The shield worn by the heavy-armed infantry was not round, like that of the early Greeks, but oval or oblong, adapted to the shape of the body, such as was adopted by Philip and Alexander, and was made of wood or wicker-work.  The weapons were a light spear, a pilum, or javelin, over six feet long, terminated by a steel point, and a short cut-and-thrust sword with a double edge.  Besides the armor and weapons of the legionary, he usually carried on the marches provisions for two weeks, three or four stakes used in forming the palisade of the camp, besides various tools,—­altogether a burden of sixty or eighty pounds per man.  The legion was drawn up eight deep, and three feet intervened between rank and file, which disposition gave great activity, and made it superior to the Macedonian phalanx, the strength of which depended on sixteen ranks of long pikes wedged together.  The general period of service for the infantry was twenty years, after which the soldier received a discharge, together with a bounty in money or land.

The cavalry attached to each legion consisted of three hundred men, who originally were selected from the leading men in the State.  They were mounted at the expense of the State, and formed a distinct order.  The cavalry was divided into ten squadrons.  To each legion was attached also a train of ten military engines of the largest size, and fifty-five of the smaller,—­all of which discharged stones and darts with great effect.  This train corresponded with our artillery.

The Roman legion—­whether it was composed of four thousand men, as in the early ages of the republic, or six thousand, as in the time of Augustus—­was divided into ten cohorts, and each cohort was composed of Hastati (raw troops), Principes (trained troops), Triarii (veterans), and Velites (light troops, or skirmishers).  The soldiers of the first line, called Hastati, consisted of youths in the bloom of manhood, who were distributed into fifteen companies, or maniples.  Each company contained sixty privates, two centurions, and a standard-bearer.  Two thirds were heavily armed, and bore the long shield; the remainder carried only a spear and light javelins.  The second line, the Principes, was composed of men in the full vigor of life, divided also into fifteen companies, all heavily armed, and distinguished by the splendor of their equipments.  The third body, the Triarii, was composed of tried veterans, in fifteen companies, the least trustworthy of which were placed in the rear; these formed three lines.  The Velites were light-armed troops, employed on out-post duty, and mingled with the horsemen.  The Hastati were so called because they were armed with the hasta, or spear; the Principes for being placed so near to the front; the Triarii, from having been arrayed behind the first two lines as a body of reserve.  The Triarii were armed with the pilum, thicker and stronger than the Grecian lance, four and a half feet long, of wood, with a barbed head of iron,—­so