Two days later the army appeared before Aardenburg, a well-fortified town four miles south of Sluys. It surrendered disgracefully, without striking a blow. The place was a most important position for the investment of Sluys. Four or five miles further towards the west, two nearly parallel streams, both navigable, called the Sweet and the Salt, ran from Dam to Sluys. It was a necessary but most delicate operation, to tie up these two important arteries. An expedition despatched in this direction came upon Trivulzio with a strong force of cavalry, posted at a pass called Stamper's Hook, which controlled the first of these streams. The narrowness of the pathway gave the advantage to the Italian commander. A warm action took place, in which the republican cavalry were worsted, and Paul Bax severely wounded. Maurice coming up with the infantry at a moment when the prospect was very black, turned defeat into victory and completely routed the enemy, who fled from the precious position with a loss of five hundred killed and three hundred prisoners, eleven officers among them. The Sweet was now in the stadholder's possession. Next day he marched against the Salt, at a pass where fourteen hundred Spaniards were stationed. Making very ostentatious preparations for an attack upon this position, he suddenly fell backwards down the stream to a point which he had discovered to be fordable at low water, and marched his whole army through the stream while the skirmishing was going on a few miles farther up. The Spaniards, discovering their error, and fearing to be cut off, scampered hastily away to Dam. Both streams were now in the control of the republican army, while the single fort of St. Joris was all that was now interposed between Maurice and the much- coveted Swint. This redoubt, armed with nine guns, and provided with a competent, garrison, was surrendered on the 23rd May. The Swint, or great sea-channel of Sluys, being now completely in the possession of the stadholder, he deliberately proceeded to lay out his lines, to make his entrenched camp, and to invest his city with the beautiful neatness which ever characterized his sieges. A groan came from the learned Lipsius, as he looked from the orthodox shades of Louvain upon the progress of the heretic prince.