Part 127

PROGRAM, (_Programme_, _Fr._) a word derived from the Greek, signifying any public edict, notice, or declaration. The French make use or the word on occasions of national ceremony.

PROJECTILES, are such bodies as, being put in motion by any great force, are then cast off, or let go from the place where they received their quantity of motion; as a shell or shot from a piece of artillery, a stone thrown from a sling, or an arrow from a bow, &c. This line is commonly taken for a parabola, and the ranges are computed from the properties of the curves. The assumption would be just, in case the ball, in its motion, met with no resistance: but, the resistance of the air to swift motions being very great, the curve described by the shot is neither a parabola, nor near it: and by reason of the resistance, the angle which gives the greatest amplitude is not 45 degrees, as commonly supposed, but something less, probably 43¹⁄₂. Hence the sublime mathematics are absolutely necessary in the investigation of the track of a shell or shot in the air, known by the name of _military projectiles_.

Gallileo having discovered that bodies projected in vacuo, and in an oblique direction to the horizon, do always describe a parabola, he concluded that this doctrine was not sufficient to determine the real motion of a military projectile: for, since shells and shot move with a great velocity, the resistance of the air becomes so great with respect to the weight of the projectile, that its effect turns the body very considerably from the parabolic tract; so that all calculations, grounded on the nature of this curve, are of little use on these occasions. This is not to be wondered at, since Gallileo, in his enquiry, paid no regard to any other force acting on bodies, than the force of gravity only, without considering the resistance of the air.

Every body, moving in a fluid, suffers the action of two forces: the one is the force of gravity, or the weight of the body; and it is to be observed, that this weight is less than the natural weight of the body, that being diminished by an equal bulk of the fluid in which the body moves. The other force is that of the resistance, which is known to be proportional to the squares of the velocity of the body; and when the body is a globe, as is commonly supposed, the direction of this force is diametrically opposite to that of the motion of the body. This force changes continually, both in quantity and direction; but the first force remains constantly the same. Hence, the point in question is, to determine the curve which a body projected obliquely, must describe when acted upon by the two forces just now mentioned.

Although this question is easily reduced to a problem purely analytical, the great Newton, notwithstanding his ingenious endeavors, did not arrive at a complete solution of it. He was the first who attempted it, and having succeeded so well in the supposition, that the resistance is proportional to the velocity, it is almost inconceivable that he did not succeed, when the resistance is supposed proportional to the squares of the velocity, after solving a number of questions incomparably more difficult. The late Mr. John Bernoulli gave the first solution of this problem, from which he drew a construction of the curve, by means of the quadratures of some transcendent curves, whose description is not very difficult.

This great problem was, therefore, very well solved long ago; yet the solution, however good in theory, is such as has hitherto been of no use in practice, nor in correcting the false theory grounded on the parabola, to which the artillerist is still obliged to adhere, notwithstanding he knows it to be insufficient. It is certain, that that solution has been of no real advantage towards improving the art of gunnery: it has only served to convince the student in that art, of the error of his principles, drawn from the nature of the parabola, although he is still to abide by them. It is indeed something to know, that the common rules are erroneous; but unless we know how much they err in any case, the advantage is very little.

One may think it a work of infinite labor to establish rules for the flight of cannon shot, agreeable to the real curve which a body describes in the air: for although, according to the hypothesis of Gallileo, we want only the elevation of the piece, and the initial velocity, and it is therefore not difficult to calculate tables to show the greatest height of the projectile, and the point where it must fall in any proposed case; yet in order to calculate similar tables according to the true hypothesis, care must be taken, besides the two particulars already mentioned, to have respect as well to the diameter of the projectile as to its weight: therefore the practitioner will be reduced to the necessity of calculating tables, as well for the diameter of each projectile, as for its weight; and the execution of such a work would be almost impracticable. We therefore refer the curious to Mr. Euler’s _True Principles of Gunnery_, translated, with many necessary explanations and remarks, by the very learned and ingenious Hugh Brown.

PROJECTION, (_Projection_, _Fr._) in mathematics, the action of giving a projectile its motion. It is also used to signify a scheme, plan, or delineation.

