PREFACE. (continued 4)

RICOCHET—Firing is not confined to any particular charge or elevation; each must vary according to the distance and difference of level of the object to be fired at; and particularly of the spot on which it is intended the shot shall make the first bound. The smaller the angle is under which a shot is made to ricochet, the longer it will preserve its force and have effect, as it will sink so much the less in the ground on which it bounds and its tenacity will of course present so much less resistance to the shot’s progress. In the ricochet of a fortification of any kind, the angle of elevation should seldom be more than 10°, to throw the shot over a parapet a little higher than the level of the battery. If the works should be of an extraordinary height, the piece must be removed to such situation, and have such charge, that it can attain its object at this elevation, or at least under that of 13° or 14°, otherwise the shot will not ricochet, and the carriages will suffer very much. The first gun in a ricochet battery should be so placed as to sweep the whole length of the rampart of the enemy’s work, at 3 or 4 feet from the parapet, and the rest should form as small an angle with the parapet as possible. For this purpose the guns should be pointed about 4 fathoms from the face of the work towards the interior. In the ricochet of ordnance in the field, the objects to be fired at being principally infantry and cavalry, the guns should seldom be elevated above 3 degrees; as with greater angles the ball would be apt to bound too high, and defeat the object intended. For ricochet practice see the different pieces of ordnance, as Gun, Mortar, and Howitzer.

Durtubie.

See also the words Platforms and Battery.

ROCKETS.—Composition.

Old Proportion. New Proportion.

lbs. oz. lbs. oz.

Saltpetre 4 0 — 4 4

Sulphur 1 0 — 0 12

Charcoal 1 8 — 2 0

Composition for the Stars.

Mealed powder 0 lb. 8 oz. Composition for rains

Saltpetre 8 0 to head sky rockets

Sulphur 2 0 is the same as the

Antimony 2 0 above for the rockets.

Isinglass dissolved 0 3½

Spirits of wine 1 pint.

Vinegar 1 quart.

General Table of Sky Rockets.

2 Pound. 1 Pound. ½ Pound. ¼ Pound.

Inch. Inch. Inch. Inch.

Case Exterior diameter 2.13 1.69 1.34 1.06

Interior diameter 1.529 1.214 0.961 0.761

Length before driving 15.97 12.67 10.05 8.25

Length of guage for the choke 1.5 1.25 1.0 0.75

Cylinders for heading. Diameter 2.84 2.25 1.79 1.39

Length 4.26 3.38 2.68 2.12

Cones for heading. Diameter 2.84 2.25 1.79 1.39

Height 4.26 3.38 2.68 2.18

Mallet for driving.—Weight 4 lb. 3 8 oz. 2 1 1 10

Nᵒ. of strokes 31 21 18 13

Copper Ladles for filling Sky Rockets.

Length, 1½ the exterior diameter of the case.

Diameter, equals the interior diameter of case.

Circumference, ¾ the interior caliber of the case.

Sky rockets are driven with composition up to 4½ exterior diameters of the case from the choke; and ⅕ of a diameter above the composition with good clay. They are bored and reamed up to 3½ diameters.

Dimensions of Sticks for Rockets.—General rules.

For rockets from ½ an ounce to one pound, the stick must be 60 diameters of the rocket in length: for rockets from one pound and upwards fifty or fifty two diameters. Their thickness at top about ½ a diameter, and their breadth very little more. Their square at bottom equal to ½ the thickness at top.

Nature of Rockets. 6 Pr. 4 Pr. 2 Pr. 1 Pr. ½ Pr. ¼ Pr. ⅛ Pr.

Ft. In. F. I. F. I. F. I. F. I. F. I. F. I.

Distance of poise from the point of the cone 4 1½ 3 9 2 9 2 1 1 10½ 1 8 1 3

Rockets of between 3 and 4 inches diameter have been observed to ascend as high as 1000 or 1200 yards; but the height of common rockets is between 450 and 600 yards; and their flight usually short of 7 seconds.

Jones, Robins, Lab.

ROPE—is always distinguished by its circumference: thus a two inch rope means a rope of 2 inches in circumference.

Rule for finding the Weight of Ropes.

Multiply the square of the circumference in inches, by the length in fathoms, and divide the product by 480 for the weight in cwt. See also Drag Ropes.

