523 MILITARY PROJECTILKS. 



only in the trifling difference of the purposes to which 

 they were applied. The sling being intended to throw 

 a stone, and the dart, a sort of arrow. 



'3. The third class comprises those in which the elas- 

 tic force of various substances is applied to the projec- 

 tile. The bow and arrow is the simplest instrument of 

 this kind, and it was for a long time in earlier ages, one 

 of the most important means of warfare. Hand-bows 

 were constructed of various materials, and fitted up in 

 very various ways. The accuracy with which they may be 

 aimed, and the greater velocity which may be given to the. 

 projectile, enabled them to take a high rank in the time 

 when they were introduced. 



As men advanced in the arts of life, and began to feel 

 the necessity of having some permanent means of de- 

 fence, walls and fortifications of various kinds began to 

 be erected, which were for a long time an effectual secu- 

 rity from violence. The same principle, however, with 

 that which gives its efficiency to the bow and arrow, soon 

 afforded the means of successful attack against these. 

 The engines so frequently mentioned in ancient history 

 under the names of Balista Catapulta Oneiger, &.c, 

 were variously constructed ; but the force was usually 

 the elasticity of twisted ropes. The construction and 

 the employment of these and similar engines, continued 

 for some time in the middle ages. They received various 

 names, and were variously modified according to the in- 

 genuity, or the particular purposes of the engineers who 

 prepared them. 



It is not possible to ascertain now with any accuracy, 

 what was the form, or how great the power of these en- 

 gines. The most exaggerated accounts of their magni- 

 tude and effects have descended to us, and whatever de- 

 duction it is necessary to make from these, it is doubt- 

 less true, that immense stones, and beams of wood, and 

 other ponderous missiles of great size were thrown by 

 these machines with great force and effect. The follow- 

 ing extract from Plutarch's account of the siege of Syra- 

 cuse, will illustrate the use of these and similar engines. 



' Archimedes one day asserted to king Hiero, whose 

 kinsman and friend he was, this proposition, that with a 