PROJECT, (Projet, _Fr._) a term generally used among French engineers, to express what works are required to be made for the inward or outward defence of a fortified town or place. It likewise signifies, in diplomacy, a plan or statement of terms and conditions which one country makes to another for a final adjustment of differences.

_Contre_-PROJET, _Fr._ a receipt or answer to terms proposed, accompanied by a project from the other side.

PROLONGE, _Fr._ A long thick rope, which is used to drag artillery; but different from the bricole and drag rope; it is coiled round pins under the gun carriage travelling, it is loosed in action, and one end being attached to the limber, is of great use in moving the gun in action or in a retreat. See _Am. Mil. Lib._

PROMOTION, (_Promotion_, _Fr._) This word signifies, in military matters, the elevation of an individual to some appointment of greater rank and trust than the one he holds.

PROMOUVOIR, _Fr._ to promote.

PROMU, _Fr._ promoted.

PROOF, in arithmetic, an operation whereby the truth and justness of a calculation are examined and ascertained.

PROOF _of artillery and small arms_, is a trial whether they will stand the quantity of powder allotted for that purpose.

The British government allow 11 bullets of lead in the pound for the proof of musquets, and 29 in two pounds, for service; 17 in the pound for the proof of carabines, and 20 for service; 28 in the pound for the proof of pistols, and 34 for service.

When guns of a new metal, or of lighter construction, are proved, then besides the common proof, they are fired 2 or 300 times, as quick as they can be, loaded with the common charge given in actual service. British light 6 pounders were fired 300 times in three hours, 27 minutes, loaded with 1lb. 4oz. without receiving any damage.

PROOF _of ordnance_. All natures of ordnance undergo several kinds of proof before they are received into the British service; viz. 1st, they are guaged as to their several dimensions, internal and external, as to the justness of the position of the bore, the chamber, the vent, the trunnions, &c.

2d, They are fired with a regulated charge of powder and shot, and afterwards searched to discover irregularities or holes produced by the firing.

3d, By means of engines an endeavor is made to force water through them; and,

4th, They are examined internally, by means of light reflected from a mirror.

_Iron guns._ The guns are first examined as to their proper dimensions, in which, in no case more than ³⁄₁₀ of an inch variation is allowed; and in the diameter of the bore only ¹⁄₃₀ from 42 to 18 pounders, and ¹⁄₄₀ from 12 to 4 pounders; but in the position of the bore ¹⁄₂ an inch out of the axis of a piece from a 42 to an 18 pounder, and ¹⁄₃ of an inch from a 12 to a 4 pounder is allowed. They are then fired twice with the charge in the following table, with one shot and two high junk wads; and examined with a searcher after each round. In this examination they must not have any hole or cavity in the bore of ²⁄₁₀ of an inch in depth, behind the first reinforce ring, or ¹⁄₄ of an inch in depth before this ring.

+-------- Nature.| Proof |charge. -------+-------- Prs. |lbs. oz. 42 | 25 -- 32 | 21 8 24 | 18 -- 18 | 15 -- 12 | 12 -- 9 | 9 -- 6 | 6 -- 4 | 4 -- 3 | 3 -- 2 | 2 -- 1¹⁄₂| 1 8 1 | 1 --

Iron guns are scaled with ¹⁄₁₂ the weight of the shot.

_Brass guns._ From 1 pounders to 12 pounders the diameter of the bore must not vary more than ¹⁄₄₀ of an inch, and in no dimensions more than ²⁄₁₀. The following are the established charges for their proof. The heavy and medium guns with a charge equal to the weight of the shot, except the medium 12 pounder, which is proved with only 9lbs. The light guns with half the weight of the shot. The brass ordnance have not however been proved of late with such heavy charges, but with the following:

3 Prs. light, 3 times, with 1 lb. each round. 6 Prs. light, 3 times, with 2 lbs. each. 12 Prs. light, 2 times, with 4 lbs. each. 12 Prs. med., 2 times, with 5 lbs. each.

Any hole ·15 of an inch deep upwards or sideways in the bore, or ·1 in the bottom, between the breach and first reinforce; or ·2 of an inch upwards or sideways, or ·15 in the bottom of the bore, before the first reinforce ring, will be sufficient to condemn them.

