Part 4

These amount to about 700 for guns. 400 for mortars. 1000 for stone do.

This proportion and arrangement is however made upon a supposition, that the place has no countermines to retard the progress of the besiegers, to a period beyond what is abovementioned; but the same author estimates, that a similar place, with the covert way properly countermined beforehand, and those countermines properly disputed, may retard a siege at least 2 months; and that if the other works be likewise effectually countermined and defended, the siege may be still prolonged another month.

The above proportion is therefore to be further regulated, as the strength of the place is increased by these or any other means. These considerations should likewise be attended to, in the formation of an estimate of ammunition and stores for the siege of a fortified place. See _Carriage, Platform, Park_, and the different natures of artillery, as _Gun, Mortar, Howitzer_, &c.

The small arms ammunition is estimated by this author as follows:

¼ of a pound of gunpowder, or 10 rounds per day, per man, for all the ordinary guards.

1¼ lbs. or 50 rounds per man, per 12 hours, for all extraordinary guards.

⅝ of a pound, or 25 rounds for every man on picket, during the period of his duty.

_AXLETREES_—See the word _Carriages_.

_BALLS_—of lead, of different natures.

+--------------+--------+----------+--------------+ | | Number | Diameter | Number made | | Nature. | to one | in | from one ton | | | Pound. | Inches. | of Lead. | +--------------+--------+----------+--------------+ |Wall pieces | 6¾ | .89 | 14,760 | |Musquets | 14½ | .68 | 32,480 | |Carbine | 20 | .60 | 44,800 | |Pistol | 34 | .51 | 78,048 | |7 Barrel guns | 46½ | .46 | 104,160 | +--------------+--------+----------+--------------+

Lead balls are packed in boxes containing each 1 cwt. About 4 pounds of lead in the cwt. are generally lost in casting. See _Shot_.

_BARRELS for powder_--Their dimensions.

+--------------------+----------+----------+----------+ | | Whole | Half | Quarter | | | Barrels. | Barrels. | Barrels. | | +----------+----------+----------+ | | Ft. In. | Ft. In. | Ft. In. | +--------------------+----------+----------+----------+ |Depth | 1 9.61 | 1 5.13 | 1 2.25 | |Diameter at top | 1 3.61 | 1 0.37 | 9.35 | | ” at bulge | 1 5.36 | 1 2. | 10.71 | | ” at bottom | 1 3.51 | 1 0.31 | 9.41 | +--------------------+----------+----------+----------+

The whole barrels are made to contain 100 pounds, and the half barrels 50 pounds of powder; but of late only 90 pounds have been put into the barrels, and 45 into the half barrels; which, by leaving the powder room to be shifted, preserves it the better.

_Budge Barrels_ contain 38 lbs.

Weight of barrel—copper hooped—10 lbs. ” ” hazle hooped—6 Length of barrel 10½ inches. Diameter 1 foot 1 inch.

_BASKETS._—Ballast, ½ bushel—weight, 5 lbs. Diameter, 1 foot 6 inches—length, 1 foot.

_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.

_Epaulment._—Breadth at bottom 23 feet. ” at top 18 Height within 7 ” without 6 ft. 4 in. Slope, interior ²/₇ of height. ” exterior ½ of height.

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 epaulment 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 epaulment. In confined situations the breadth of the epaulment may be only 12 feet.

_Embrazures._—Distance between } 18 feet. their centers } Openings, interior 20 inches. ” exterior 9 feet.

Height of the sole above the platform 32 inches.

NOTE. Where the epaulment is made of a reduced breadth, the openings of the embrazures are made with the usual breadth within, but the exterior openings proportionally less. The embrazures are sometimes only 12 feet asunder, or even less when the ground is very confined. The superior slope of the epaulment need be very little, where it is not to be defended by small arms. The slope of the sole of the embrazures must depend upon the height of the object to be fired at. The _Berm_ is usually made 3 feet wide, 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 epaulment.

