[9]The French weights and measures have assumed new names, and are reduced to strict proportions since the revolution. The weights here referred to are the old. For the new French system of weights and measures, see the wordWeights.
[9]The French weights and measures have assumed new names, and are reduced to strict proportions since the revolution. The weights here referred to are the old. For the new French system of weights and measures, see the wordWeights.
Length and weight of English iron guns.
[10]This column expresses the number of English pounds of metal in the guns, to each pound in the shot.
[10]This column expresses the number of English pounds of metal in the guns, to each pound in the shot.
French iron guns, in English weights, &c.
Ranges of brass guns, with one shot. 1793.
Ranges from Brass Guns, with Two Shot. 1793.
Ranges from Brass Field Guns, with small charges. 1798.
N. B. The above was a 12 Pr. Medium, and a 6 Pr. Desagulier’s. The distances are given in yards.
Effects of case shot from a battalion gun—Light 6 Pr. length 5 feet—Weight 5 cwt. 3 qrs. 21 lbs. against a target 8 feet high, and 90 feet long.
N. B. There were three rounds fired at each charge, but they were all so nearly alike, that it has been thought necessary to put down only one of them. 1802.
Ranges with sea service iron guns. 1796.
Ranges with 5¹⁄₂ inch shells, from a 24 Pr. iron Gun. Length of Gun 9¹⁄₂ ft. Wt. 49 ct. 26lb.
Ranges with 4²⁄₅ Shells from a 12 Pounder, Medium.
Ranges with French brass field guns, with round shot.
The above are in old French weights and measures.
Definitions ofGunnery. 1. The impetus at any point of the curve is the perpendicular height to which a projectile could ascend, by the force it has at that point; or the perpendicular height from which a body must fall to acquire the velocity it has at that point.
2. The diameter to any point of the curve is a line drawn through that point perpendicular to the horizon.
3. The points where the diameters cut the curve are called vertexes to these diameters.
4. The axis is that diameter which cuts the curve in its highest or principal vertex, and is perpendicular to the tangent at that point or vertex.
5. The ordinates to any diameter are lines drawn parallel to the tangent at the point where that diameter cuts the curve, and intercepted between the diameter and curve.
6. The absciss is that part of the diameter which is intercepted between the ordinate and the curve.
7. The altitude of the curve is the perpendicular height of the principal vertex above the horizon.
8. The amplitude, random, or range, is the distance between the point of projection and the object aimed at.
9. The elevation of the piece is the angle its axis (produced) makes with the horizon, and the axis itself is called the direction.
10. The horizontal distance to which a mortar, elevated to a given angle, and loaded with a given quantity of powder, throws a shell of a given weight, is called the range of that mortar, with that charge and elevation.
11. The inclination of a plane is the angle it makes with the horizon either above or below.
12. The directrix is the line of motion, along which the describing line or surface is carried in the genesis of any plane or solid figure.
Laws of motion inGunnery.
1. Spaces equally run through with equal velocities, are to one another as the times in which they are run through, and conversely.
2. Spaces equally run through in the same or equal times, are to one another as the velocities with which they are run through, and conversely.
3. Spaces run through are in the same proportion to one another, as their times multiplied into their velocities, and conversely.
4. A body urged by two distinct forces in two different directions, will in any given time be found at the point where two lines meet that are drawn parallel to these directions, and through the points to which the body could have moved in the same time, had these forces acted separately.
5. The velocities of bodies, which by the action of gravity begin to fall from the rest, are in the same proportion as the times from their beginning of their falling.
6. The spaces run through by the descent of a body which began to fall from rest, are as the squares of the times, from the beginning of the fall.
7. The motion of a military projectile is in a curve.
Gun-powder, a composition of nitre, sulphur, and charcoal, well mixed together and granulated, which easily takes fire, and expands with amazing force, being one of the strongest propellents known.
Gun-powder.—Proportions of the different ingredients for making gunpowder, by different powers in Europe:
Gunpowder.This well known powder is composed of seventy five parts, by weight, of nitre, sixteen of charcoal, and nine of sulphur, intimately blended together by long pounding in wooden mortars, with a small quantity of water. This proportion of the materials is the most effectual. But the variations of strength in different samples of gunpowder are generally occasioned by the more or less intimate division and mixture of the parts. The reason of this may be easily deduced from the consideration, that nitre does not detonate until in contact with inflammable matter; whence the whole detonation will be more speedy, the more numerous the surfaces of the contact. The same cause demands, that the ingredients should be very pure, because the mixture of foreign matter not only diminishes the quantity of effective ingredients which it represents, but likewise prevents the contacts by its interposition.