S and bags—are made about 27 inches long, and 15 diameter; 250 of these are required for each fathom of battery, or about 1680 for two guns or mortars.—See Tonnage.

SAP.—The sap generally commences about the second parallel, and sometimes sooner; and if the fire of the besieged is much slackened, may proceed both day and night. The sappers are usually divided into brigades of 8, and subdivided into divisions of 4 each; being the greatest number that can work at the sap at the same time. The leading sapper excavates 18 inches deep, and as much wide; the second, third, and fourth deepen the trench, each in succession 6 inches, and widen it as much; so that the four make a trench of 3 feet wide and 3 feet deep; after which the common workmen follow, and increase it in breadth and depth equal to the other trenches. The sap may proceed at the rate of 80 fathoms in 24 hours. As this work is very hard, the half brigades relieve each other every hour, and each sapper in his turn takes the lead. The whole brigade is relieved at the end of 6 hours. It is always customary in this dangerous work, to give the wages of those that are killed to the survivors. Sappers are generally armed with a helmet and breast plate. See Trenches, Parallels.

SECANT.—See table at the end of the word Gunnery.

SHELLS—For Mortars and Howitzers.—Their Dimensions, Weight, &c.

Nature. Weight. Diameter. Powder contained in Shells. Powder for Burning. Diameter of Fuze Hole. Thickness of Metal.

Outside Inside

Ct. qr. lbs. oz. Inches. lbs. oz. lbs. oz. Inches. Inches. Inches.

13 Inch 1 3 2 12¾ 10 4 6 12 1.837 1.696 2.05

10 ” 3 9 9¾ 4 5 2 10 1.57 1.45 1.575

8 ” 1 11½ 7¾ 2 12 1 14 1.219 1.127 1.2

5½ ” 15¼ 5¼ 1 12 0.894 0.826 0.822

4⅖ ” 8 4⅕ 7 5 0.832 0.769 0.653

Hand 3 11 3.49

Gren. 1 13 2.77 1½

French Shells, in French Weights and Measures.

Inches. lbs. Lines Po. Lines Po. Lines

12 Inch 150 12 17 5 15 9 15 16

10 ” 100 10 10 3 15 9 15 16

8 ” 43 8 4 1 1 12 11 10

6 ” 23 6 2 8 12 11 10 6 10

Dimensions of Shells for Guns and Carronades made with an equal Thickness of Metal.

Nature. 42 Pr. 32 24 18 12

Inches Inches Inches Inches Inches

Guns Diameter of the shell — Exterior 6.684 6.105 5.547 5.04 4.4

Interior 4.404 4.005 3.767 3.4 2.8

Thickness of metal 1.14 1.05 0.89 0.82 0.8

Diameter of fuze hole — Exterior 0.894 0.894 0.894 0.832 0.832

Interior 0.826 0.826 0.826 0.769 0.769

Powder for bursting oz. 14 11 12 9 5½

Carronades Diameter of the shell — Exterior 6.64 6.05 5.48 4.935 4.295

Interior 4.36 3.95 3.48 3.235 2.695

Thickness of metal 1.14 1.05 1. 0.85 0.8

Shells Weight lbs. 22 12

Contains powder oz. 12½ 9

Powder for bursting oz. 10 7

The following Shells may also be fired from Guns.

Hand Grenades from 6 Prs.

4⅖ Shells ” 12 Prs.

5½ Shells ” 24 Prs.

8 Inch ” 68 Pr. Carronades.

Shells may likewise be thrown from guns to short distances, in cases of necessity, though the bore be not of a diameter sufficient to admit the shell. For this purpose the gun may be elevated to any degree that will retain the shell upon its muzzle, which may be assisted by a small line going from the lugs of the shell round the neck of the gun. To produce a greater effect, the space between the shell and the charge may be filled with wads or other substance.

Lombard.

Shells are likewise sometimes quilted into grape. See the word Shot.

For the method of proving shells. See Proof.

To find the Weight of a Shell of Iron.

Take ⁹/₆₄ of the difference of the cubes of the external and internal diameters for the weight of the shell.

To find how much Powder will fill a Shell.

Divide the cube of the internal diameter of the shell in inches by 57.3, for the pounds of powder.

