The influence of the Roman navy on land was seen in a manner similar to that in which the Roman army influenced gladiatorial combats. In Rome there were various “naumachiæ,” which were great reservoirs surrounded by seats like an amphitheatre and were specially constructed for holding naval fights. There was one, for instance,[14] built by Augustus on the trans-tiberine side of the river, and traces of this naumachia were discovered not many years ago. A naumachia consisted of an enormous tank or lake excavated in the ground, and measured 1800 feet long by 1200 feet wide. Within this ample area naval battles containing thirty beaked ships with three or four tiers of oars, together with many other smaller ships were engaged, and no fewer than three thousand fighting men, to say nothing of the rowers, were engaged. It is interesting to add that naval fights were also held in a gigantic reservoir on the site now occupied by the Colosseum. [Illustration: REPRESENTATION OF A ROMAN NAUMACHIA. (See text.)] No consideration of the relation of Rome to the sea can be complete without taking into consideration those important and daring adventures which Julius Cæsar attempted. Adventures they certainly were, for here was a land general trying experiments which belonged rightly to sailormen; and, as was the inevitable result, he made terrible mistakes as he blundered through towards victory. His expedition against the Veneti, “the stoutest and the most skilful seamen in Gaul,” taught him much: taught him that he was matched to play a game whose tricks he did not understand. But the praise belongs to him, a landsman, for his ingenuity and resource in toiling with such signal success against very heavy odds. He recognised quickly that the ships of the Veneti and their allies were so heavy that no Roman galley with its cruel rams could have any appreciable effect on them. They were too high out of the water, too, to enable the legionaries to hurl their missiles with any telling effect. It has been suggested that the design of these powerful Biscayan craft had originally been borrowed from the great Carthaginian merchantmen, “whose commerce in British waters they had inherited, and their prosperity depended upon the carrying trade with Britain, of which they possessed the monopoly.”[15]