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time a modification is made which contains gun-cotton 65%, nitro-glycerin 30 %, and mineral jelly 5 %. This is known as Cordite M.D. The advantages of Cordite M.D. over Mark I are slightly reduced See also:

RATE

rate of burning, higher velocities and more See also:

REGULAR

regular pressure in the gun, and See also:

LOWER

lower temperature. Cordite of either mark is a perfectly waterproof substance, containing only traces of See also:

WATER

water remaining from the manufacturing processes. It has a See also:

DENSITY (Lat. densus, thick)

density of about 1.56 at the See also:

ORDINARY (med. Lat. ordinarius, Fr. ordinaire)

ordinary temperature (15° C.), and, as its coefficient of expansion is small, this density does not See also:

CHANGE (derived through the Fr. from the Late Lat. cambium, cambiare, to barter; the ultimate derivation is probably from the root which appears in the Gr. «a urmu', to bend)

change to any serious extent under See also:

CLIMATIC

climatic temperature See also:

variations. A See also:

rod may be See also:

bent to a moderate extent without breaking, and Cordite M.D. especially shows considerable See also:

ELASTICITY

elasticity.

It can be impressed by the See also:

NAIL (O. Eng. naegal, cf. Dutch, Ger., Swed. nagel; the word is also related to Lat. unguis, Gr. ovu, Sans. nakhas)

nail and cut with a See also:

KNIFE (0. E. cuff, a word appearing in different forms in many Teutonic languages, cf. Du. knijf, Ger. Kneif, a shoe-maker's knife, Swed. knif; the ultimate origin is unknown; Skeat finds the origin in the root of " nip," formerly " knip "; Fr. canif is a

knife, but is not in the least sticky, nor does the nitro-glycerin exude to any appreciable extent. It can be obtained in a finely-divided state by scraping with a See also:

sharp knife, or on a new See also:

FILE

file, or by grinding in a See also:

mill, such as a See also:

COFFEE (Fr: cafe, Ger. Kaffee)

coffee-mill, but can scarcely be pounded in a See also:

MORTAR

mortar. Cordite is of a brownish See also:

COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour in See also:

mass, but is much paler when finely ground or scraped. The rods easily become electrified by See also:

GENTLE (through the Fr. gentil, from Lat. gentilis, belonging to the same gens, or family)

gentle See also:

FRICTION (from Lat. fricare, to rub)

friction with a dry substance. Like all colloidal substances it is an exceedingly See also:

BAD, BCD

bad conductor of See also:

HEAT (0. E. haktu, which like " hot," Old Eng. hat, is from the Teutonic type haita, hit, to be hot; cf. Ger. hitze, heiss; Dutch, hitte, heet, &c.)

heat. A piece ignited in See also:

air See also:

burns with a yellowish See also:

FLAME (Lat. flamma; the root flag- appears in flagrare, to burn, blaze, and Gr. d, XEryew)

flame. With the smaller sizes, about 2 mm. diameter or less, this flame may be blown out, and the rod will continue to See also:

BURN, RICHARD (1709-1785)

burn in a suppressed manner without actual flame, fumes containing oxides of See also:

NITROGEN [symbol N., atomic weight 14.01, 0=16]

nitrogen being emitted. Temperature appears to have an effect on the rate of burning. When much cooled it certainly burns more slowly than when at the ordinary air temperature, and is also more difficult to ignite. Rods of moderate thickness, say from 5 mm. diameter, will continue to burn under water if first ignited in air and the burning portion slowly immersed. The end of a rod of cordite may be struck a moderately heavy See also:

BLOW, JOHN (1648-1708)

blow on an See also:

ANVIL (from Anglo-Saxon anfilt or onfilti, either that on which something is " welded " or " folded," cf. German falzen, to fold, or connected with other Teutonic forms of the word, cf. German amboss, in which case the final syllable is from " beat," and

anvil without exploding or igniting. The rod will first flatten out.

