4. Springs and Wells.—Attend to the quality and quantity of the water; whether it will serve for the cavalry, as well as infantry, and the manner of its being drawn. Observe the situation of the spring, and of its source, whether it can be protected, and the enemy prevented from cutting it off.

5. Lakes, Marshes, and Swamps.—Learn their cause; if arising from a moist soil, the overflowings of rivers or from springs. Observe their situation, and the appearance of the surrounding country; the best means of crossing them. If they are divided by causeways, notice their breadth and condition; if not, remark if causeways can be easily established, and whether the swamp can be drained, and whether it is passable at any season of the year. Observe the points from which the causeways can be defended against the passage of an enemy’s column. Learn whether or not the swamps are subject to fogs; and at what seasons they are most hurtful.

6. Of Woods and Forests.—Remark their extent; their situation; their thickness; whether the trees are lofty or low; whether there is much underwood. Observe if the different clumps form openings or passes; and their extent; whether their sides are formed of thick wood or brush; whether their breadth is uniform, or widens at particular parts. Remark whether the ground of the forest be level or hilly, swampy or dry. Observe the nature and condition of the roads (for remarks to be made on these, see the article Roads;) observe also the means the forest affords of intrenching; of making fascines, abbatis, &c. Attend to the face of the country round the forest, whether cultivated fields or meadows: whether it affords positions; is intersected by rivulets, swamps or ravines.

Remark the castles, villages, towns, &c. in the neighbourhood; and their distance from the skirts of the wood.

Go round the wood and examine its principal débouchés; observe the ravines, rivulets, roads, &c. issuing from it, and learn their direction.

7. Heaths.—Notice for what nature of troops they are best calculated. The nature of hedges and brush wood; some form a good breast work. Observe the directions of the rivulets, roads, and ravines. When the ground of a heath is of the common colour, the roads are usually good: but when it is blackish and mixed with white sand, the roads are generally impassable in winter seasons.

8. Canals.—For this article see also the observations on Rivers. Observe their intention; the nature of the soil in which they are dug, their breadth and depth; their locks; the craft found upon them; the best means of protecting or destroying them: learn the countries they pass through.

9. Rivers.—Learn in what country they arise, and where empty themselves; the nature of the countries they run through, and whether they belong to us or the enemy. Learn the extent to which they are navigable; and if they ever freeze over, whether strong enough to bear troops and carriages. Notice the quality of the water, its course, currents, depths, and breadths. The banks and the beds of the rivers. Observe the nature and number of the craft that navigate them; and the mills upon their banks, whether of wind or water. Visit the bridges and fords; and make the proper remarks on their nature and situation. Learn whether the rivers ever overflow their banks, and at what season; and whether or not this causes inundations. Observe the most favourable points for crossing, and the roads leading to these points. The turnings and windings of the rivers, the form of their peninsulas; and the most favourable situations for throwing over bridges. If there are any wharves on the banks, observe what craft can lay along side of them.

If there are islands in the rivers, note their size; their banks; whether inhabited, cultivated, woody, or barren; and whether they command the channel.

Observe the mountains and high grounds near the rivers; remark their distance from the banks, and the advantages, or disadvantages which they offer. Learn what branches or confluence of other rivers there are either above or below, the best situations for crossing. Examine the positions which the adjoining country affords an army to protect the passage of the river; and whether in a perpendicular or parallel direction; and the routes by which 3 or 4 columns may arrive at the place.

10. Passes.—Observe their breadth, their length, their situation; the nature of the adjacent country: the best positions to occupy to cover a retreat; or to dispute the pass. How the troops would be best arranged; and the number that would be required for this purpose.

11. Ravines, Vallies.—Observe the nature of the soil; whether rocky, or of loose flints. If the sides are rugged and steep, whether they can be easily scarped off. The points that command them: whether storms or floods are to be apprehended; and at what seasons most expected.

12. Cultivated Lands.—Notice their state of cultivation: their productions; their time of harvest. Learn what quantity of wheat, rye, barley, oats, or other grain they produce, over and above the necessary subsistance of the inhabitants. How much hay they yield per acre.

13. Orchards.—Observe whether they are thick planted and afford a good cover: their enclosures, whether hedge, ditches, walls, &c.

14. Bridges.—Remark their situation; their length and breadth; the materials of which they are built; their strength, whether sufficient to bear artillery: the roads leading to them: their situation, as to the turnings of the river: their purpose; if to connect towns or villages, the nature, direction, and breadth of the streets leading to them. Observe the country around, whether flat or commanding: study the best means of fortifying the bridge head; and observe the best and most expeditious mode by which the bridge may be destroyed, if necessary.

15. Mountains, Hills.—Amongst high mountains, such as the Alps, roads are very rare; it is seldom more than the vallies that are inhabited and accessible for troops: observe their slopes, if steep or rugged. Examine the positions; means of gaining the summits; and note the state of cultivation and general appearance of the vallies; the pasturage, forage, cottages, villages, castles, roads, paths, and passes. Distinguish the principal chains of hills and their direction. Their relative heights; whether they are sufficiently extensive to form a line of defence; their communications; their strong points; positions proper for batteries, &c. Whether practicable for cavalry and artillery.