NOTE. Though it has been generally customary to fix mortars at 45°, and to place them at the distance of 12 feet from the epaulment, 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 epaulment, but where they would be in equal security. If the mortars were placed at the undermentioned distances from the epaulment, 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 epaulment 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 epaulment; for when a battery is to be formed on the crest of the glacis, or on the edge of the counterscarpe 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 epaulment, 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 epaulment. When this is the case, the guns can seldom be placed nearer than 3½ 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:

90 fascines of 9 feet long.

20 fascines of 18 feet—for the embrazures.

This number will face the outside as well as the inside of the epaulment, which if the earth be stiff, will not always be necessary; at least not higher than the soles of the embrazures on the outside. This will require five of 9 feet for each merlon less than the above.

A mortar battery will not require any long fascines for the lining of the embrazures. The simplest method of ascertaining the number of fascines for a mortar battery, or for any other plain breast work, is to divide the length of work to be fascined in feet, by the length of each fascine in feet, for the number required for one layer, which being multiplied by the number of layers required, will of course give the number of fascines for facing the whole surface. If a battery be so exposed as to require a shoulder to cover it in flank, about 50 fascines of 9 feet each will be required for each shoulder.

Each fascine of 18 feet will require 7 pickets. ” ” ” 9 feet ” ” 4 ”

12 workmen of the line, and 8 of the artillery, are generally allotted to each gun.

If to the above proportion of materials, &c. for a battery of two guns, there be added for each additional gun, 30 fascines of 9 feet, and 10 of 18 feet, with 12 workmen, the quantity may easily be found for a battery of any number of pieces.

The workmen are generally thus disposed; one half the men of the line in the ditch at 3 feet asunder, who throw the earth upon the berm; one fourth upon the berm at 6 feet asunder, to throw the earth upon the epaulment, and the other quarter on the epaulment, to level the earth, and beat it down. The artillery men carry on the fascine work, and level the interior for the platforms. This number of workmen may complete a battery in 36 hours, allowing 216 cubic feet tn be dug and thrown up, by each man _in the ditch_ in 24 hours.

_Tools for the Construction of a Battery._

_Intrenching_—1½ times the number of workmen required; half to be pick axes, and half shovels or spades, according to the soil.

_Mallets_—3 per gun.

_Earth Rammers_—3 per gun.

_Crosscut Saws_—1 to every two guns.

_Handbills or Hatchets_—2 per gun.

This estimate of tools and workmen, does not include what may be required for making up the fascines, or preparing the other materials, but supposes them ready prepared. For these articles, see the words _Fascine_, _Gabion_, _Platform_, &c. and for the construction of field magazines for batteries, see the word _Magazine_.

NOTE. The following estimate of the quantity of earth which may be removed by a certain number of workmen in a given time, may serve to give some idea of the time required to raise any kind of works. 500 common wheel barrows will contain 2 cubic toises of earth, and may be wheeled by one man, in summer, to the distance of 20 yards up a ramp, and 30 on a horizontal plain, in one day. In doing which he will pass over, going and returning, about 4 leagues in the first case, and 6 in the last. Most men, however, will not wheel more than 1¾ toise per day. Four men will remove the same quantity to four times the distance.

In a soil easy to be dug, one man can fill the 500 barrows in a day; but if the ground be hard, the number of fillers must be augmented, so as to keep pace with the wheel barrow man.