The nitre of the third boiling is usually chosen for making gunpowder, and the charcoal of light woods is preferred to that of those which are heavier, most probably because this last, being harder, is less pulverable. An improvement in the method of making the charcoal has lately been adopted, which consists in putting the wood, cut into pieces about nine inches long, into an iron cylinder laid horizontally, closed at one end, and furnished with small pipes at the other, that the pyroligneous acid and carburetted hidrogen may escape, and thus exposed to the heat of a fire made underneath. It is said, this charcoal improves the strength of gunpowder so much, that only two thirds of the old charge of gunpowder for ordnance are now used in our navy. The requisite pounding of the materials is performed in the large way by a mill, in which wooden mortars are disposed in rows, and in each of which a pestle is moved by the arbor of a water-wheel: it is necessary to moisten the mixture from time to time with water, which serves to prevent its being dissipated in the pulverulent form, and likewise obviates the danger of explosion from the heat occasioned by the blows. Twelve hours pounding is in general required to complete the mixture; and when this is done, the gunpowder is in fact made, and only requires to be dried to render it fit for use.
Proofs of powder.—The first examination of powder in the British mills, is by rubbing it in the hands to find whether it contains any irregular hard lumps. The second is by blasting 2 drams of each sort on a copper plate, and in this comparing it with an approved powder; in this proof it should nor emit any sparks, nor leave any beads or foulness on the copper. It is then compared with an approved powder, in projecting an iron ball of 64 lbs. from an 8 inch mortar, with a charge of 2 ounces. The best cylinder powder generally gives about 180 feet range, and pit 150; but the weakest powder, or powder that has been redried, &c. only from 107 to 117 feet.
The merchants’ powder, before it is receivedinto the government service, is tried against powder of the same kind made at the royal mills; and it is received if it gives a range of ¹⁄₂₀ less than the king’s powder with which it is compared. In this comparison both sorts are tried on the same day, and at the same time, and under exactly the same circumstances.
The proof of fine grained, or musquet powder, is with a charge of 4 drams from a musquet barrel, to perforate with a steel ball a certain number of ¹⁄₂ inch wet elm boards, placed ³⁄₄ inch asunder, and the first 39 feet 10 inches from the barrel: the king’s powder generally passes through 15 or 16, and restoved powder from 9 to 12. The last trial of powder is by exposing about 1 pound of each sort, accurately weighed, to the atmosphere for 17 or 18 days; during which time, if the materials are pure, it will not increase any thing material in weight, by attracting moisture from the atmosphere.
In this exposure 100 lbs. of good gunpowder should not absorb more than 12 oz. or somewhat less than one per cent.
Different modes of trying gunpowder have been adopted. A ready one is, to lay two or three small heaps on separate pieces of writing paper, and fire one with a red hot wire. If the flame ascend quickly, with a good report, leaving the paper free from white specks, and not burnt into holes; and at the same time the other heaps be not fired by the sparks, the powder is well made, and the ingredients are good.
There are experiments which seem to show, that gunpowder is stronger in the fine impalpable form, than when granulated. This appears to be true with regard to gunpowder originally made, or pounded till it assumes that form; but it may be doubted, whether it have any foundation in general, or indeed that the greater strength depends at all upon this form.
British Powder Marks.—The different sorts of powder are distinguished by the following marks on the heads of the barrels.
L G or F G in blue, is powder made of pitcoal.
ThisredL G, F G, or S G, denotes powder entirely made of the cylinder charcoal, and is that which is now always used on service. The white L G being a mixed powder, is not so uniform as the other, and is therefore generally used in filling shells, or for such other purposes as do not require much accuracy. All powder for service is mixed in proportions according to its strength, so as to bring it as much as possible to a mean and uniform force.
French Gunpowder.—The French proof ball is of brass, and weighs 60 lbs. French: the diameter of the mortar 7 inches 9 points, or ³⁄₄ of a line, and has one line of windage. The chamber holds exactly 3 ounces; and their best powder must give a range of 90 toises, and their restoved powder a range of 80 toises, to be received into the service. But the powder they now make, when new, will give range of 100 and 120 toises; and Mr. Lombard calculates all his tables from experiments made with powder giving 125 toises with the eprouvette. The above dimensions and weights are all of old French standard.
Invention ofGun-powder, is usually ascribed to one Bartholdus Schwartz, a German monk, who discovered it about the year 1320; it is said to have been first used in war by the Venetians against the Genoese in the year 1380. Thevel says its inventor was one Constantine Anelzen, a monk of Friburg. Peter Mexia says it was first used by Alphonsus XI. king of Castile, in the year 1342. Ducange adds, that there is mention made of this powder in the registers of the chambers of accounts of France, so early as the year 1338; and friar Bacon, expressly mentions the composition in his treatiseDe Nullitate Magiæ, published at Oxford in the year 1216. Some indeed are of opinion, that the Arabians or the latter Greeks were the first inventors of gunpowder, about the middle ages of our æra; because its Arabic name is said to be expressive of its explosive quality.
Considerable improvements have lately been made in the composition of gunpowder by the Chinese.