16. Coasts.—Their nature; whether bordered by downs; surrounded by rocks, which render their approach dangerous; or by shoals, which make their access impracticable; note the points and headlands proper for forts and batteries to defend the anchorage, ports, harbours, or other accessible parts. If there are any adjacent isles, perhaps they will serve for the erection of advanced batteries, to form a barrier to the efforts of an enemy. Observe the nature of the shores, bays, roads for shipping, &c. with the winds required to go in and out the harbours; and whether they are of easy access: their advantages and disadvantages, their size and depth of water. If a river empties itself on the coast, observe the particular channel for shipping, and whether it can be defended by any of the batteries. If the coast is already fortified, observe all the batteries, forts, or intrenchments, established for its defence, and the protection of the anchorage, &c. Examine the camps and other military posts, which cover the principal points, and the interior of the country. Estimate all the dangers to be run, and all the obstacles to be overcome in a descent, and point out the means of augmenting them. Observe the time of the tide most favourable for approaching the coast. Ascertain the number of artillery and other troops constantly on the coast, and the force that can be collected at a short notice; and how soon they can be drawn to any particular point attacked. Examine the system of defence adopted, and endeavour to improve it.

17. Forts, Redoubts.—Remark their form, whether ancient or modern; whether they are permanent or temporary; elevated or low; revetted or demi-revetted, with stone, brick, or turf. Whether the ditch is wet or dry; fraized or palissaded; natural or artificial. Observe their situation; the face of the adjacent country; whether they effectually command the passes, or protect the country intended. The defence they are capable of making in their present state, and the improvements of which they are susceptible.

18. Castles, Citadels.—Their situation; their form; their extent; their object; the protection they give the city; their connection and communication with it. The present state of their defence, and the improvements of which they are susceptible. Their Souterraines.

19. Villages.—Observe their situation; ascertain the number of families they contain; the nature of the land; the quality and quantity of their crops; their markets; the suburbs that supply these markets; their beasts of burthen: their flocks, herds, poultry, &c. The number of their ovens; quality of the water; stile of houses, barns, stables, and sheep walks. The situation of the church; the nature of the church yard, and its enclosures. The wind and water mills. Observe whether the village is surrounded by hedges, ditches, banks, or walls; whether it can be easily intrenched. Its streets; roads leading to it; and the face of the surrounding country.

20. Cities not fortified.—Their situation; population; commerce; commodities; manufactures; the succours that may be drawn from them, as to men, horses, &c. Their squares and principal buildings. The defence they are susceptible of; whether they are surrounded by walls, old towers, ditches, &c. Their gates, and the roads leading to them. The face of the surrounding country.

21. Fortified Towns.—Their situation with respect to their position, and with respect to other towns in the neighbourhood, whether in the first or second line; the assistance which they can afford each other. The succours that may be drawn from them, or that may be thrown into them in case of a siege. The direction which such relief, whether of men or provisions, ought to take, according to the side attacked; whether they will serve as depots or hospitals. The state of the fortifications (see the word Fortification in the alphabet;) their nature; the strength of each front. The rivers in the neighbourhood; the surrounding country within the range of the guns. The form of investment; what lines will be required considering the nature of the country, and the positions; and the means the country affords of executing them. The advantages which the ground would afford between the glacis and the lines, either to the besiegers or besieged; the means of establishing the most certain communications between the different quarters of the army, and the means of cutting them off.

22. Positions.—Every military position ought to possess decided advantages of situation, and ought to be commanded in no part of its front, flank, or rear. All commanding grounds ought to be without the range of cannon. There are four principal objects to be attended to in the choice of a position: 1st. The advantages of the ground; 2d. The supplies for the army; 3d. The objects to be attained; and, 4th. The communications with the rear. The front of a position should be intersected by rivers, ravines, or broken ground, or any other obstacles which can prevent the enemy advancing in order of battle, and oblige him to pass through defilés; but a position becomes useless when the front is so covered by obstacles that the army cannot advance or move out of its camp when necessary; but no obstacles can be too great on the flanks. All obstacles which cover a position, or passes which lead to it, must be within the range of the artillery, or the enemy will pass them unmolested. In a flat country, where the ground does not afford commanding situations, a position is only more or less eligible, as being covered or protected by obstacles; these are very thick woods, in which there are very few roads; large rivulets which cannot be forded or passed without bridges; narrow roads; deep and broken ravines; ground much intersected with hedges, ditches, &c. but it is essential that all these obstacles should be under the fire of the artillery. It is always dangerous to occupy a position, which has its rear so covered by swamps, crossed by rivers or ravines, &c. as to render the retreat of the army difficult. The number of passes by which an army can retire must be examined and secured, and should never be less than 5 or 6. The rivers, brooks, &c. in front of a position, should never be depended upon for a supply of water, as the enemy may cut them off. The ground for a camp should not be too much intersected by hedges, ditches, or ravines, which occasion great intervals in the line, and obstruct the communications through the camp.

In an offensive position it is absolutely necessary that the army should not be too much confined by obstacles, but be at liberty to act in every direction; but in a defensive position, the fewer accessible points there are the better: and if the natural difficulties in front and flank are not sufficient to render an enemy’s attack dangerous, they must be increased by redoubts, intrenchments, abbatis, inundations, &c. The obstacles on the flanks, should also be of such extent that they cannot be easily turned, without the enemy makes a very great circuit; and consequently exposes his own flank, and weakens his line of communication. In case the enemy detaches a body to attack a defensive position in the rear; the front must be sufficiently strong to enable the general to oppose the enemy’s detachment, by a strong body from his own army. In short, the enemy must not be able by any manœuvre to force the army to quit its position. The want of wood or water, or other supplies absolutely necessary for an army, renders every other advantage of a position useless; nor, can a position be long tenable, that is far removed from its depots; and has not its intermediate posts perfectly secure from the attacks of an enemy. For further remarks upon positions, see the word Artillery in the Field.

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.

General Table of Sky Rockets.

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.

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.

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

The following Shells may also be fired from Guns.

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.

Diameters of French Iron Round Shot
in English Inches.

Table of English Case Shot for different Services.

Table of Grape Shot, for
Sea and Land Service.

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.