In the ancient vessel the tiers of oarsmen must have sat in nearly the same vertical plane, obliquely arranged, one behind and below the other. Thus in the bireme the zygite, as he sat on his bench, had behind him and below him his thalamite whose head was about 18 inches behind the zygite thwart and a little above it. Moreover, as his seat was now a little raised, the zygite required an _appui_ for his feet, which was formed for him on the bench on which the thalamite next below and in front of him was sitting; on either side of him his feet found a resting-place. As the zygite fell back during the stroke and straightened his knees, there was plenty of room for the thalamite below to throw his weight also on to his oar. There seems to have been but little forward motion of the body. The arms were stretched out smartly for the recovery, as we learn from Charon's instructions to Dionysus in the 'Frogs' of Aristophanes, and then a _driving smiting_ stroke was given (cf. the words [helahynein, pahiein, hanarrhiptein hala pedo]) and the brine tossed up by the blade. When once the principle had been established, by which additional power could be gained without increasing the length of the vessel, and had been tested by practical experience, its development was sure to follow. What century witnessed the birth of the trireme is not certain, but probably by 800 B.C. the earliest vessels of this description had been launched. The quick-witted sharp-eyed Greek was not slow to copy, and by the beginning of the next century the busy shipwrights of Corinth were building the new craft for Samians as well as for themselves. It is, however, in the Attic trireme such as composed the fleets of Phormio and Conon that historical interest has centred, and though quinqueremes were commonly in use in the second and third centuries, B.C., and even still larger rates of war vessels constructed till they were _inhabilis prope magnitudinis_, unwieldy leviathans, such as the sixteen-banked flagship of Demetrius Poliorcetes, yet the interest in the trireme has never failed, and the splendour of its achievements has insured to it an attention on the part of the learned which no other class of vessel has been able to attract to itself. The problem of construction of the trireme, and of the method of its propulsion, has exercised the ingenuity of scholars ever since the revival of letters. It has a literature of its own, and it may fairly be said that if the enigma has not been solved, it is not for want of industry or acumen.