_Brass Mortars and Howitzers._ The exterior dimensions are in no respect to deviate more than ¹⁄₁₀ of an inch in an 8 inch howitzer, and ¹⁄₂₀ in the Cohorn mortars and howitzers. Their bores and chambers not to deviate from their true diameters or positions more than ¹⁄₄₀ of an inch.

The brass mortars and howitzers are fired twice with their chambers full of powder, and an iron shell. The mortars on their own beds, at about 75 degrees elevation; and the howitzers on their carriages, at about 12 degrees. Iron mortars are proved on their iron beds, with a charge equal to the full chamber, and an iron shot equal in diameter to the shell.

Cohorn mortars, having a hole ·1 of an inch in depth in the chamber, or ·15 in the chase, are rejected: royal howitzers the same. 8 inch howitzers having a hole ·15 of an inch in depth in the chamber, or ·2 in the chase, will be rejected.

_Carronades._ The diameter and position of their bore and chamber must not deviate ¹⁄₂₀ of an inch. They are proved with two rounds, with their chambers full of powder and 1 shot and 1 wad. A hole of ²⁄₁₀ of an inch in depth in the bore, or ¹⁄₁₀ in the chamber condemns the piece.

_Proof Charges._

+--+--+--+--+-- 68 Prs.|42|32|24|18|12 -------+--+--+--+--+-- 13 lbs.| 9| 8| 6| 4| 3 -------+--+--+--+--+--

All ordnance, after having undergone this proof, and the subsequent searching, are subject to the water proof: this is done by means of a forcing pump, having a pipe or hose fixed to the mouth of the piece: after two or three efforts to force the water through any honeycombs or flaws which may be in the bore, they are left to dry; and generally the next day examined by the reflected light from a mirror. If the bore contains any small holes or flaws which have not been discovered by the former proofs, they are very readily found by this; the water will continue to weep, or run from the holes, when the solid parts of the bore are perfectly dry. Ordnance suspected of being bad are often subject to a more severe proof: that of firing 30 rounds quick, with the service charge and a shot; and in doubtful cases, where the purity of the metal is suspected, recourse has been had to chemical trials and analysis. A quantity of clean filings taken from a part of an iron gun free from rust, are dissolved in diluted sulphuric acid, and the quantity of gas disengaged during the solution accurately ascertained. The plumbago which remains after solution is also separated by filtration, and carefully weighed. Now it is well known that the purer the iron, the greater the quantity of inflammable gas obtained, and the less the proportion of plumbago which remains after the solution; from these two parts therefore a tolerable judgment may be formed of the quality of the metal. When the plumbago exceeds 4¹⁄₂ _per_ cent. the iron will always be found deficient in strength; and there has been no instance of a gun bursting where the plumbago did not exceed 3 _per_ cent.; that is, where 100 grains of the metal did not leave more than 3 grains of plumbago. The color of the plumbago is also to be attended to; when it is brown or reddish, it is an indication of hard metal, and when in quantities and mixed with coals, there can be no doubt but that the iron is too soft for cannon.

_Proof of Iron Shells._ After the shells are guaged and examined as to their dimensions and weight, they must be well scraped out, and the iron pin at the bottom of the inside must be driven down or broken off. They are then to be hammered all over, to knock off the scales, and discover flaws, and no hole, in the large shells is allowed, of more than ³⁄₄ of an inch deep. An empty fuze is then driven into the fuze hole, and the shell is suspended in a tub of water, in such manner that the shell be covered by the water, but that it does not run into the fuze: in this situation the nose of a pair of bellows is put in at the fuze hole, and several strong puffs given with the bellows; and if no bubbles rise in the water, the shell is concluded to be serviceable.

Ordnance condemned as unserviceable for any of the foregoing reasons, are marked as follows: ╳ D, or ╳ S, or ╳ W. The first signifies that they are found to be faulty in their dimensions, by Desagulier’s instrument; the second, by the searcher; and the third, by the water proof.

PROOF _of powder_, is in order to try its goodness and strength. There have been different inventions proposed and put in practice heretofore, for the proof of powder. See GUNPOWDER, and EPROUVETTE.

