It was Cæsar’s opportunity to rise to the occasion, and he availed himself of the chance. Sending instructions to his officers to have a fleet built in the ports at the mouth of the Loire, he also raised oarsmen from the province and collected as many local pilots and seamen as possible. Thus, when the time came, the Roman fleet included ships impressed from the maritime tribes between the Loire and Garonne. The Roman engineers also came to the rescue, and, taking long poles, they armed them at one end with sharp-edged hooks. There was just one feature in which the galleys surpassed the stout ships of the enemy: they were far more mobile. So, when the rival fleets approached, two or more galleys ran alongside the Biscayan craft, thrust out the sharp hooks, caught the halyards, rowed hard away, with the result that the ropes snapped, the yard and sail came tumbling down on to the deck below and enveloped the crew. Springing smartly from the galleys on to this confused crowd, the enemy was soon slaughtered and the ship captured. In principle, though not in detail, the tactic was similar to that used in comparatively modern times when sailing men-of-war aimed to blow away the enemy’s rigging, leaving him so much out of control that complete annihilation was a matter only of time. But far more interesting than his expedition against the Veneti was Cæsar’s invasion of England. Regarded merely as a naval exploit, it is deserving of great attention; but to those who have had any experience of winds, waves, and tides it is most instructive. Picture Cæsar, therefore, in the summer of 55 B.C. at Gesoriacum, better known to the reader under its modern name of Boulogne. Here was a port that was important in even those early days. From this spot the merchants of Gaul were wont to embark their cargoes and carry them across the Channel to the shores of Kent, and later on it was destined to become one of the naval stations for the Classis Britannica. Think of it in the year we are speaking of as a busy place, lined with shipyards along its banks and many craft in its haven. From the forest above could be hewn and floated down the trees for the making of ships. Every mariner to-day knows that when the heavy north-east gales make it impossible for the cross-Channel packet-steamers to enter Calais, Boulogne can be entered with safety by even sailing craft. [Illustration: CHART TO ILLUSTRATE CÆSAR’S CROSSING THE ENGLISH CHANNEL.]