ARTILLERY 253 



which that curve necessitates ? That gunpowder varies in explosive power in this 

 way in mines, shells, or torpedoes, or anywhere, except in a stud-rifled gun, is stoutly 

 denied. If the variation of powder-pressures be not due to the gunpowder it must 

 be due to the shot ; and if to the shot, then to the oscillations of the axis round the 

 points of contact with the bore, which are exclusively the studs ; but the studs are a 

 necessity of the increasing spiral or parabolic groove. Hence it appears, that, while 

 saving '12 of a ton pressure on the square inch, by employing this most unmechanical 

 contrivance, we are adding at least 4 tons, and, probably, more, pressure occasionally 

 to the gun. These are the deductions which we draw from Captain Noble's formulas, 

 and from the Koport of the Committee on Explosives.' Iron. 



After the siege of Paris inquiries and experiments were made in all directions into 

 the relative qualities of bronze and steel for cannon ; amongst the metals tried was 

 phosphorised bronze, of which MM. Montefiore, Levy and Kunzel claimed to bo the 

 inventors. This claim is now refuted, and it appears that sixteen years ago the very 

 same alloy was introduced to the French artillery by two officers, MM. do Koulz and 

 A. de Fontenay. In the years 1870 and 1871 a series of experiments were made at 

 Liege, in presence of a commission of artillery officers of all nations, and the results 

 were described in a pamphlet by M. LeVy, as highly favourable to the alloyin question. 

 It is stated in that work, that an ordinary bronze gun founded at Liege, having been 

 fired forty-nine times with a charge of one kilogramme of powder and a shot, was so 

 seriously injured that it was impossible to continue the experiments with it, while another 

 gun of the same calibre (4) made of the new phosphorised bronze, and fired with the same 

 charge, and the same number of times, exhibited no sensible injury whatever. Fur- 

 ther comparative trials with bursting charges gave results equally favourable to the 

 new metal. In this case, guns of each kind were fired under the same conditions, five 

 times each, commencing with one kilogramme of powder and a single shot, and carried 

 as high as 1 J kilogrammes, with a cylinder of the weight of 3 shot, with one charge 

 of 14 kilogrammes of powder, and 2 shot, and still more so with the same amount of 

 powder, and a cylinder equal to 3 shot. The interior of the chamber of both guns 

 was visibly enlarged, but rather more so in the case of the old than of the new metal 

 gun. Finally, the phosphorised bronze gun burst with a charge of 1^ kilogrammes of 

 powder, and a cylinder of equal weight. These experiments seemed conclusive, but 

 the French Government ordered further trials to be made at Bourges and other places 

 by a commission of artillery officers, with bronze guns of various alloys, and of foreign 

 as well as French make. The results as between ordinary and phosphorised bronze 

 are very different from those obtained at Liege. 



The projectiles used at Bourges were long solid shot, weighing from 10 kilogrammes 

 to 20 kilogrammes for guns of 4, with charges of powder ranging from the ordinary 

 quantity to 1,700 grammes, the bursting charge. With a charge of 1,150 grammes, 

 and a 10-kilogramme shot, the phosphorised bronze gun began to show cracks, while the 

 ordinary gun exhibited no serious injury whatever. The experiments wore after- 

 wards continued with full charges of powder and 20-kilogrammes projectiles : at the 

 seventeenth or eighteenth firing the phosphorised bronze gun burst, and produced a 

 number of small fragments, without any appearance of enlargement of the circum- 

 ference. At the nineteenth round, the ordinary bronze-metal gun also burst, nearly half 

 the piece being blown off in one mass, which, as well as the rest of the gun, exhibited 

 expansion of the metal with longitudinal fissures. The conclusion the Commission 

 arrived at, after these absolutely conflicting results, was, that the ordinary bronze used 

 for guns exhibits at least as much resisting power as phosphorised bronze, and is in- 

 comparably more malleable and less brittle. 



SHELLS. The hollow explosive projectiles that we call shells, or bombs, are a very 

 old invention. Under the name of ' coininges,' they consisted of rudely formed globes 

 of plate-iron soldered together, filled with gunpowder and all sorts of miscellaneous 

 'mitraille.' These were thrown to short distances both from ' pierriers ' (a sort of 

 mortar) and from catapult*, as early as 1495 at Naples, 1510 at Padua, 1520 at Heils- 

 berg, 1522 at Khodes, and 1542 at Boulogne, Liege. About the middle of the 15th 

 century bombs of cast-iron seem to have come into use ; an Englishman, named 

 Malthus, learned the art of throwing them from the Dutch, and perfected the system 

 for the French armies -being the first to throw shells in France, at the siege of La 

 Mothe, in 1643. The diameter of the bomb seems at that time to have become fixed 

 at 13 inches the old Paris foot; and at this it remains (with very few exceptional 

 cases) down to the present day. 



A few attempts to increase the size and power of these projectiles have been made 

 at different periods, but never with the practical skill necessary to success; for 

 example, 18-inch shells were thrown by the French at the sioge of Tournay, in 1745 ; 

 whereas, just a century before, the Swedes threw shells of 462 Ibs. weight, and 



