The number of oars in an ancient trireme was as many as 170. These oars were necessarily very long, and time was kept sometimes by the music of a flute, or by the stroke set by the _keleustes_, who was on board for that purpose. This he did either with a hammer of some sort, or his voice. And there is at least one illustration showing such a man using a hammer in an oar-propelled boat for that purpose.[7] The inscriptions which were unearthed some years ago, containing the inventories of the Athenian dockyards, belonging to the years between 373 B.C. and 323 B.C., have been collected and published. And it is from them that we obtain such valuable information as the number of oarsmen which the biremes carried. This number was usually 200, and was disposed in the ship as follows: There were 54 _thalamitai_, 54 _zugitai_, 62 _thranitai_, and 30 _perineo_. The exact meaning of the latter word is supercargoes or passengers, but they were carried perhaps as spare oarsmen in case any became disabled. All oars were worked together against the tholes, and as we know from the old depictions there was a space left both at bow and stern beyond the oarsmen, this space being called the _parexeiresia_. The number of oarsmen just mentioned may seem very large, but having regard to the speed required for manœuvring and for ramming effectively it is not excessive. But when a war-vessel was employed on transport duty so great a host of men was not essential. In the case of a vessel engaged, for instance, in carrying horses in her hold only sixty oarsmen were needed. Had you found yourself alongside one of the war-galleys you would have been struck by its length and leanness more than by anything else. As you passed round by the bows you would have observed the two great eyes, one on either side of the hull, through which in all probability the hawsers passed. Behind these two eyes were very substantial catheads which projected like great ears from the ship, and were used primarily for slinging the anchors just as in the old-fashioned sailing ships of Nelson and after; but, secondly, for convenience when ramming. Thus, when the terrible shock came, the catheads would protect the oars of the ship from damage and allow the utmost speed to be maintained till the last minute--a factor that was naturally of the highest importance. But also they were sometimes strengthened with supports so that they might catch in the topsides of the enemy and do him considerable damage.