_BEDS for Mortars._

+------------+-------------+--------------+-------+-------+-------+ |Nature. | Weight. | Tonnage. | Len. | Bre. | Ht. | +------------+-------------+--------------+-------+-------+-------+ | |cᵂᵗ. qʳˢ. lb.| tⁿˢ. cᵂᵗ. qʳ |ft. in.|ft. in.|ft. in.| | | | | | | | | Sea | 38 3 13 | 3 3 2 | | | | +--+---------+-------------+--------------+-------+-------+-------+ |13|Land Wood| 21 2 7 | 1 6 0 | 7 0 | 2 6 | 2 3 | | | ” Iron| 50 0 0 | 2 10 0 | 6 3 | 3 1 | 1 6 | +--+---------+-------------+--------------+-------+-------+-------+ | Sea | 32 2 14 | 2 2 2 | | | | +--+---------+-------------+--------------+-------+-------+-------+ |10|Land Wood| 10 0 20 | 0 4 2 | 6 6 | 1 8 | 1 10 | | | ” Iron| 23 0 0 | 1 3 0 | 4 8 | 2 4 | 1 1½ | +--+---------+-------------+--------------+-------+-------+-------+ |8 |Land Wood| 6 0 20 | 0 7 2 | 4 2 | 1 7 | 1 7½ | | | ” Iron| 12 0 0 | 0 12 0 | 4 0 | 1 11 | 0 11 | +--+---------+-------------+--------------+-------+-------+-------+ | 5½ Wood | 1 0 22 | 0 2 0 | 2 9 | 1 4 | 0 10 | | 4⅖ Wood | 0 3 11 | 0 1 2 | 2 4½| 1 2 | 0 9 | +------------+-------------+--------------+-------+-------+-------+ _Stool Beds for Guns._ +------------+-------------+--------------+-------+--------+------+ | | | | | Inch. | In. | |42 Pounders | 0 1 20 | 0 1 0 | 2 10 |11 to 8¾| 3¾ | |32 ” | 0 1 14 | 0 1 0 | 2 10 |10 5½| 3¼ | |24 ” | 0 1 14 | 0 1 0 | 2 9 |10¼ 6½| 4 | |18 ” | 0 1 12 | 0 1 0 | 2 8 | 9½ 6½| 3¾ | |12 ” | 0 1 10 | 0 0 2⅔ | 2 8 |10 6½| 4 | | 9 ” | 0 1 4 | 0 0 2 | 2 7 | 9½ 5¾| 3½ | | 6 ” | 0 1 0 | 0 0 1¾ | 2 6 | 9 4¾| 3½ | | 4 ” | 0 1 0 | 0 0 1 | 2 6 | 8¼ 5¼| 3 | +------------+-------+-----+--------------+-------+--------+------+

_BOXES for Ammunition._—The dimensions of the common ammunition boxes vary according to the ammunition they are made to contain, in order that it may pack tight: this variation, however, is confined to a few inches, and does not exceed the following numbers.

_Table of general Dimensions of Ammunition Boxes._

+-------+---------------------------------------+--------+ | | Exterior. | Weight | | +------------+------------+-------------+ when | | | Length. | Breadth. | Depth. | empty. | +-------+------------+------------+-------------+--------+ | | feet inch. | feet inch. | feet inch | lbs. | | From | 2 2 | 0 10 | 0 8½ | 20 | | To | 2 9 | 1 6 | 1 6 | 30 | +-------+------------+------------+-------------+--------+

Weight when filled, and Number contained in each.