A sharp blow will then detonate or explode the portion immediately under the See also:

HAMMER, FRIEDRICH JULIUS (1810-1862)

hammer; the See also:

REMAINDER, REVERSION

remainder of the rod remaining quite intact. Bullets may be fired through a bundle or package of cordite without detonating or inflaming it. This is' of course a valuable quality. The exact temperature at which substances ignite or take See also:

FIRE (in O. Eng. f j'r; the word is common to West German languages, cf. Dutch vuur, Ger. Feuer; the pre-Teutonic form is seen in Sanskrit pu, pavaka, and Gr. irup; the ultimate origin is usually taken to be a root meaning to purify, cf. Lat. purus)

fire is in all cases difficult to determine with any exactness. Cordite is not instantly ignited on contact with a flame such as that of a See also:

CANDLE (Lat. candela, from candere, to glow)

candle, because, perhaps, of the condensation of some moisture from the products of burning of the candle upon it. A blow-See also:

PIPE

pipe flame or a red-hot See also:

WIRE (A.S. wir, a wire; cf. Swed. vire, to twist, M.H.G. wiere, a gold ornament, Lat. viriae, armlets, ultimately from the root wi, to twist, bind)

wire is more rapid in See also:

ACTION

action. The ignition temperature may be somewhere in the region of 18o° C. All the members of this class of explosive when kept for some time at (for them) moderately high temperatures, such as the boiling-point of water (roo° C.), show signs of decomposition; oxides of nitrogen are liberated, and some complex oxidation processes are started. Carefully prepared gun-cotton and nitro-glycerin will, however, withstand this temperature for a See also:

long time without serious detriment, excepting that nitro-glycerin is slightly volatilized. When incorporated in cordite, however, the nitro-glycerin appears to be much less volatile than when See also:

FREE

free at this temperature. Under reduced pressure (3 or 4 in. only of See also:

mercury instead of 3o) it is possible to distil away a considerable amount of nitro-glycerin from cordite at too° C. It is very doubtful whether at ordinary temperatures and pressures any nitro-glycerin whatever evaporates.

Cordite may be kept in contact with clean, dry metals, See also:

wood, See also:

paper, and a number of ordinary substances without deterioration. In contact with See also:

DAMP

damp and easily oxidizable metals all the substances of the gun-cotton class are liable to a slight See also:

LOCAL

local action, but the colloid nature, and probably also the contained mineral jelly, protect cordite considerably in these circumstances. See also:

AMMONIA (NH3)

Ammonia has a deleterious action, but even this proceeds but slowly. Cordite does not appear to change when kept under water. The manufacturing processes comprise: drying the gun-cotton and nitro-glycerin; melting and filtering the mineral jelly; weighing and mixing the nitro-glycerin with the gun-cotton; moistening this mixture with See also:

ACETONE, or DIMETHYL KETONE

acetone until it becomes a jelly; and then incorporating in a See also:

SPECIAL

special mixing mill for about three See also:

HOURS, CANONICAL

hours, after which the weighed amount of mineral jelly is added and the See also:

INCORPORATION (from Lat. incorporare, to form into a body)

incorporation continued for about one See also:

HOUR

hour or until judged See also:

COMPLETE

complete. The incorporating or mixing See also:

machine is covered as closely as possible to prevent too See also:

GREAT

great evaporation of the very volatile acetone. Before complete incorporation the mixture is termed, in the See also:

WORKS

works, " See also:

PASTE (O. Fr. paste, modern pate, Late Lat. pasta, whence also in Span., Port. and Ital., from Gr. 1r&vrrl or 1raara, barley porridge, or salted pottage, ir&ao'ety, to sprinkle with salt)

paste," and, when finally mixed," dough." The right consistency having been produced, the material is placed in a steel See also:

CYLINDER (Gr. KvAwSpos, from KvXivaety, to roll)

cylinder provided with an arrangement of dies or holes of regulated size at one end, and a See also:

