Part 185

GRATIFICATION likewise means a certain allowance in money which is made to prisoners of war. The British officers in France have been allowed 6d. per day, and the non-commissioned and soldiers 1¹⁄₂d. the officers have also 1s. 6d. in lieu of rations.

GRATTER un Vaisseau, Fr. to clean or careen a ship.

GRATTER en maconnerie, Fr. to restore the original appearance of a wall or building by grating the superficies with a trowel, or any other iron instrument.

GRAVEURS, Fr. Persons employed and paid by the founders of cannon for repairing damaged pieces of artillery. Some individual, however, was distinguished by the name of Graveur de l’Artillerie, Engraver to the Artillery, and was permitted, by the Grand Master of the Ordnance, to exhibit over his shop-door the arms of the royal artillery.

GRAVITY.--Table of the Specific gravity of several Solid and Fluid bodies.

Platina 23400 Fine gold 19640 Standard gold 18888 Quick silver 11325 Fine silver 11091 Standard silver 10535 Copper 9000 Copper halfpence 8915 Gun metal 8784 Cast brass 8000 Steel 7850 Iron 7645 Cast iron 7425 Tin 7320 Crystal glass 3150 Marble 2700 Common green glass 2600 Flint 2570 Common stone 2520 Clay 2160 Brick 2000 Common earth 1984 Nitre 1900 Ivory 1825 Brimstone 1810 Solid gunpowder 1745 Sand 1520 Coal 1250 Boxwood 1030 Sea water 1030 Common water 1000 Oak 925 Gunpowder, close stacken 937 Do. in loose heap 836 Ash 800 Maple 755 Elm 600 Fir 550 Charcoal Cork 240 Air 1.232

The several sorts of wood are supposed dry.

This table also contains the weight of a cubic foot of each body in avoirdupois ounces; from whence results the following rules:

1. To find the magnitude of any body from its Weight.

As the tabular specific gravity of the body,

Is to its weight in avoirdupois ounces.

So is one cubic foot, or 1728 cubic inches,

To its contents in feet or inches respectively.

2. To find the weight of a body from its magnitude.

As one cubic foot, or 1728 cubic inches,

Is to the content of the body,

So is the tabular specific gravity

To the weight of the body.

GRAVOIS, Fr. rubbish.

GREAT fortification. One of the divisions of the first system of M. de Vauban.--It consists in a fortification whose exterior side is from 185 to 260 toises, or from 370 to 520 yards, and is seldom adopted but towards a river or a marsh.

GREAT radius. The whole oblique radius. See FORTIFICATION.

GRECIAN fire, feu Gregeois, Fr. a sort of artificial fire, which insinuates itself beyond the surface of the sea, and which burns with increased violence when it mixes with that element. Its directions are contrary to the course of natural fire; for the flames will spread themselves downwards, to the right or left, agreeably to the movement that is given. It is composed or made up of naphtha, sulphur, bitumen, gum and pitch; and it can only be extinguished by vinegar mixed with urine and sand, or with undressed leather or green hides. Some writers assert, that it was invented by an engineer (belonging to Heliopolis, a town in Syria,) whose name was Gallinicus, and who used it with so much skill and effect during a naval engagement, that he destroyed a whole fleet belonging to the enemy, upon which were embarked 30,000 men. This combustible matter has retained the name of Grecian fire, because the Greeks first practised the invention. It is asserted indeed, that the secret of making Grecian fire, which should be unextinguishable, has been long since lost; we say unextinguishable, because the ancients did nor know, as we do, how to repress or put out the flame.

According to the author of Oeuvres Militaires, a powerful composition, which could only be extinguished by strong vinegar (a secret unknown to the ancients) might be made of the following combustible materials: viz. pitch, rosin, tallow, camphor, turpentine, salt of nitre, liquid varnish, oil of sulphur, linseed, rock oil, flax, charcoal finely pulverized; the whole of which being boiled together, and before it grows cold, mixed with quick lime: a consistence is formed that will be susceptible of the most subtle and destructive fire.

GRENADES, GRANADES or GRENADOES, in the art of war, are hollow balls or shells of iron or other metal, about 2¹⁄₂ inches diameter, which being filled with fine powder, are set on fire by means of a small fuse, driven into the fuse-hole, made of well seasoned beech wood, and formerly thrown by the grenadiers into places where men stood thick, and particularly into the trenches and other lodgments made by the enemy. As soon as the composition within the fuse gets to the powder in the grenade, it bursts into many pieces, greatly to the injury of all who happen to be in its way. Grenades were first made about the time shells were invented (which see) and first used in 1594. Grenades have much sunk into disuse; but nothing is more effectual than grenades thrown into the midst of the enemy, who have jumped into the ditch. During the siege of Cassel, under the Count de Lippe, in the campaign of 1762, a young engineer undertook to carry one of the outworks, with a much smaller detachment than had before attempted it without success. He gained his object with ease, from the use of grenades; which is a proof that they should not be neglected, either in the attack or defence of posts.

GRENADE, grenade, Fr. There is a sort of grenade which is thrown out of a mortar.

It is sometimes used for the purpose of annoying the besieging enemy; in which case quantities are rolled down the rampart into the fossé, or ditch, upon the workmen or miners.

A grenade resembles a bomb or shell, with this only difference, that the grenade has not any handles to it.

There are some grenades, called grenades à main hand-grenades, whose calibre is equal to that of a four pounder. The charge is from five to six ounces of gunpowder, or thereabouts. They are extremely serviceable on many occasions: but particularly so to throw among the men that are working in the trenches; numbers of whom they must inevitably wound. The vent of a hand-grenade contains about six lines, or half an inch.