangent to this angle of 4 or 5°; which will be, at the above distance of 200 yards, about 14 yards. At this height, he says, a battery may ricochet vessels in perfect security; for their ricochet being only from a height of 4 or 5 yards, can have no effect against the battery. The ground in front of a battery should be cut in steps, the more effectually to destroy the ricochet of the enemy. In case a ship can approach the battery so as to fire musquetry from her tops, a few light pieces placed higher up on the bank, will soon dislodge the men from that position, by a few discharges of case shot. It is also easy to keep vessels at a distance by carcasses, or other fire balls, which they are always in dread of.

Durtubie estimates, that a battery of 4 or 5 guns, well posted, will be a match for a first rate man of war.

To estimate the materials for a battery.

Fascines of 9 feet long are the most convenient for forming a battery, because they are easily carried, and they answer to most parts of the battery without cutting. The embrazures are however better lined with fascines of 18 feet. The following will be nearly the number required for a fascine battery of two guns or howitzers: