Albert's leading thought however was to cut off the supplies. The freaks of nature, as already observed, combined with his own exertions, had effectually disposed of the western harbour as a means of ingress. The tide ebbed and flowed through the narrow channel, but it was clogged with sand and nearly, dry at low water. Moreover, by an invention then considered very remarkable, a foundation was laid for the besiegers' forts and batteries by sinking large and deep baskets of wicker-work, twenty feet in length, and filled with bricks and sand, within this abandoned harbour. These clumsy machines were called sausages,21 and were the delight of the camp and of all Europe. The works thus established on the dry side crept slowly on towards the walls, and some demi-cannon were soon placed upon, them, but the besieged, not liking these encroachments, took the resolution to cut the pea-dyke along the coast which had originally protected the old harbour. Thus the sea, when the tides were high and winds boisterous, was free to break in upon the archduke's works, and would often swallow sausages, men, and cannon far more rapidly than it was possible to place them there. Yet still those human ants toiled on, patiently restoring what the elements so easily destroyed; and still, despite the sea; the cannonade, and the occasional sorties of the garrison, the danger came nearer and nearer. Bucquoy on the other side was pursuing the same system, but his task was immeasurably more difficult. The Gullet, or new eastern entrance, was a whirlpool at high tide, deep, broad, and swift as a millrace. Yet along its outer verge he too laid his sausages, protecting his men at their work as well as he could with gabions, and essayed to build a dyke of wicker-work upon which he might place a platform for artillery to prevent the ingress of the republican ships.