Method of makingGunpowder. Take nitre, sulphur, and charcoal; reduce these to a fine powder, and continue to beat them for some time in a stone mortar with a wooden pestle, wetting the mixture occasionally with water, so as to form the whole into an uniform paste, which is afterwards reduced to grains, by passing it through a sieve; and in this form, being carefully dried, it becomes the common gunpowder. For greater quantities mills are used, by means of which more work may be performed in one day than a man can do in a hundred. SeeMill.
This destructive powder is composed of 75 parts nitre, 9 sulphur, and 16 of charcoal, in the 100.
The granulation of gunpowder is performed by placing the mass, while in theform of a stiff paste, in a wire sieve, covering it with a board, and agitating the whole: by this means it is cut into small grains or parts, which, when of a requisite dryness, may be rendered smooth or glossy by rolling them in a cylindrical vessel or cask. Gunpowder in this form takes fire more speedily than if it be afterward reduced to powder, as may be easily accounted for from the circumstance, that the inflamation is more speedily propagated through the interstices of the grains. But the process of granulation does itself, in all probability, weaken the gunpowder, in the same manner as it is weakened by suffering it to become damp; for in this last case, the nitre, which is the only soluble ingredient, suffers a partial solution in the water, and a separation in crystals of greater or less magnitude; and accordingly the surfaces of contact are rendered less numerous.
The detonation of gunpowder has been always an interesting problem in chemistry. Numerous theories have been offered, to account for this striking fact. But it is now very well settled, that the nitric acid is decomposed by the heat of ignition; that is oxigen, combines with the charcoal, and forms carbonic acid, while the nitrogen, or other component part, with steam from the water of crystallization, becomes disengaged in the elastic form. Berthollet found, that the elastic product, afforded by the detonation of gunpowder, consisted of two parts nitrogen gas, and one carbonic acid gas. The sudden extrication and expansion of these airs are the cause of the effects of gunpowder.
The muriat afforded by combining the oxigenized muriatic acid and potash, affords gunpowder of much greater strength than the common nitre, but too dangerous for use. For the method of making this salt, SeeAcid (Muriatic, oxigenized).
How to refine nitre.Put into a copper, or any other vessel, 100 weight of rough nitre, with about 14 gallons of clean water, and let it boil gently for half an hour, and as it boils take off the scum; then stir it about in the copper, and before it settles put it into your filtering-bags, which must be hung on a rack, with glazed earthen pans under them, in which sticks must be laid across for the crystals to adhere to: it must stand in the pans for two or three days to shoot; then take out the crystals and let them dry. The water that remains in the pans boil again for an hour, and strain it into the pans as before, and the nitre will be quite clear and transparent; if not, it wants more refining; to effect which proceed as usual, till it is well cleansed of all its earthy parts.
How to pulverize nitre.Take a copper kettle, whose bottom must be spherical, and put into it 14lb, of refined nitre, with 2 quarts or 5 pints of clean water; then put the kettle on a slow fire; and when the nitre is dissolved, if any impurities arise, skim them off; and keep constantly stirring it with 2 large spattles till all the water exhales; and when done enough, it will appear like white sand, and as fine as flour; but if it should boil too fast, take the kettle off the fire, and set it on some wet sand, by which means the nitre will be prevented from sticking to the kettle. When you have pulverised a quantity of nitre, be careful to keep it in a dry place.
Different kinds ofGunpowder. It being proper that every one who makes use of gun-powder should know of what it is composed, we shall give a brief account of its origin and use. Gunpowder, for some time after the invention of artillery, was of a composition much weaker than what we now use, or than that ancient one mentioned by Marcus Græcus: but this, it is presumed, was owing to the weakness of their first pieces, rather than to their ignorance of a better mixture: for the first pieces of artillery were of a very clumsy, inconvenient make, being usually framed of several pieces of iron bars, fitted together lengthways, and then hooped together with iron rings; and as they were first employed in throwing stone shot of a prodigious weight, in imitation of the ancient machines, to which they succeeded, they were of an enormous bore. When Mahomed II. besieged Constantinople in the year 1453, he battered the walls with stone bullets, and his pieces were some of them of the calibre of 1200lb. but they never could be fired more than four times in the 24 hours, and sometimes they burst by the first discharge. Powder at first was not grained, but in the form of fine meal, such as it was reduced to by grinding the materials together; and it is doubtful, whether the first grain of it was intended to increase its strength, or only to render it more convenient for the filling it into small charges, and the loading of small arms, to which alone it was applied for many years, whilst meal-powder was still made use of in cannon. But at last the additional strength, which the grained powder was found to acquire from the free passage of the fire between the grains, occasioned the meal-powder to be entirely laid aside. The coal for making gunpowder is either that of willow or hazle; but the lightest kind of willow is found to be the best, well charred in the usual manner, and reduced to powder. Corned powder was in use in Germany as early as the year 1568; but it was first generally used in England in the reign of Charles I.