To find the size of a Shell to contain a given Weight of Powder.

Multiply the pounds of powder by 57.3, and the cube root of the product will be the diameter in inches.

The Germans do not name their shells from the diameter of the bore which receives them, but from the weight of a stone ball that fits the same bore as the shell. Thus a 7 lbs. howitzer admits a stone ball of that weight; the shell for this weighs 15 lbs. and answers to the English 5½ inch. The 30 lbs. howitzer shell weighs 60 lbs. and is rather more than 8 inches in diameter.

Note.—Shells were till lately made thicker at the bottom than at the fuze hole; but are now cast of the same thickness throughout, and are found to burst into a greater number of pieces in consequence.

SHOT.—Rules for finding the Number in any Pile.

Triangular Pile.

Multiply the base by the base + 1, this product by the base + 2, and divide by 6.

Square Pile.

Multiply the bottom row by the bottom row + 1, and this product by twice the bottom row + 2, and divide by 6.

Rectangular Piles.

Multiply the breadth of the base by itself + 1, and this product by 3 times the difference between the length and breadth of the base, added to twice the breadth + 1 and divide by 6.

Incomplete Piles.

Incomplete piles being only frustrums, wanting a similar small pile on the top, compute first the whole pile as if complete, and also the small pile wanting at top; and then subtract the one number from the other.

Rules for finding the Dimensions and Weight of Shot.

The weight and dimensions of shot or shells might be found by means of their specific gravities; (see the word Gravity;) but they may be found still easier, by means of the experimented weight of a ball of a given size, from the known proportion of similar figures, namely as the cubes of their diameters.

1st. To find the Weight of an Iron Ball from its Diameter—An iron ball of 4 inches diameter weighs 9 lbs. and the weights being as the cubes of their diameters, it will be as 64, (the cube of 4,) is to 9, so is the cube of the diameter of any other ball to its weight.

2d, To find the Weight of a Leaden Ball.—A leaden ball of 4¼ inches diameter weighs 17 lbs. Therefore, as the cube of 4¼ is to 17, (as 9 to 2 nearly,) so is the cube of the diameter of any leaden ball to its weight.

3d, To find the Diameter of an Iron Ball.—Multiply the weight by 7¹/₉ and the cube root of the product will be the diameter.

4th, To find the Diameter of a Leaden Ball.—Multiply the weight by 9, and divide the product by 2; and take the cube root of the quotient for the diameter.

Table of Diameters of English Iron Round Shot.

Nature. 68 42 32 24 18 12 9 6 3 1

Inches. 8. 6.684 6.105 5.547 5.040 4.403 4.000 3.498 2.775 1.92

Diameters of French Iron Round Shot in English Inches.

Nature. 36 24 16 12 8 7

Inches. 6.648 5.808 5.074 4.610 4.027 3.196

Table of English Case Shot for different Services.

Sea Service. Carronades.

Nature. Weight of each Shot. Number in each Case. Weight of each Case filled. Nature. Weight of each Shot. Number in each Case. Weight of each Case filled.

Prs. oz. Nᵒ. lbs. oz. Prs. oz. Nᵒ. lbs. oz.

32 8 70 33 8 68 8 90 46 2

24 8 42 22 15 42 8 66 32 8

18 6 42 16 8 32 8 40 21 4

12 4 42 11 5 24 8 32 16 1

9 3 44 8 9 18 6 31 12 2

6 2 40 5 2 12 4 32 8 2

4 2 28 4 — Tier Shot for Field Service.

3 2 20 2 15

1 1¼ 12 2 2¼

Common Land Service. oz. Nᵒ. lbs. oz.

12 Pr. 18 15 18 8

Med. 6½ 42 17 11

Prs. oz. Nᵒ. lbs. oz. 6 Pr. 8½ 15 9 —

24 4 84 21 11 Med. 3½ 42 8 14

12 2 84 12 1 3 Pr. 4½ 15 4 10

6 1½ 55 5 10½ Med. 1½ 42 4 6

12 Pr. 14 12 14 14

Light 6½ 34 14 11

6 Pr. 8½ 12 7 3

Light 3½ 34 7 7

3 Pr. 4½ 12 3 10

Light 1½ 34 3 11

For Mortars. Howitzers.