PROOF _of cannon_, is made to ascertain their being well cast, their having no cavities in their metal, and, in a word, their being fit to resist the effort of their charge of powder. In making this proof, the piece is laid upon the ground, supported only by a piece of wood in the middle, of about five or six inches thick, to raise the muzzle a little; and then the piece is fired against a solid butt of earth.

_Tools to_ PROVE _cannon are as follow_, viz. _Searcher_, an iron socket with branches, from four to eight in number, bending outward a little, with small points at their ends: to this socket is fixed a wooden handle, from eight to twelve feet long, and 1¹⁄₂ inch in diameter. This searcher is introduced into the gun after each firing, and turned gently round to discover the cavities within: if any are found, they are marked on the outside with chalk; and then the _searcher with one point_ is introduced, about which point a mixture of wax and tallow is put, to take the impression of the holes; and if any are found of ¹⁄₉th of an inch deep, or of any considerable length, the gun is rejected as unserviceable to government.

_Reliever_, an iron ring fixed to a handle, by means of a socket, so as to be at right angles: it serves to disengage the first searcher, when any of its points are retained in a hole, and cannot otherwise be got out. When guns are rejected by the proof masters, they order them to be marked ╳ which the contractors generally alter to _W P_, and after such alteration, dispose of them to foreign powers for Woolwich proof.

A most curious instrument for finding the principal defects in pieces of artillery, has been invented by lieutenant general Desaguliers, of the royal regiment of artillery. This instrument, grounded on the truest mechanical principles, is no sooner introduced into the hollow cylinder of the gun, than it discovers its defects, and more particularly that of the piece not being truly bored, which is a very important one, and to which most of the disasters happening to pieces of artillery, are in a great measure to be imputed; for, when a gun is not properly bored, the most expert artillerist will not be able to make a good shot.

PROOF _of mortars and howitzers_, is made to ascertain their being well cast, and of strength to resist the effort of their charge. For this purpose the mortar or howitzer is placed upon the ground, with some part of their trunnions or breech sunk below the surface, and resting on wooden billets, at an elevation of about 70 degrees.

The mirror is generally the only instrument to discover the defects in mortars and howitzers. In order to use it, the sun must shine; the breech must be placed towards the sun, and the glass over against the mouth of the piece: it illuminates the bore and chamber sufficiently to discover the flaws in it.

PROOF _armor_, armor hardened so as to resist the force of an arrow, a sword or other weapons in use before the discovery of gunpowder.

PROOF _charge_, the quantity of gunpowder which is used in trying the several pieces of ordnance.

PROPER, in military matters, stands as a reduplicative, serving to mark out a thing more expressly and formally, viz.

PROPER _front of a battalion_. The usual continuity of line which is given to the formation of a battalion, and which remains unaltered by the countermarch or wheelings of its divisions; or if altered is restored by the same operation.

PROPER _right_, the right of a battalion, company, or subdivision, when it is drawn up according to its natural formation.

PROPER _pivot_ flank in column, is that which, when wheeled up to, preserves the divisions of the line in the natural order, and to their proper front. The other may be called the _reverse_ flank. In column, divisions cover and dress to the proper pivot flank; to the left when the right is in front; and to the right when the left is in front.

PROPLASM. See MOULD.

PROPORTION, (_Proportion_, _Fr._) The relation which parts have among themselves, and to the whole.

PROPOSER _une personne pour une charge_, _Fr._ To recommend a person for a situation.

PROPOSITION, (_Proposition_, _Fr._) in geometry, the declaration of a truth which is proved by demonstration. Such are the propositions in Euclid’s Elements. Propositions are divided into _Problems_ and _Theorems_.

PROPREFECT, among the Romans, the prefect’s lieutenant, whom he commissioned to do any part of his duty in his place.

PROPRETE _des soldats_, _Fr._ Cleanliness required in soldiers. See SERJEANT.

PROPRETOR, the same in his relative capacity as proconsul among the Romans. He was a magistrate who, after having discharged the office of pretor at home, was sent into a province to act in the same capacity.

PROQUESTOR, among the Romans, the questor’s lieutenant, who discharged his office in his stead.

_To_ PROSECUTE, to carry on. Hence to prosecute the war.

PROSPECTIVE, appertaining to viewing.

PROSTYLE, any building having pillars in the front only.

