But it is in the galleries within that we must seek for those records of primitive habitation that we have come to see. Hatchets of silex or of bronze, rude clay vases that were found nine yards beneath the soil, bear witness to the remotest ages of humanity in Rouen. The town grew very slowly, for its name was unknown in any form to Caesar, and it is not till the second century that Ptolemy mentions Rotomagos as the capital of the tribe of Velocasses who have left their name to the Vexin. The unhealthy marshes in the valley between the hills and the river were not likely to be tenanted by the first Roman conquerors who fixed their centre at Julia Bona, and their amphitheatre may still be seen, near the ruins of a Norman castle, in the midst of the manufactories of Lillebonne. But as the importance of Lutetia grew upon the upper waters of the Seine, the value of this elbow of the stream grew greater every year; and by the days of Diocletian, Rotomagus had become the sea-gate of the capital, and the chief town of the province. Already Strabo speaks of its commerce with the English ports, and it appears as the natural point of exchange between southern civilisation and the barbarism of the north, the gate through which goods came from Italy, travelling by Rhone, by Saone, or Seine, to England. Its first fortifications found a natural southern base upon the river's bend; to east, to west, and north it was protected by hills and by the marshes, and unhealthy as it was, the Roman colonists were compelled, when danger came, to leave the Julia Bona they preferred in peace, and fly for safety to the fine strategical position Nature had marked out at Rouen. Here, too, was the home of the Provincial Governor, and of his military captain; and of the walls they built the eye of faith can still see traces at the Ponts de Robec, at the Abbaye de St. Amand, near the Hotel de France, close to the Priory St. Lo, and in the Place Verdrel in front of the Palais de Justice. I have marked out the limits of this earliest _castrum_ on Map C; and in the Rouen of to-day you may see a strange confirmation of the fact that Roman Rotomagus was a far more watery place than may be realised at first. For if you stand anywhere about the level of the Cathedral foundations and look in the direction of the river, you will notice that all the streets slope upwards. Go nearer still, and at the angle where the Rue du Bac meets the Rue des Tapissiers, the upward slope becomes even more pronounced, for though the river is not so far away, there is even less of it to be seen. A great embankment has been slowly built; and upon what was once marshland and islands and the tidal mud, has grown up nearly all that part of Rouen which lies between the Cathedral and the river.