PICKET. A small out-post guard.

PIONEERS. Bodies of soldiery provided with suitable imple. ments, who go in advance to clear the way.

PLATOON. One half a company. The two platoons are called respectively first and second platoons.

POINT BLANK. The point of distance at which, when a cannon or fire-arm is aimed, the axis of the piece is on a line with it. PONTOONS. Boats, or inflated india-rubber bags, upon which planks are placed to form a bridge.

PORT-FIRE. A cylindrical case of paper, filled with a combus tible material, and used sometimes in firing cannon.

QUARTERMASTER. The officer whose duty it is to provide the soldiers with quarters and clothing. The Quartermaster's department of the United States embraces officers of all grades, from the colonel commanding to captains.

RALLY. To re-form disordered troops; to bring skirmishers into close order; to collect retreating troops for a new attack. RAMPART. A broad embankment surrounding a fortified place. It includes the parapet and other raised works.

RANK. The range or order of seniority in commission.

RANK AND FILE. The corporals and privates of an army, or those who parade in the ranks habitually. Lineal rank is the order of promotion by seniority. Brevet rank is honorary rank conferred for meritorious service.

RATIONS. The daily allowance of meat, bread, and other provisions to a soldier.

RECONNOISSANCE. The survey and examination of a portion of country, or any point, with a view to military movements. RECRUIT. Literally, a soldier enlisted to take a vacant place in a company; commonly, any new soldier.

REDAN. A portion of fortification included in a single salient angle.

REDOUBT. Any small, isolated fort. It is usually defensible on all sides.

REGIMENT. A body of troops comprising ten companies, and commanded by a colonel.

REGULATIONS. A system of orders and instructions on all subjects connected with the management of the army. They are published together, and constitute "The Army Regulations."

RELIEF. A division of the guard-usually one third. These are called first, second, and third relief. The sentinels of each relief are on post for two hours, and off for four.

RESERVE. A select body of troops held back for a decisive moment. In light infantry, the compact nucleus upon which the skirmishers rally.

RETREAT. The parade at sunset, when the evening gun is fired, and the flag taken down for the night.

REVEILLE. The early morning drum-beat and roll-call, usually accompanied by the morning gun.

REVETMENT. Any wall or strengthening process of the earthworks of a fort. Sometimes a work is revetted with sand bags or fascines. Permanent forts are revetted with masonry.

RICOCHET. The rebounding of a shot, usually propelled by a small charge, and with the gun pointed at an elevation of less than ten degrees. By striking in more spots than one, it does greater damage.

RIFLE. Any fire-arm which has a curved groove running

down its length from the muzzle to the bottom of the bore. Cannon are rendered more effective by rifling.

ROLL-CALLS. Stated daily parades of the company, with or without arms, for calling the roll and seeing that every man is in his place.

ROSTER. A list of officers and men, from which details for guard and other duties are made, -on the principle that the longest off any duty shall be detailed for the next tour.

SABRETASCHE (German- Sabel, sabre, and Tasche, pocket). A leathern case, suspended at the left side of a mounted officer, in which papers are carried.

SAFEGUARD. A passport given by competent authority to a person passing through military lines. It is usually both for persons and property.

SALIENT. Any advanced point or angle in fortification.

SALLY-PORT. The chief entrance to a fort, to afford egress to bodies of troops, as in a sortie.

SALUTE. A discharge of artillery or musketry in honor of persons of rank. The rank is denoted by the number of guns fired.

SAND BAGS. Coarse bags filled with sand, for revetting earthworks and repairing breaches made in them by shot.

SAP. A ditch constructed rapidly by the besiegers in advancing upon a besieged place. According to the dimensions, it is called a full sap, a flying sap, or a double sap. Those who make them are called sappers.

SENTINEL. An individual of the guard who is posted to watch for the safety of the camp, and who paces on his post, always alert, and who holds no communication with any person unauthorized to approach him.

SERGEANT. The highest grade of non-commissioned officer. Besides the sergeants who form part of the company organization, in each regiment there is a sergeant-major, who assists the adjutant; a quartermaster-sergeant, who assists the quartermaster; and a color sergeant, who carries the colors; and, at military posts, an ordnance-sergeant, who has charge of the ammunition.