PROTECTOR. This word sometimes denotes the regent of a kingdom. Oliver Cromwell assumed this title on the death of Charles I. of England; Bonaparte exercises the power of emperor over a great part of Germany, under the title of _Protector_ of the confederation of the Rhine.

PROTESTANT, an appellation first given in Germany to all who adhered to the doctrine published by Luther.

PROVEDITOR, (_Provediteur_, _Fr._) The Venetians had two appointments of this description before the revolution. One gave the supreme command of the armies on shore, the other that of the fleets.

Of these proveditors, there were three who had the direction of matters relating to policy throughout the signory.

PROVEDITOR-_general of the sea_, an officer in Italy, whose authority extended over the fleet, when the captain-general was absent. He had particularly the disposal of the cash.

PROVET, an artillery machine used with howitzers. See EPROUVETTE.

PROVISIONS, are properly those articles of food and sustenance which soldiers receive from the public, and which in the British service are payed for by deductions from their pay. There is taken a deduction of _six pence a day_ from the full pay of every Serjeant, corporal, trumpeter, drummer, fifer, private man of the life guards, horse guards, dragoon guards, dragoons, foot guards, infantry of the line, militia, fencible infantry, and companies of invalids, when serving out of Great Britain, on stations at which provisions are supplied by the public; also when embarked in transports, or other vessels; (except while serving as marines, or during their passage to and from India at the expence of the East-India company;) also when prisoners of war, and maintained at the expence of Great Britain; and likewise when in general hospitals, either at home or abroad. A deduction of _three pence halfpenny_ is likewise to be made from the full pay of each serjeant, &c. when stationed in Jamaica, in New South Wales, at Gibraltar, (the loss by exchange at the latter place continuing as before) and while on their passage to and from India at the expence of the East-India company.

These deductions commenced, in regard to the troops in Europe, on the 25th of February, 1799; and in regard to the troops abroad, on the 25th of April, 1799.

PROVISIONS. See RATION.

PROVISIONAL, (_Provisionel_, _Fr._) Temporarily established.

PROVISIONALLY, (_Provisoirement_, _Fr._) by way of provision, or temporary arrangement. This adverb is frequently used both in French and English to distinguish the exercise of temporary functions from that of permanent appointments.

PROVOST-_Marshal_, of an army, is an officer appointed to secure deserters, and all other criminals: he is often to go round the army, hinder the soldiers from pillaging, indict offenders, execute the sentence pronounced, and regulate the weights and measures used in the army when in the field. He is attended by a lieutenant’s guard, has a clerk, and an executioner.

PROWESS, valor, bravery in the field, military gallantry.

PSILOI, light armed men among the Greeks, who fought with arrows and darts, or stones and slings, but were unfit for close fight. They were in honor and dignity inferior to the heavy armed. Next to these were the peltasti, a middle sort of foot soldiers between the hoplitai and the psiloi, being armed with spears, but far inferior in bigness to those of the heavy armed; their name is taken from their narrow shields, called _Peltæ_. Potter’s Greek Antiquities, vol. II. chap. 3.

PUBLICANS, persons who keep alehouses, &c. for the accommodation of travelers. In England, troops upon the march, or in quarters, may be billeted on them.

PUCKA _fever_, _Ind._ a putrid fever. The bilious fever of tropical climates.

PUCKALLIES, _Ind._ leathern bags for carrying water. They are placed on the backs of oxen. The word is also used for water-carriers.

PUDLAYS, pieces of stuff to do the office of levers or hand spikes.

PUHUR _Din_, _Ind._ Watches kept in the day; of which there are four; a similar number is kept in the night, called _Puhurraat_.

PUISANT, _Fr._ a well built of dry stones, or made in a wall to serve as a reservoir for water.

PUISSANCE, _Fr._ in algebra and geometry, powers of lines and quantities.

PUISOIR, _Fr._ a copper vessel which is used in making saltpetre.

PUITS, _Fr._ A well.

PUITS _de mineur_, _Fr._ a perpendicular opening, about four feet square, which is made in the earth for miners to let themselves down, as deep as may be judged expedient, in order to push the subterraneous galleries beneath the covert way, or under any other works constructed by the besieged or besieger.