110 MILITARY SCIENCES. 



The heavy catapult {jig. 5) projected arrows of six feet in length and sixty 

 pounds' weight to the distance of about four hundred paces. This catapult 

 had no proper bow, but two pieces of plank, a, a, which were inserted 

 between strong ropes, c, c, in the main frame, and those ropes so twisted by 

 means of the racket wheels, d, d, that the ends of these planks pressed 

 powerfully against the cushions, m, m. If now, by means of the windlass, y, 

 and the hook fastened to it, the bow string, which was made of twisted 

 hifle, was drawn strongly backwards, the ropes at c c were thereby still 

 more sharply twisted together, and when the string was suddenly let loose, 

 it drove the arrow, lying in its groove, r, r, with great violence before it. 

 Afterwards the two pieces, a, a, were replaced by a strong steel bov/. Of 

 the ballistae there were also lighter kinds for field use, and heavier for siege 

 service. The field ballista {pi. 33, fig. 6) was placed upon a light car, and 

 consisted of a strong frame, having between its uprights a twisted rope, as 

 seen in our common w^ood saw ; and in the twist of this rope, as the key, a 

 ladle at the end of a strong handle. This ladle is drawn back by means of 

 a rope, a stone laid in it, and the draw then suddenly let go, when the 

 ladle strikes with violence against the cap of the frame, and the stone is 

 projected with great force by the impulse it has received, with so much the 

 greater, indeed, as the rope is more strongly twisted. Another kind of 

 field ballista is the sling ballista {fig. 7) and {pi. 34, figs. 3, 4). Beside a 

 groove made of planks stands a post, upon which is a cross-beam with pins at 

 the ends ; on these pins a fork moves, at the ends of which are fastened boxes 

 loaded with weights or stones. The bow of the fork bears a long handle, 

 reaching downwards to the groove, at the extremity of which is attached an 

 ordinary stone sling. When, by means of a rope and small winch on the 

 ground, the long arm of the lever is drawn down {fig. 3 and pi. 33, fig. 7) 

 and the sling is loaded, the draw rope is let loose, and the counter weights, 

 which have attained their highest elevation, pull the handle suddenly 

 upwards, and thus the sling is discharged {pi. 34, fig. 4). The heavy 

 ballistee are like the light, only much larger. Pi. SS,figs. 8 and 9, represent 

 such siege ballistse. a, a, a, is the ground frame upon which the uprights, 

 B, B, are erected, on whose cap, at e, is a projection, against which the 

 handle, c, of the ladle, s, strikes when it flies up, to give the back stroke. 

 The handle, c, is twisted into a rope, which is tightened on each side by 

 means of the racket wheels, q, which are turned by the racks, x, and held 

 in place by the stops, y. In order to set the ballista, a rope is attached 

 just below the ladle, s, and wound round the roller, t, which is turned by 

 handspikes, and held in place by a racket wheel. As soon as the ladle is 

 charged, the rope is let loose and the ladle flies up {fig. 9). With such 

 ballistae, stones of from ten to three hundred and sixty pounds' weight were 

 hurled. Archimedes, indeed, constructed ballistae which threw stones of 

 ten hundredweight ; quantities of heavy leaden balls were also discharged 

 from the ballistae. A smaller ballista for fire balls is shown, pi. 34, fig. 5. 

 Fire arrows were shot by the catapult. 



b. Battering Engines. The most ancient and simplest wall breachers 

 are the wall borers, by means of which the joints of a fortress wall were 

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