Nature. Weight of each Shot. Number in each Case. Weight of each Case filled. Weight of each Shot. Number in each Case. Weight of each Case filled.

Inch. oz. Nᵒ. lbs. oz. oz. Nᵒ. lbs. oz.

10 8 170 91 8 — — — —

8 6 90 38 4 6 90 33 8

5½ 3 55 12 6 3 55 12 8

4⅖ 2 55 8 1¼ 2 55 8 2

Table of Grape Shot, for Sea and Land Service.

Nature. Weight of each shot. Total Weight of the grape complete.

lbs. oz. lbs. oz.

42 Pounders. 4 0 46 6

32 ” 3 0 34 1

24 ” 2 0 25 5

18 ” 1 8 19 15½

12 ” 1 0 10 15

9 ” 0 13 7 6

6 ” 0 8 5 8½

4 ” 0 6 3 14½

3 ” 0 4 2 10½

½ ” 0 ⅗ lead 8¾

Small shells, as 4⅖ inches, and hand grenades were quilted into grape for 13 inch mortars at Gibraltar. The fuzes were turned inwards next the iron tampion, and leaders of quick match for communicating fire to the fuzes were introduced through holes made in the wood bottom, and placed as near the fuzes as possible in the center of the grape. These answered very well for short ranges.

Shand.

Hot Shot.—The powder for firing with hot shot must be in strong flannel cartridges, without any holes, lest some grains should remain in the bore, in putting the cartridge home. Over the powder must be rammed a good dry wad, then a damp one, and then the hot shot; and if the gun lays at a depression, there must be a wad over the shot, which may be rammed home. If the above precautions be attended to, the gun may be pointed after being loaded, without the smallest danger; as it is well known that the shot will grow cold in the gun, without burning more than a few threads of the wads next it. This is not the mode usually taught of loading with hot shot, but is that which was practised during the siege of Gibraltar. Mr. Durtubie proposes putting the shot when heated, into a tin cannister, as an effectual method of preventing accidents.

The grates usually made for heating shot will generally make them red hot in ¾ of an hour.

SINES.—See table of Natural Sines, at the end of the word Gunnery.

SOUND.—The medium velocity of sound is nearly at the rate of a mile, or 5280 feet; in 4⅔ seconds; or a league in 14 seconds; or 13 miles in one minute.—But sea miles are to land miles nearly as 7 to 6: therefore sound moves over a sea mile in 5¾ seconds nearly; or a sea league in 16 seconds.

Hutton.

Sound flies 1142 feet in one second.

Flamestead.

It is a common observation, that persons in good health have about 75 pulsations at the wrist in a minute, consequently in 75 pulsations sound flies about 13 land miles, or 11¹/₇ sea miles, which is about 1 land mile in 6 pulsations, and 1 sea mile in 7 pulses; or a league in 20 pulses.

Hutton.

The velocity of sound does not very much vary, whether it goes with the wind or against it. As sound moves vastly swifter than the wind, the acceleration it can thereby receive can be but inconsiderable; and the chief effect we can perceive from the wind is, that the sound will be carried to a greater distance by it. Sound will be louder in proportion to the condensation of the air. Water is one of the greatest conductors of sound: it can be heard nearly twice as far as on land.

Hutton.

STOPPAGES.—There shall be stopped out of the pay of an artillery soldier, (beer money included,) the sum of 5 shillings and one penny per week, to be applied towards the expense of his mess, (including vegetables, &c.) A sum not exceeding one shilling and six-pence per week shall be retained for necessaries to be accounted for, as usual, monthly. The remainder amounting to 3s. 10¾d. per week, shall be paid to the soldier, subject to the accustomed deductions for washing, &c. or articles for cleaning his cloaths and appointments. Stoppages for rations for man and horse. See the word Ration.

T angent—See the table of natural tangents at the end of the word Gunnery.

Tangent Scale.—.21 of an inch is the tangent of 1 degree to every foot of a gun’s length, from the base ring to the swell of the muzzle: Therefore if the distance in feet, between these two points be multiplied by .21, the product will be the tangent of 1 degree; from which the dispart being subtracted, will give the length of the tangent scale above the base ring for one degree of elevation for that particular gun. If the scale is to be applied to the quarter sight of the gun, of course the dispart need not be subtracted.

