116 MILITARY SCIENCES. 



charge was placed was made of smaller diameter (Jig. 16). From these 

 stone-pieces was derived the form of the mortar and the chambered guns of 

 modern times, the ancient ones having in section {fig. 22) a regularly curved 

 bore, diminishing uniformly from muzzle to breech. For bursting gates, &c.j 

 the petard was used {fig. 23), as soon as it was found out that powder, when 

 exploded, took effect in all directions alike, and gave, therefore, a recoil. 

 Such a petard consisted of a thick plank, the madrier, which was secured 

 fast to the gate it was desired to burst, and to this plank a metal pot, closed 

 on all sides and very thick, was attached, and filled with powder ; a slow 

 match, communicating with this powder, gave time, during its combustion, 

 for the person lighting the match to escape before the explosion, the whole 

 force of which being directed by the thick metal pot against the gate, burst 

 that open. Such petards are still used. 



After the superiority of firearms to all other projectile engines came to be 

 generally understood, the desire became active to construct them of such 

 weight and dimensions that they should be portable and manageable by the 

 single individual. This was effected only by degrees, and the first step was 

 to make cannon of very small proportions and very long, but still requiring 

 a light carriage ; these were called wall-pieces or culverines (fig. 6 a). The 

 great length of the bore and the unwieldiness of the carriage suggested the 

 idea of loading these wall-pieces from behind. The first contrivance for 

 this purpose was a breech-plate, which was screwed on after the charge was 

 inserted {fig. 6 h), and the gun fired by means of a red-hot wire run through 

 an orifice in this plate. This operation, however, consumed too much time ; 

 the touch-hole was contrived, and in the breech-plate itself a breech-screw 

 was inserted, which could be screwed in after the loading was completed 

 {fig. 6 d). Finally the tube and breech were made of one piece, and an 

 opening cut through the upper part of the tube ; through this opening the 

 charge was introduced, and it was then closed by means of a strong grooved 

 iron plug, in which was the touch-hole {fig. 6 c) and the piece discharged. 

 All these contrivances, however, accomplished their purposes so ineffec- 

 tually, and were so insecure and destructible, that they were soon laid aside, 

 and instead the piece made lighter and shorter. The first improvement in 

 this way is the swivel-gun, or field-hackbut {fig. 7), which was a kind of 

 light field-piece, but was principally used on the walls of fortresses, and in 

 other permanent positions. As our representation shows, the stand was a 

 tripod which could be raised or lowered, and on the head of which a fork 

 held the gun near the centre, while its breech was supported upon an arm 

 which was movable around the tripod, and had at the extremity a directing 

 screw. The part of the tube which held the charge was greatly strength- 

 ened to endure the force of the powder, to secure the gunner, and to throw 

 the whole power upon the ball. To make the direction and the aim more 

 certain, a sight was fixed upon this reinforcement, which was brought in 

 line with the head on the muzzle and the object to be hit. 



The next step in the improvement of firearms was the removal of the 

 piece from the fixed stand, and the first attempt of this kind was the arque- 

 bus {fig. 9). This had, instead of the carriage, a rather massive stock 

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