PISTON (through Fr. from Ital. pistone or pestone, a great pestle, from Late Lat. pistare, to pound, a frequentative form of classical Lat. pinsere)

piston or plunger at the other. The plunger is worked either by hydraulic See also:

POWER [WILLIAM GRATTAN] TYRONE (1797-1841)

power or by a screw (driven from ordinary shafting). Before reaching and passing through the holes in the See also:

die, the material is filtered through a disk of See also:

FINE

fine wire See also:

GAUZE

gauze to retain any See also:

FOREIGN

foreign substances, such as See also:

sand, bits of wood or See also:

metal, or unchanged See also:

fibres of See also:

CELLULOSE

cellulose, &c., which might choke the dies or be otherwise dangerous. The material issues from the cylinders in the form of See also:

CORD (derived through the Fr. corde, from the Lat. chorda, Gr. xop(5rt, the string of a musical instrument)

cord or See also:

STRING

string of the diameter of the holes of the die. The thicker sizes are cut off, as they issue, into lengths (of about 3 ft.); it being generally arranged that a certain number of these—say ten—should have, within narrow limits, a definite See also:

WEIGHT

weight. The small sizes, such as those employed for See also:

RIFLE

rifle cartridges, are See also:

WOUND (O. Eng. wund,connected with a Teutonic verb, meaning to strive, fight, suffer, seen in O. Eng. winnan, whence Eng. " win ")

wound on reels or drums, as the material issues from the See also:

PRESS (through Fr. presse from Lat. pressare, frequentative of premere, to crush, squeeze, press)

press cylinders, in lengths of many yards.

Some of the solvent or gelatinizing material (acetone) is lost during the incorporating, and more during the pressing See also:

PROCESS

process and the necessary handling, but much still remains in the cordite at this See also:

STAGE (Fr. 6/age; from Lat. stare, to stand)

stage. It is now dried in heated rooms, where it is generally spread out on shelves, a current of air passing through carrying the acetone vapour with it. In the more See also:

MODERN

modern works this air current is See also:

DRAWN

drawn, finally, through a See also:

SOLUTION (from Lat. solvere, to loosen, dissolve)

solution of a substance such as See also:

SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium bisulphite a fixed See also:

compound is thus formed with the acetone, which by suitable treatmentmay be recovered. The time taken in the drying. varies with the thickness of the cordite from a few days to several See also:

WEEKS, EDWIN LORD (1849-1903)

weeks. For several reasons it is desirable that this process should go on gradually and slowly. After drying, all the various batches of cordite of the sanie size are carefully " blended, " so that any slight See also:

DIFFERENCES, CALCULUS OF (Theory of Finite Differences)

differences in the manufacture of one batch or one See also:

day's output may be equalized as much as possible. Slight differences may arise from the raw materials, cotton See also:

WASTE (O. Fr. wast, guast, gast, gaste; Lat. vastus, vast, desolate)

waste or glycerin, or in the making of these into gun-cotton or nitro-glycerin respectively. To help in See also:

con-trolling the blending, each " make" of gun-cotton and nitro-glycerin is ." marked " or numbered, and carries its mark to the cordite batch of which it is an ingredient. The See also:

HISTORY

history of each See also:

box of large-sized or See also:

REEL (O.E. hreol, glossed by the Med. Lat. alibrum in .lelfric's Glossary, c. 1o5o; the word is of unknown origin; it does not appear in cognate languages, and Celtic forms such as Gaelic ruidhil are from English)

reel of small-sized cordite is therefore known up to the operation of blending and packing. The final testing. is by firing proofs, as in the See also:

case of the old gunpowders. The gun-cotton employed for cordite is made in the usual way (see GUN-COTTON), with the exception of treating with See also:

ALKALI

alkali. It is also after complete washing with water gently pressed into small cylinders (about 3 in. diameter and 4 in. high) whilst wet, and these are carefully dried before the nitro-glycerin is added.