Tangent of 1 Degree to the following Ordnance.

Length. Tangent, 1° Dispart.

Feet. In. Inches. Inches.

12 Pr. Medium 6 6 1.365 1.475

12 Pr. Light 5 — 1.05 1.

6 Pr. Heavy 7 — 1.47 1.32

6 Pr. Light 5 — 1.05 1.

3 Pr. Heavy 6 — 1.26 1.08

10 Inch Howitzer 3 11½ .84 —

8 ” ” 3 1 .64 —

5½ ” Light 2 2¾ .47 —

4⅖ ” ” 1 10 .384 —

Tangent of 1 Degree to the following French Guns.

Nature of Ordnance. Siege. Field.

Tangent of 1° Dispart. Tangent of 1° Dispart.

In. Li. P. In. Li. P. In. Li. P. In. Li. P.

24 Pounder 2 1 5 1 2 4 — —

16 ” 2 — — 1 1 — — —

12 ” 1 10 6 1 — — 1 4 — 1 3 2

8 ” 1 8 3 1 — — 1 2 — 1 2 —

4 ” — — 1 — — 1 — —

6 In. How’r. — — 0 5 6 —

As the French tangent scales are marked off in inches and lines, the above dimensions are given in the same, for the more ready turning the French elevations into degrees, and thereby comparing their ranges with the English.

TENT for Laboratory Works.—Weight complete with poles, pins, &c. 3 cwt. 24 lbs. length of ridge pole, 18 feet; length of poles, 14½ feet.

Bell Tent, now used for infantry or cavalry; weight, complete with poles, 43 lbs. length of pole, 9 feet, contain 12 men each, require 40 pegs.

Common Infantry Tent.—Length of ridge pole 7 feet; length of standards 6 feet. They hold only 5 men each. Weight complete 27 lbs.

Marquee.—Weight complete,1 cwt. 17 lbs. ridge pole, 7 feet; standard, 8 feet.

TONNAGE.—The usual method of finding the tonnage of any ship is by the following rule: Multiply the length of the keel by the breadth of the beam, and that product by half the breadth of the beam; and divide the last product by 94, and the quotient will be the tonnage.

Ship’s keel 72 feet: breadth of beam 24 feet.

(72 × 24 × 12) = 220.6 tonnage.

94

The tonnage of goods and stores is taken sometimes by weight and sometimes by measurement; and that method is allowed to the vessel, which yields the most tonnage. In tonnage by weight, 20 cwt. make 1 ton. In tonnage by measurement 40 cubic feet equal 1 ton. All carriages, or other stores to be; measured for tonnage, are taken to pieces, and packed in the manner which will occupy the least room on board ship. All ordnance, whether brass or iron, is taken in tonnage by its actual weight. Musquet cartridges in barrels or boxes; all ammunition in boxes; and other articles of great weight are taken in tonnage, according to their actual weight.—See also the word Embarkation.

The following is the tonnage required for some of the most material ordnance stores.

Tonnage of Ordnance.

Nature. Nᵒ. T. ct. qr.

Axes, complete with handles Pole 264 — 10 0

Pick 100 — 9 0

Felling 176 — 14 0

Barrows— Wheel packed 20 2 2 0

” unpacked 7 1 0 0

Hand, single 20 0 18 0

Budge barrels 32 1 0 0

Bricks 1000 2 5 0

Buckets of leather 20 0 2 0

Pontoon and carriage complete, with its appurtenances 11 0 0

Carbines.— A chest with 25 stand is 11 feet cubic

Carriages.— Standing 42 Prs. 1 13 0

32 Prs. 1 10 0

Howitzer 10 Inch. 1 10 0

24 Prs. 1 9 8

Howitzer 18 Prs. 1 7 0

8 Inch.

12 Prs. 1 4 0

9 Prs. 1 3 0

6 Prs. 1 0 0

4 Prs. 0 17 0

Carriages.—Travelling, complete with limber boxes, ladles, sponges and rammers 24 Prs. 5 10 0

12 Prs. 4 10 2

9 Prs. 4 7 2

6 Prs. 3 7 2

3 Prs. 2 19 0

Medium 24 Prs. 2 9 2

12 Prs.

6 Pr. light, with ammunition boxes 2 3 0

5½ Inch howitzer, ” ”

