[152] Again there are other appellations which differ from one another, but still signify but one thing, as a shaft, a bolt, and arrow; for all these terms are applied to the weapon which is sent from the string of the bow against the mark; and again there are the words, oar, scull, and blade, to express the instrument used for propelling a vessel, of equal power with sails; for whenever a ship, by reason of a calm or of unfavourable winds cannot use its sails, then, those, whose business it is, sitting down as rowers, and stretching out their oars on each side like wings, compel it to proceed onwards as if borne on wings; and so the vessel being borne on the top of the waves, and rather running over them than cutting through them, hastens along with a speedy voyage, and speedily anchors in a safe harbour.