Page:Encyclopædia Britannica, Ninth Edition, v. 1.djvu/788

Rh 744 A M M A M M these are not of unquestionable authority. He un doubtedly originated the neo-Flatonic movement, but it cannot be determined to what extent that philosophy, as known to us through Plotinus and Proclus, represents his ideas. Eusebius (Church History, vi. 19) mentions some Christian works by Auimonius. As Porphyry expressly tells us that Ammonias the philosopher wrote nothing, Eusebius must be referring to the later Christian of the same name. To this later Ammonius belongs the Diates- saron, or Harmony of the Four Gospels, sometimes ascribed to the philosopher. (See Fabricius, Bibliotheca Grceca, v. 701, 713; and Zeller, Phil. d. Griechen, 2d cd., iii. 2, 308, note 6.) On Ammonius the philosopher, besides general works on the Alexandrian school and the history of philosophy, see Rosier, De Commentitiis Philosophize Ammoniacce Fraudibus ct Noxis, Tubingen, 1786; and Dehaut, Essai Ilistorique sur la Vie el la Doctrine d Ammonius Saccas, Brussels, 183G. AMMUNITION in its general sense comprises not only the powder and projectiles employed in guns of all classes, but also all stores directly connected with artillery fire, such as friction-tubes, fuses, percussion-caps, and rockets. Gunpowder, as manufactured in England, consists of 75 parts of saltpetre, 15 parts of charcoal, and 10 parts of sulphur, reduced to a fine powder and mechanically mixed together, pressed into a cake, and granulated to a size varying according to the purpose which it is designed to fulfil. In cannon, a large grain is necessary for regular and thorough burning, a fine powder choking up the inter stices, and so preventing the flame from finding its way through the entire charge. On the other hand, a large grain is blown out of a small piece before it is burnt to the centre. For the very heavy guns recently introduced into the British service powder formed into &quot;pellets&quot; or &quot; pebbles &quot; has been adopted, by which the pressure of the gas is kept up till the shell leaves the muzzle, without being at any instant excessive and likely to injure the gun. Modified forms of powder and gun-cotton have been employed experimentally as the charges of guns. For heavy guns or cannon the charge is carefully weighed and made up in a serge cartridge sewn with worsted, which entirely consumes in firing any residue left ignited in the bore being liable to cause explosion when the cartridge of the succeeding round is rammed down on it, and so to blow off the arms of the gunner using the sponge stave. The shell or other projectile employed is forced home on the cartridge (vide fig. 1) in muzzle-loading guns. In breech-loaders the shell is introduced first, and pressed into the shot chamber, beyond which it can only pass by the &quot; lands &quot; of the rifling cutting into the lead coat, which is effected by the explosion of the charge. The cartridge is pressed forward against the base of the projectile. Rifled guns that is, guns constructed to impart rotation to the projectiles they discharge have superseded smooth- bored cannon in the armaments of all civilised nations ; elongated projectiles, which are impeded by the resistance of the air much less than spherical ones, being in all cases employed. Fig. 1 shows a section of the bore of the Fio. L 1, 1, wi -ought-iron coils ; 2, steel ; 3, copper studs ; 4, worsted braids. muzzle-loading gun, whose projectiles are made to rotate by means of gun-metal studs which fit in the spiral grooves of the bore. The following kinds of projectiles are fired from rifled cannon in the British service : Common shell, Shrapnel shell, Palliser shell and shot, and case-shot. Light balls, carcasses, and spherical shells are discharged from smooth-bored mortars. The two last mentioned, as well as spherical Shrapnel, round shot, grape, and case, are fired from smooth-bored guns. Common shell for rifled guns are simply hollow elongated projectiles filled with powder, which is fired by the action of a fuse, and bursts the shell with great violence, acting in walls or earth into which it has penetrated like a small mine, the largest shells, which are twelve inches in diameter, containing nearly 37 Ib of powder. Gun cotton, nitro glycerine, and other substances, have been tried for burst ing purposes, but it has been found very difficult to prevent premature explosion from the sudden shock of discharge of the gun. Picrate of potash, or &quot; picric powder,&quot; has been recommended as stronger than gunpowder and quite cafe, but it is not as yet adopted. Common shells are generally fired at earthworks, buildings, and wooden ships. When carried, as in English men-of-war, filled and fused with percussion fuses, they can be discharged as rapidly as shot. The most terrible instance of their use in history is the entire destruction of the Turkish frigates by the Russian fleet at Sinope on November 30th, 1853. At the battle of Sedan in 1870 the Prussians made such havoc among the crowded French troops that the ground became covered with &quot; heaps of flesh and rags ; &quot; and a similar result was produced by the fire of mortars concentrated on the Russian troops in the Redan at the termination of the siege of Sebastopol. The slaughter in the two last named instances is, however, to be attributed to the concentration of fire on masses of men rather than to the description of shell used, for the showers of bullets ejected by Shrapnel shell would have struck many more men, although the ghastly spectacle of dismembered human bodies would not have been exhibited. Shrapnel shell are hollow projectiles containing bullets and a very small bursting charge. Fig. 2 exhibits construction of the Boxer Shrapnel shell for the 40-pounder breech-load ing Armstrong gun, and is a good specimen of this class of projectile. The shell follows the usual course of flight up to within about 100 yards of the object, when the time fuse, if properly set, fires the bursting charge, and opens the shell by splitting it along certain grooves forming lines of least resistance. The bullets and fragments then continue their course in the form of a shower of missiles. This class of shell was designed for smooth-bore guns by General Shrap nel. It was used with great effect during the Peninsular war, especially in clearing the breach and ramparts of St Sebastian of defenders, over the heads of the English storming party, who drew back into the ditch for a time. The projectile has never been understood and thoroughly t^Vpn nn bv fnrpimi rtnwprs and Ivis FW. 2. 2, 3, copper parts; 8, taKen up oy it reign powers, an a, gun metal; 4, 4, wrought- never been used to full advantage iron or mild steel ; 5, lead j on service. In skilful hands it is 6&amp;gt; papei - capable of producing results far beyond any that have as yet been achieved. The Armstrong segment shell fulfills the same general purpose, that is to say, it is designed to sweep down bodies