Layard’s reproduction shows that biremes have existed since the earliest times. It must not be forgotten, in this connection, to invite attention to the Greek “Dipylon” vases on which two banks of superposed oarsmen are shown. These reproductions are, however, so primitive that it seems to me hazardous to deduce any conclusions from them. As a matter of fact, it may be assumed up to a certain point that the upper bank of oarsmen represents the after bank and that, instead of being superposed, one set of oarsmen followed after the other.
The oars of the upper bank are not drawn in full, which shows that the rowers followed one another and were not placed the ones above the others. It is deduced from this that all these drawings should be accepted with the greatest circumspection.
In the Middle Ages, there were several oarsmen to an oar; more reliance was placed on a more rapid movement of the oars than on the increase of their numbers, to obtain a greater speed.
It cannot be said exactly when the transition was brought about. But the oldest method of propulsion is, in any case, the one in which each oar was worked by a single man for a single oar; it was taken, so it would seem, from the boats using paddles, each paddle being handled by one man.
The relative positions, which might be taken by the rowers who worked superposed banks of oars, have given rise to many suppositions which it is superfluous to examine in detail.
Nothing more will be done than to recall the trials of propulsion by oars, undertaken on the initiative of the Emperor Napoleon III, on a galley built especially for these experiments. It was shown that the trireme was a possible thing but, that a boat of this sort was so encumbered by rowers that no space was left for the cargo. (See the work Le Musée du Louvre, “Constructions navales dans l’Antiquité.”)
The result of the researches made may be stated as follows:
All the ideas put forth in regard to the number of banks of oars and to the respective places occupied by the oarsmen rest only on hypotheses. There have been more than one bank of rowers, but it is probable, however, that it was exceptional when there were more than two. Each oar at the beginning was handled by a single man. (Encyclopædia Britannica, 9th Edition, p. 806; HOLMES, p. 44; TORR, p. 18; WITSEN, p. 13.)
As a general rule, vessels moved by oars underwent little change after the invention of gunpowder. The propelling force could not be developed because it was not possible to increase the number of oars without trouble (Archéologie Navale, A. JAL, Vol. I, p. 50; Dictionnaire des Antiquités grecques et romaines, p. 40; idem p. 30).
So, JAL, in the “Archéologie Navale”, refuses to admit that there were ships as large as the “Great Eastern” in the times of the Greeks and Romans.