SHELLS. Hollow balls, filled with combustible matter, which is fired by a fuse. They are shot from guns and mortars, and explode when they reach the object aimed at.

SIEGE. The act of surrounding a fort or place with an army, with a view to reducing it by regular approaches.

SKIRMISH. A loose, desultory kind of engagement, generally between light troops thrown forward to test the strength and position of the enemy.

SORTIE. A secret movement, made by a strong detachment of troops in a besieged place, to destroy or retard the enemy's approaches.

STAFF. The officers connected with head-quarters.

STOCKADE. A line of stakes or posts fixed in the ground as a barrier to the advance of the enemy.

SPHERICAL CASE. A thin shell filled with musket balls and powder.

SPIKE. To close the vent of a gun with a nail forcibly driven in. SHOT. The following are among the different kinds of shot: round, bar, canister or case, grape, and red-hot shot.

SECTIONS. Subdivisions of platoons.

TATTOO. The drum-beat just preceding the retirement of troops, usually at half-past nine o'clock.

TIME. The regular cadence in marching. Common time is ninety steps to the minute; quick time, one hundred and ten; double quick, one hundred and sixty-five.

TRAVERSES. Masses of earth thrown up at short distances in forts along the line of the work, to screen the troops from shot and shells fired in ricochet.

TERRE-PLAIN. The level terrace of a parapet on which the cannon are placed.

TETE-DU-PONT. Works thrown up at one end of a bridge to cover the communication across a river.

TRENCHES. The parallels dug by the besiegers in approaching a work.

TROOP. A company of cavalry.

TROUS DE LOUP. Conical holes dug in the earth, about six feet deep, and four and a half wide at the top. A sharp stake is fastened at the bottom, and the whole slightly covered, so as to conceal them from the enemy. Rows of trous de loup are very destructive to cavalry. (The name is French, and means wolfholes.)

TRUNNION. A pivot projecting from the side of a piece of ordnance, by which it rests on the cheek of the carriage.

TUMBRELS. Covered carts used to convey tools, &c. VANGUARD. The body of troops constituting a guard, detailed, from day to day, to march in advance of the army.

VIDETTE. Originally, sentinels on the farthest outposts. Now confined to mounted sentinels on outpost duty.

VOLLEY. The simultaneous discharge of a number of cannon, or muskets, or any fire-arms.

WINGS. The portion of an army on the right and left.

ZOUAVES. Light infantry troops, having a peculiar dress and drill, and trained to exercise quick and unusual movements with great rapidity and precision.

SIGNALS AND TELEGRAPHS,

INVENTED BY MAJOR MYERS.

Small flags by day and rockets and watch fires by night are the principal signals used by the Signal and Telegraph corps, and they are the occasion of many picturesque scenes.

Each army in the field has its corps in readiness with large coils of wire, portable apparatus, and every convenience. There are even reels, like hose carriages, on which is wound wire cased in cord, for communication with the aeronauts when these observers of the enemy's movements make their ascensions. One end of the wire is fixed to an apparatus taken up in the basket of the balloon, (which is held by a strong rope,) while the other end acts as an apparatus on the reel. An officer on the ground can thus direct the observations of those above him, and Tearn what they can see,

THE IRON-PLATED STEAM BATTERIES.

A proposition is now before Congress for the construction of twenty armor-clad gunboats, for which plans and specifications have been prepared by the Navy Department. The following description of these proposed vessels is from the New York Post:

The length of the vessel on deck is to be two hundred and sixteen feet two inches; extreme breadth forty-eight feet; and depth of hold amidships thirteen feet eleven inches. The hull is to be built throughout of white oak, and copper-fastened to within five feet of the top of the deck. The deck planks are to be white oak, five and one half inches thick and nine inches wide. On this deck there will be deck lights, fitted with shutters to make them water-tight from below, and two conning houses, (for guiding the ship,) one at each end, which are to be of wrought iron plates, round in form, of two feet diameter in width, and forty-six inches high, the sides to be six inches thick, composed of one thickness of four-inch and one of two-inch iron. The lid of the box is to be four inches thick. At ten inches below the bottom of th cover the sides are to be pierced with four tapering peep-hole", two inches in diameter on the outside and six inches on the iside; while three inches lower down there will be, fa intermediate spaces, four other peep-holes.

