Page:Encyclopædia Britannica, Ninth Edition, v. 11.djvu/292

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278
GUN—GUN

of action of gun-cotton by Yon Lenk s researches. By the system which Abel has more recently elaborated the fibre after its conversion into gun-cotton is reduced to a very fine state of division ; when in this condition the explosive substance is readily converted into sheets or granules, or by compression into homogeneous masses of various degrees of compactness, and of any desired form. In this manner the rapidity of action or explosion of gun-cotton may be reduced to a minimum, though uniformity of action in fire arms is still very difficult to attain with it. As the reduction of the gun-cotton fibre to a very fine state of division greatly facilitates the removal by washing, and by alkaline treatment, of the small quantities of unstable impurities already spoken of, the stability of gun-cotton as now manufactured is much greater than that of former products. Compressed gun-cotton needs, like the other forms in which this explosive has been used, very strong confinement for the development of violent explosion, but this can be readily accomplished without any confinement of the substance, through the agency of an initiative detonation; the explosion of 2 grains of strongly confined mercuric fulminate in close contact ivith the compressed material suffices to ensure this result (see Detonation, article Explosives, vol. viii. p. 809). Gun-cotton contains in the normal (air dry) condition 2 per cent. of water. The compressed material of the ordinary density ( = about 1) contains from 25 to 30 per cent, of water when saturated; even with 15 per cent, it is uninflammable, and when containing 17-20 per cent, it may be cut and drilled with perfect safety. If gun-cotton contains more than the normal 2 per cent, of water it can no longer be detonated by the minimum quantity of fulminate, and the strength of the initiative detonation has to be increased in proportion to the amount of water it contains ; when it contains 17 per cent, of water, its detonation cannot be accomplished with less than 200 grains of confined fulminate. An initiative charge of 1 ounce of air dry gun-cotton (detonated by means of an ordinary fulminate fuze) suffices, however, to ensure the detonation of wet gun-cotton (as used in mines, torpedoes, rockets, &c.). The susceptibility of gun-cotton to detonation when wet (and therefore perfectly uninflammable) gives this substance a great advantage over other explosive agents, as it may be stored in a perfectly harmless condition (wet gun-cotton being quite unalterable) and at once used in that state as a powerful destructive agent through the agency of a detonating charge. The explosive action of wet gun-cotton is somewhat sharper than that of the dry material, the detonation being transmitted through its mass with greater rapidity in consequence of the displacement of air in its pores by the incompressible liquid. Gun-cotton, if it consists entirely of trinitrocellulose, does not contain sufficient oxygen for the complete oxidation of its carbon; hence more work can be accomplished with a given weight of gun-cotton if a solid oxidizing agent (a nitrate or a chlorate) be incorporated with it in proportion sufficient for complete oxidation. The compressed preparations (chlorated or nitrated gun-cotton) are as sensitive to detonation as gun-cotton itself, but are less sudden or sharp in their action. These preparations, first manufactured by Abel, were extensively experimented with some years ago, and one of them, prepared with barium nitrate, is now manufactured under the name of tonite for blasting purposes. Preparations allied to gun-cotton, in the production of which wood-fibre is used as the starting point, are manufactured for sporting and blasting purposes under the name of Schulze s

powder, sawdust powder, and patent gunpowder.
(f. a. a.)

GUNDULITSCH, Ivan (1588–1638), called Giovanni Gondola, one of the most celebrated Dalmatian poets, was born August 8, 1588, at Eagusa. His early education was superintended by two Jesuits, S. Muzzi and B. Bicasoli. the latter of whom instructed him in philosophy. At the age of twenty Gundulitsch applied himself to the study of j urisprudence ; and three years afterwards he was entrusted with a high official post in the Eagusan republic. Farther particulars of his life are not known ; he died December 8, 1638. Among his numerous poems the greatest is an epic entitled Osman u dvadeset pievaitjah (Osman in twenty cantos), printed for the first time at Eagusa in 1826, and reprinted at Agram in 1854, with a biographical sketch of the author by A. T. It was written to celebrate the victory of the Poles over the Turks and Tartars in the campaign of 1621. Cantos 14 and 15 are lost, having been suppressed by the Government of Eagusa on account of their writer s animosity against the Turks; but in their place others have been added by P. Sargo. An Italian version of this poem appeared in 1827. Of Gundulitsch s other poems, the Hymn on the Greatness of God and the Tears of the A fflicted Son, and his dramas the Rape of Proserpine and the Sacrifice of Love, deserve notice. He also made several metrical translations from the Italian poets. Gundulitsch s poems, besides their literary value, are specially interesting to a student of history, as they give a faithful picture of the time in which they were composed. A complete edition of his works, edited by V. Babukich, was published by thelllyrian university in 2 vols., Agram, 1847.

GUNDWANA, a form of the name Gondwana (q. v.).

 


GUNMAKING


 

UNDER this head falls the manufacture of every description of firearm, from the pistol to the 100-ton gun. The term " small arms " includes sporting and military weapons carried by the shooter ; instruments fitted for firing a rapid succession of bullets through one or more barrels from a rest are termed "machine guns;" while the heavier pieces, used exclusively in war, are denominated " ordnance."


Small Arms.


The date and circumstances of the introduction of portable firearms are involved in obscurity. No doubt many

attempts were made and failed previously, but gunpowder does not appear to have come into practical use as a rival to the crossbow for the propulsion of bolts or bullets till the reign of Edward III.; in 1375 mention is made of men armed with " gonnes " at an attack made on a Yorkshire manor-house. The arquebuse a meche was employed in Germany in 1378, and it is therefore probable that some rough weapon was introduced much earlier. The hand-gun (fig. 1) was used by both infantry and cavalry; it consisted of a simple iron or brass tube with touch-hole at the top, fixed on a straight stock of wood ; when used on foot, the soldier held it firmly by passing the stock under the arm; when used on horseback the stock was shortened to butt against the breast, the barrel resting on a fork secured to the saddle bow. About the beginning of the reign of Henry VII. the hand-gun was improved by the addition of a cock, which was brought down by a trigger to a pan at the side of the barrel; this cock held a match which ignited a priming in the pan, the priming communicating with the charge by a small hole. The next alteration consisted in the introduction of the wheel-lock, in which a steel wheel, rasped at the edge, protruded into the priming pan. Into the cock was fitted a piece of sulphuret of iron (pyrites) instead of a match; this was kept down to the priming pan

by a spring; another spring, when wound up, acted on the