5½ Howitzer of 10 cwt. Carriages 3 2 0

8 Inch Howitzer 3 7 2

Sling cart, complete 3 0 2

Forge cart, with limber 4 0 0

Ammunition waggon 4 18 1

Gravel cart 2 16 2

Duke of Richmond’s close bodied waggon 5 0 0

Road waggon, with upright sides 7 10 0

Gin; triangle 0 14 0

Grate for heating shot 0 4 2

Handspikes 120 1 0 0

Handcrow levers, of 5 feet 120 1 0 0

Handscrews, large 15 1 0 0

small 17 1 0 6

Helves, pick or felling 300 0 14 0

” sledge 300 1 0 0

” pinmaul 360 1 0 0

Junk 20 cwt. 1 5 0

Linstocks, without cocks 1000 1 0 0

with cocks 600 1 0 0

Musquets.— A chest with 25 is 16 feet.

” ” with 20 is 11 feet.

Match 6 cwt. 1 14 0

Powder 11 whole barrels 1 0 0

22 half” 1 0 0

Pitch or tar.—1 barrel is 7 feet.

Pistols.—A chest with 50 or 60 = 10 feet.

Park pickets 40 0 9 1

Pikes 12 dozen 1 1 0

Sheep Skins 280 1 0 0

Shovels of iron 100 1 0 0

Shovels, shod with iron 138 1 0 0

Sand bags Bales Bushel 500 0 12 0

½ ” 500 0 7 1

2 Bushel 250 0 8 1

The following is the tonnage allowed to the military officers of the ordnance embarked for foreign service, for their camp equipage and baggage:

For a field officer 5 tons.

For a captain 3 ”

For a subaltern 1½ ”

12th June, 1799.

TRANSPORTS.—See the word Embarkation.

TRENCHES.—A general term for all the approaches at a siege of a fortified place.

The approaches at a siege are generally carried on upon the capitals of the works attached; because the capitals produced are of all other situations in the front of a work the lead exposed to the fire of either the cannon or musquetry; and are the least in the line of fire between the besieged and besieger’s batteries. But if, from particular circumstances, these, or other advantages do not attend the approaches upon the capitals, they are by no means to be preferred to other positions.

The trenches of communication, or zig-zags, are 3 feet deep, 10 feet wide at bottom, and 13 feet at top, having a berm of one foot, beyond which the earth is thrown to form a parapet.

The parallels or places of arms of the trenches are 3 feet deep, 12 feet wide at bottom, and 17 or 18 feet wide at top, having a banquette of about 3 feet wide, with a slope of nearly as much. See the word Sap.

The first night of opening the trenches, the greatest exertions are made to take advantage of the enemy’s ignorance as to the side of attack; and they are generally carried on as far in advance as the first parallel, and even sometimes to the completion of that work. The workmen set out on this duty, each with a fascine of 6 feet, a pick ax, and a shovel; and the fascines being laid so as to lap one foot over each other, leaves 5 feet of trench for each man to dig.

The usual method of directing the trenches or zig-zags, is by observing during the day some near object in a line with the salient parts of the work, and which may serve as a direction in the night; or if the night be not very dark, the angles of the works maybe seen above the horizon; but as both these methods are subject to uncertainty, the following is proposed, to answer every case: having laid down the plan of attack, the exact positions of the flanked angles of the works of the front attacked, and particularly of those most extended to the right and left, mark on the plan the point of commencement for the first portions of zig-zag; the point where it crosses the capital; and the point to which it extends on the other side of the capital: this last point will be the commencement of the second branch; then mark off the point where this branch crosses the capital and its extent on the other side; and this will give the commencement of the third branch; and so on for the others. Thus provided with a plan ready marked off, it will be very easy, even in the darkest night, to lay down the points where the zig-zags are to cross the capital, and the points to which they are to be produced beyond them. The first parallel is generally run about 600 yards from the place, and of such extent as to embrace the prolongations of the faces of all the works which fire upon the trenches; and each end has a return of about 30 or 40 yards.

The second parallel is constructed upon the same principles, and of the same extent as the first; at the distance of about 300 yards from the salient angles of the covert way. This parallel is usually formed of gabions, each workman carrying a gabion, a fascine, a shovel, and a pick ax. After this the trenches are usually carried on by sap.—See that word.