The armament of the vessel is to be contained in two revolving "Cole-towers," whose outside diameter is to be twenty-one and one half feet, and height somewhat over eight feet. The towe s are to be composed of two thicknesses of wrought iron plat s, securely bolted to a backing of oak ten inches thick, on vertical timbers. The outside plates to be three inches, and the ins de two inches thick, and all plates and appendages to be of first quality wrought iron scrap, capable of sustaining a t r.sile strin of fifty-five thousand pounds per square inch.

Each tower will have one port-hole cut in its side for a gun; this hole to be twenty-four inches wide and forty-one inches extreme height, top and bottom to be semicircular. In the roof is to be a grating, composed of slabs of wrought iron six inches deep and one inch wide. Each tower rests on twelve wrought iron conical rollers, eighteen inches diameter, sever ir.ches width of face, turned and polished, and with steel axles, o work in a wrought iron circular railway secured to the deck it every eighteen inches of its circumference.

On the outside of the tower, the base, to the heat of twentysix inches above the deck, is to be a glacis, or inclined plane, extending ten feet in every direction from the circumference of the tower itself, and composed of two plates, each one and a quarter inches thick, fastened on proper timbers. This glacis will protect the railway on which the tower revolves, with its machinery. The sides of the vessel are to be plated with four and a quarter inch wrought iron plates, except for thirty feet from the stern and stern posts, where the plates are but three and three quarters, and nearer the bow three and a quarter inches thick. The deck Is to be covered with ten thicknesses of rolled iron plates, each three quarters of an inch thick, and not less than fifteen feet long, and three feet wide.

The entire weight of iron plates needed for one of these vessels is thus estimated in the specifications:

The motive power is to consist of two horizontal direct acting engines, to work two screw propellers, one under each counter of the vessel. The screw propellers are to be four-bladed, of ten feet diameter, with a mean pitch of twelve feet six inches.

The gun towers will each be worked by an oscillating engine. For ventilating the berth deck there are, besides these, to be four blowing engines and blowers.

STEEL-CLAD SHIPS.

QUALITIES OF STEEL-CLAD SHIPS.

Every one has read, for the last few years, of the progress of experiments in steel-plated men-of-war, and we have had detailed accounts of English and French ships, and elaborate discussions on their comparative merits. The testimony seems to be conclusive that this plating is to change the character of all navies; in fact, that a navy of wooden ships is no longer a navy worth having, if they are to be opposed to steel-clad ships. It seems to be a settled thing that steel plates of four and one-half inches in thickness, and properly backed, will withstand the 100-pounder Armstrong gun at point-blank range. The vessels, plated on their sides, are generally protected on decks by a covering, which is intended to shed any shot which may strike. Besides these desirable qualities, the ships have protection for riflemen. In the great Stevens battery the men serving the guns are to accomplish their duty by the aid of mechanism, which allows them to remain in a place of perfect security. Assuming all this to be true, and we believe it to be true, it follows that, unless guns can be so improved as to advance in capability of destructiveness in proportion as material is combined to resist their power, all firing at a ship provided with the most approved armor would be a mere waste of ammunition. A ship so protected, and armed, as intended, with the heaviest cannon, is not only a fortification, but it is a line of forts; it is more-it is a perfect line of circumvallation. If such a ship, in action, should progress two miles, it would be equal, if not to a fortification of that length, at any rate it would be equal to a fortification not much less, and might be equal to much more, from capability of locomotion. Such a ship could destroy any number of wooden ships which might be opposed.

ENGAGEMENT BETWEEN TWO STEEL-CLAD SHIPS.

Another reflection is suggested by the adoption of armor for ships. How is a steel-plated ship to engage a steel-plated ship? Their guns can do no execution on each other, and sailors,