+---------------------------+-----------------+---------------+ | | Weight of | No. of Rounds | | | Boxes when | contained in | | Nature of Ammunition. | filled with | each Box. | | | Ammunition. | | +---------------------------+-----------------+---------------+ | | cᵂᵗ. qʳˢ. lb. | No. | +---+--------+-------+------+-----------------+---------------+ | | |12 Prs.|Round | 1 1 10 | 8 | | | | |Case. | 0 3 15 | 6 | | | Shot +-------+------+-----------------+---------------+ | | fixed | 6 Prs.|Round | 1 2 7 | 12 | | | with | |Case | 1 0 15 | 12 | | | powder.+-------+------+-----------------+---------------+ | | | |Round | 0 2 25 | 16 | | | | 3 Prs.|Case | 0 2 23 | 14 | | +--------+-------+------+-----------------+---------------+ | B | |24 Prs.|Round | 1 1 26 | 6 | | o | | |Case | 2 0 0 | 6 | | x | +-------+------+-----------------+---------------+ | e | |12 Prs.|Round | 1 2 20 | 12 | | s | Shot | |Case | 1 2 22 | 8 | | | fixed +-------+------+-----------------+---------------+ | | to wood| |Round | 1 2 20 | 24 | | | bottoms| 6 Prs.|Case | 1 1 12 | 18 | | f | without+-------+------+-----------------+---------------+ | o | powder.| |Round | 1 1 0 | 30 | | r | | 3 Prs.|Case | 1 1 0 | 30 | | | +-------+------+-----------------+---------------+ | | |How’r. | 8 | 1 2 2 | 3 | | | | Case. | 5½ | 1 2 12 | 10 | | | | | 4⅖ | 1 2 22 | 20 | | +--------+-------+------+-----------------+---------------+ | | | | f | | | | | |How’r |8 i | 1 2 2 | 3 | | | Shells.|Shells.|5½ x | 1 2 12 | 10 | | | | |4⅖ e | 1 2 22 | 20 | | | | | d | | | +---+--------+-------+------+-----------------+---------------+

The common ammunition waggon will hold from 9 to 13 of these boxes in one tier.

The tonnage of ammunition in boxes is equal to its weight: about 12 boxes make one ton.

_BOMB Ketch._ The bomb ketches upon the old establishment carry one 13 inch and one 10 inch mortar; with eight 6 pounders, beside swivels, for their own immediate defence. The modern bomb vessels carry two 10 inch mortars, four 68 pounders, and six 18 pounders carronades; and the mortars may be fired at as low an angle as 20 degrees; though these mortars are not intended to be used at sea, but on very particular occasions; their principal intention, at these low angles, being to cover the landing of troops, and protect our coast and harbours. A bomb ketch is generally from sixty to seventy feet long from stem to stern, and draws eight or nine feet water. The tender is generally a brig, on board of which the party of artillery remain, till their services are required on board the bomb vessel.

_Instructions for their Management and Security in Action._

1. A Dutch pump, filled with water, must be placed in each round top, one upon the forecastle, one on the main deck, and one on the quarter deck; and furnished with leather buckets, for a fresh supply of water.

2. The booms must be wetted by the pumps before the tarpaulins and mortar hatches are taken off; and a wooden skreen, 5 feet square, is to be hung under the booms, over each mortar, to receive the fire from the vents.

3. The embrazures being fixed and properly secured, the port must be let down low enough to be covered by the sole of the embrazure. Previous to its being let down, a spar must be lashed across it, to which the tackles for raising it again must be fixed: this spar serves to project the tackles clear of the explosion.

4. The mortars must not be fired through the embrazures at a lower angle than 20 degrees, nor with a greater charge than 5 lbs. of powder.

5. Previous to firing, the doors of the bulkhead, under the quarter deck, must be shut, to prevent the cabin being injured by the explosion.

6. The bed must be wedged in the circular curb, as soon as the mortar is pointed, to prevent reaction; the first wedge being driven tight before the rear ones are fixed, in order to give the full bearing on the table, as well as the rear of the bed. The holes for dog bolts must be corked up, to prevent the sparks falling into them.

7. When any shells are to be used on board the bomb, they must be fixed on board the tender, and brought from thence, in boxes in her long boat; and kept along side the bomb ship till wanted, carefully covered up.

8. In the old constructed bomb vessels it is necessary to hoist out the booms; and raft them along side previous to firing; but in these new ones, with embrazures, only the boats need be hoisted out; after which the mortars may be prepared for action in 10 minutes.

_Proportion of Ordnance and Ammunition for a Bomb Ship, carrying two 10 Inch Mortars, to fire at low Angles, and at 45 Degrees, Four 68 Prs. and Six 8 Prs. Carronades._