ORDNANCE (variant of ordinance, OF. or dinance, ordon a arc, ardor ma nee, Fr. ordon na ace, ordinance, from Lat. orditmrc, to order). The word ordnance is now commonly understood to comprise all cannon requiring a support or mounting of sonic form. The early projectile machine., the cross-bow. sling, catapult, and ballista. are related to modern cannon by the similarity of their purpose only. and have in principle of action and construction no bear ing upon the subject of ordnance. The blow gun. acting by compressed air, ha, some analogy with the modern pneumatic gun. but teaches no lesson of importance. The use of gunpowder cannon as factors of any consequence in war dates from the fourteenth century, during which period they were used beside the existing cata pults with. for some time. less actual effect. The first cannon were \vide-mouthed bowls. like an apothecary's mortar, called mortars, vases, bombards. etc. They gave little velocity to the stone projectile, and had little accuracy or power. They were made of bars (like barrel staves) wrapped and hooped to obtain necessary strength. Sonic were breechloaders. but were so crude that they were given up for the simpler muzzle-loader. The guns of this time had no trunnions, and many not even being fired from the ground. Some were mounted on blocks of to which they were lashed with no movement for aiming. Later improvements in shape were made. the bore being cylindrical with a narrow powder chamber, whereby the effect of the powder gas was more concentrated, the walls of the piece stronger, and the projectile always in the same position.
The fifteenth century witnessed increased use of cannon and many changes. The improvements in shape continued, and there was constant striving to increase size. Bombards were made as large as IS tons and fired stone projectiles as heavy as 901) pound,. Some were of 20-inch and even 2,5-inch bore. Some guns were in this century forged of iron in one piece—some in several, separable for transportation. Framed carriages were made, some having the gun lashed to a hinged which could be altered in eleva tion. France, 1461 to 14S3, made marked ad
vances. Trunnions were introduced; stone pro jectiles gave way to cast iron. with improvement in carrying power and effect, due to greater density, which. however, increased pressures and forced a reduction in calibre and a thickening of the walls of the cannon. Brass casting was generally adopted for gun construction, while carriages were developed to move with troops.
At the beginning of the sixteenth century guns were generally of brass. hut processes progressed sufficiently for them to he east of iron. These were found to be too heavy for field use. and a return to the lighter brass was made for those requiring mobility, which rule held until the middle of the nineteenth century. Cuts had handles and easeabels, and were much orna mented, and given individual as well as complicated class designations, depending upon the size and proportion of length to calibre. Dur ing this century the field-carriage limber was introduced. Case shot and explosive shell were used to some extent, but as the fuzes for the latter had to be lighted before insertion in the gun. many accidents occurred. Shell were first made of two hollow hemispheres fastened to. gether. (funs VIM' sometimes made of extreme length, as, for instance. 58 calibres. It was thought that the range increased with the length without limit.
To increase mobility. Gustavus Adolphus forth his 'leather gun' of thin copper wound with leather for strength. and afterwards used an iron 4-pounder weighing 650 pounds. Stationary carriages were made of wood sup porting the gun by trunnions and resting upon wooden wheels. Elevating was done by wedges under the breech, and change in direction was given by moving the carriage bodily. The Dutell introduced the howitzer, a cannon reduced to such length that shell could be put into it by hand. Gustavus Adolphus, in addition to his gun, introduced the method of inserting the powder charge in a package or cartridge. thus avoiding the danger and loss of time due to ladling it into the gun.