The half parallels are about 140 or 150 yards from the covert way, and extend on each side sufficient to embrace the prolongation of the branches of the covert way.

The third parallel must not be nearer than the foot of the glacis, or it will mask the ricochet batteries. It is generally made rather wider than the other parallels.

Cavaliers of the trenches must not be nearer than 28 yards from the covert way, or they will be liable to be annoyed by hand grenades.

See likewise the words Approaches, Sap, and Battery.

TROU DE LOUP—A cone reversed. Diameter of the base 4 feet 6 inches; depth 6 feet; picket 6 feet long, and from 4 to 5 inches square; contain ¾ of a cubic fathom of earth, and are usually placed 2 in 3 fathoms.

TUBES—of tin plates are the best for service. Tubes must pass through a gauge of ²/₁₀ of an inch diameter. The composition is mealed powder, mixt up stiff with spirits of wine. They are made up in bundles of 100 each.

Length of Tin Tubes.

Length. Nature of Ordnance.

Heavy. Medium. Light. Howitzer. Land Mortars. Sea Mortars.

Inches. Pr. Pr. Pr. Inch. Inch. Inch.

12.2 — — — — — 13

8.8 24 24 — — — —

8.2 18 18 — — — —

7.75 12 12 — — 13 10

6.8 9 9 — — — —

6.5 6 — 24 8 10 —

5.9 3 6 12 5½ — —

5.0 — — — — 8 —

4.75 1½ 1½ 6 — — —

4.2 — — — 4⅖ 5½ —

3.6 — — — — 4⅖ —

Note.—If tin tubes get damaged by wet, the composition may be cleared out of them, and they may be fresh filled. If spirits of wine cannot be had, good rum or brandy will answer the purpose.

U niforms—

Principal Colour of the Military Uniforms of the different Powers of Europe.

NATIONS. Cavalry. Infantry. Artillery. Remarks.

Imperial White White Grey

Russian Blue Green Green Black cockades.

Danes — Red —

English Blue Red Blue

French Blue White Blue Nati’l. cockades.

Poland Blue Blue Blue

Prussian White Blue Blue Drag. light blue.

Sardinian Blue Blue Blue

Sweden — Blue — Yellow cockades.

Bavaria — White Grey

Hanover Blue Red mixt Blue Green cockades.

Mayence — White ”

Palatine Crimson clear Blue —

Saxon White White Green Dragoons red; white cock.

Anspach Blue Blue Blue

Bade — Blue —

Brunswick — Blue —

Hesse White Blue Blue

Nassau Sarlz — Blue —

Saxe Cobourg — Blue —

Saxe Gotha Blue Blue Blue

Saxe Hildburg — Blue —

Saxe Meemingen — Blue —

Saxe Weimer Blue Green Green

Wurtemburg — Blue Blue

Holland White Blue Blue

Berne Red Blue Blue Black and red cockades.

Mecklenburg Blue Blue Blue

V elocity—Initial velocity of military projectiles, as ascertained by the experiments with the Ballistic pendulum at Woolwich, in 1788, 1789, and 1790. These experiments were made with shot of equal diameters, powder of equal strength, and under a mean height of the barometer; and shew,

1. That there is very little difference in the velocities of shot fired from guns of the same length, but of unequal weights; the advantage being sometimes in favour of one and sometimes of the other.

2. That velocities arising from firing with different quantities of powder, are nearly in the proportion of the square roots of the quantities or weights of powder.

3. That the velocities decrease as the distances increase, arising from the resistance of the air, which opposes the progress of the shot, in a proportion somewhat higher than the squares of the velocities throughout; and only to a small variation.

4. That very little advantage is gained in point of range, by increasing the charge more than is necessary to attain the object, the velocities given by large charges being very soon reduced to those by moderate charges: those for instance given by half the shot’s weight are reduced to an equality with those by one third, after passing through a space of only 200 feet.

5. That very little advantage is also gained by increasing the length of guns; the velocity given by long guns of 22 calibers length of bore, being reduced to an equality with those of the short guns of 15½ calibers with similar charges, after passing through the spaces as follows:

With ½ the shot’s weight 285 feet.