The pressure applied is only sufficient to make the gun-cotton just hold together so that it is easily mixed with the nitro-glycerin. The mineral jelly or See also:

VASELINE

vaseline is obtained at a certain stage of See also:

DISTILLATION (from the Lat. distillare, more correctly destillare, to drop or trickle down)

distillation of See also:

PETROLEUM (Lat. Petra, rock, and oleuin, oil)

petroleum, and is a mixture of See also:

HYDROCARBONS

hydrocarbons; paraffins, olefines and some other unsaturated hydrocarbons,, possibly aromatic, which no doubt See also:

PLAY

play a very important See also:

PART

part as preservatives in cordite. The stability of cordite, that is, its capability of keeping without chemical or ballistic changes, is judged of by certain " heat tests. The Abel heat test consists in subjecting a weighed quantity, 2 grams, of the finely divided cordite contained in a test See also:

TUBE (Lat. tuba)

tube, to a temperature of 7o° C. maintained See also:

CONSTANT, BENJAMIN (1845-1902)

constant by a water See also:

bath. The test tube is about 6X4 in., and dips into the water sufficiently to immerse about 2 in., viz. the part containing the cordite. In the upper free portion a piece of See also:

FILTER (a word common in various forms to most European languages, adapted from the medieval Lat. fi-ltrum, felt, a material used as a filtering agent)

filter-paper impregnated with a mixture of See also:

POTASSIUM [symbol K (from kalium), atomic weight 39.114 0=16)]

potassium iodide and See also:

STARCH

starch paste is suspended by a See also:

PLATINUM [symbol Pt, atomic weight 145.0 (0=16)]

platinum wire from the stopper of the tube. A portion of the test paper is moistened with a solution of glycerin to render it more sensitive than the dry part. A faint See also:

brown colour appearing on the moistened portion indicates that some oxides of nitrogen have been evolved from the cordite. This brown tint is compared with a See also:

standard, and the time taken before the standard tint appears is noted. The time fixed upon as a test of relative stability is an arbitrary one determined by examination of well-known specimens. Should the cordite or other explosive contain traces of mercury salts, such as mercuric chloride, which is sometimes added as a preservative, this test is rendered nugatory, and no coloration may appear (or only after a long exposure), although the See also:

SAMPLE (through the O. Fr. essemple, from Lat. exemplum; a doublet of " example ")

sample may be of indifferent stability. It is now customary to examine specially for mercury, either by See also:

HEATING

heating the explosive in contact with See also:

gold See also:

LEAF (O. Eng. leaf, cf. Dutch loof, Ger. Laub, Swed. lof, &c.; possibly to be referred to the root seen in Gr. Ma-eta, to peel, strip)

leaf or See also:

SILVER

silver See also:

FOIL

foil, or by burning the substance and examining the flame in the spectroscope.

The method of examination known as the vacuum silvered See also:

VESSEL (O. Fr. vaissel, from a rare Lat. vascellum, dim. of vas, vase, urn)

vessel process is probably not interfered with by the presence of very small quantities of mercury. It consists in heating 5o. grams of the finely divided explosive in a See also:

DEWAR, SIR JAMES (1842- )

Dewar's silvered vacuum See also:

glass bulb to a rigidly constant temperature of 8o C. for many hours. A sensitive thermometer having its bulb immersed in the centre of the cordite shows when the temperature rises above 8o°. Such a rise indicates See also:

INTERNAL

internal oxidation or decomposition of the explosive; it is accompanied by an See also:

EVOLUTION

evolution of nitrogen dioxide, NO2, the See also:

DEPTH

depth of colour of which is noted through a See also:

side tube attached to the bulb. As all See also:

EXPLOSIVES

explosives of this class would in time decompose sufficiently to give these indications, time periods or limits have been fixed at which an appreciable and definite rise in temperature and See also:

PRODUCTION (Lat. productionem, from producere, to pro-duce)

production of red fumes indicate relative stability or instability. (W. R. E.

End of Article: CORDITE

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