⅓ ” ” 200

¼ ” ” 150

⅙ ” ” 115

6. That the resistance of the air against balls of different diameters with equal velocities, is very nearly in the proportion of the squares of their diameters; or as their surfaces.

7. That the velocity is not affected by compressing the charge more or less; or by heating the piece in different degrees.

8. That a very great increase of velocity arises from a decrease of windage; it appearing, that with the established windage; of ¹/₂₀ between ⅓ and ¼ of the force is lost.

9. It also appeared, that by firing the charge in different parts; by varying the weight of the gun to lessen the recoil; or even by stopping the recoil entirely, no sensible change is produced in the velocity of the ball.

10. That though the velocity of the shot is increased only to a certain point peculiar to each gun, (a further increase of powder producing a diminished velocity,) yet the recoil of the gun is always increased by an increase of charge.

11. Velocity of a light 6 Pr.—length, 4 feet 8 inches; charge, ⅓ the weight of the shot; 1558 feet per second.—6 Prs. heavy; 6 feet 8 inches; charge ⅓ = 1673 feet.

Velocity of a light 3 Pr. length, 3 feet 4 inches, charge ⅓—1371 feet per second.

Do. Heavy 3 Pr. length, 5 feet 9½ inches, charge ⅓ the shot—1584 feet.

Hutton.

Velocity of French Ordnance.

24 Pr. charge 8 lbs. the eprovette mortar giving 125 fathoms, the initial velocity is 1425 feet per second; with the eprovette at 90 = 1209 feet; with a charge of 12 lbs. and the eprovette at 125; the initial velocity will be 1530.

Charge. Eprovette. Velocity.

16 Pr. 5 lbs 125 1415

” ” 8 ” 1510

12 Pr. 4 ” long guns 1520

8 Pr. 2½ ” 1418

” ” 3 ” 1460

4 Pr. 1 ” 1335

” ” 1½ ” 1508

12 Pr. 4 ” field guns 1442

8 Pr. 2½ ” 1422

4 Pr. 1½ ” 1446

8 Inch How’r. 1 ” 390

” ” ” 1 2 oz. ” 516

6 Inch How’r. 1 ” 532

” ” ” 1 12 ” 704

Lombard’s Tables.

VENT.—The vents of English guns are all ²/₁₀ of an inch diameter.—See remark 9 of the article Velocity.

W eights—See Measures.

WINDAGE.—The usual windage of English guns is ¹/₂₀ of the caliber. It appears by experiments, that ¼, or nearly ⅓ of the force of the powder is lost by this windage.—See remark 8 of the word Velocity.

Windage of Guns and Carronades.

Natures. 68 42 32 24 18 12 9 6 4 3 2 1

Guns — .33 .30 .27 .25 .22 .20 .17 .15 .14 .12 .09

Carrona. .15 .15 .15 .14 .12 .12

Windage of Mortars and Howitzers.

From the 13 to 5½ inch the windage is .15 of an inch, and that of the 4⅖ is .2 of an inch.

Windage of French Guns.

Field Guns.—All one line of windage; about ¹/₅₀ in an 8 pounder.

Siege Guns.—All 1½ line; about ¹/₄₈ in a 24 Pr.

Mortars.— 12 Inch; 4 lines of windage.

10 Inch; 1 line, 5 points ”

8 Inch; 1 line, ”

Howitzers.— All; 2 lines ”

WOOD.—Artillery carriages are generally made of elm, ash, and oak. The bed and house of a sea mortar are made of oak, and the bolster of elm. The bottoms of land mortar beds are of oak, and the upper parts of elm.

Carriages— Ship.— The cheeks, transoms, and trucks of elm;

the axle trees of oak.

” Garrison.— The whole of oak; trucks, iron.

” Field.— Heavy 24 and 12 Pr. the cheeks and

transoms of elm; the axle trees of ash.

In the wheel the nave and fellies are

of elm; the spokes of ash; limber

shafts, bars, and axle trees are of

ash. Light guns, from 3 to 12 Prs. the

cheeks and transoms are of elm; the

ammunition boxes are of fir. In the

wheels, the nave is of elm, the spokes

of oak, and the fellies of ash. In the

limber the shafts and bars of ash.

THE END.

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