The people of Antwerp, after learning the success of their mine-ship, now did homage to the inventor with as much extravagance as they had a short time before mistrusted him, and they encouraged his genius to new attempts. Gianibelli now actually obtained the number of flat-bottomed vessels which he had at first demanded in vain, and these he equipped in such a manner that they struck with irresistible force on the bridge, and a second time also burst and separated it. But this time, the wind was contrary to the Zealand fleet, so that they could not put out, and thus the prince obtained once more the necessary respite to repair the damage. The Archimedes of Antwerp was not deterred by any of these disappointments. Anew he fitted out two large vessels which were armed with iron hooks and similar instruments in order to tear asunder the bridge. But when the moment came for these vessels to get under weigh no one was found ready to embark in them. The engineer was therefore obliged to think of a plan for giving to these machines such a self- impulse that, without being guided by a steersman, they would keep the middle of the stream, and not, like the former ones, be driven on the bank by the wind. One of his workmen, a German, here hit upon a strange invention, if Strada's description of it is to be credited. He affixed a sail under the vessel, which was to be acted upon by the water, just as an ordinary sail is by the wind, and could thus impel the ship with the whole force of the current. The result proved the correctness of his calculation; for this vessel, with the position of its sails reversed, not only kept the centre of the stream, but also ran against the bridge with such impetuosity that the enemy had not time to open it and was actually burst asunder. But all these results were of no service to the town, because the attempts were made at random and were supported by no adequate force. A new fire-ship, equipped like the former, which had succeeded so well, and which Gianibelli had filled with four thousand pounds of the finest powder was not even used; for a new mode of attempting their deliverance had now occurred to the people of Antwerp.
Terrified by so many futile attempts from endeavoring to clear a passage for vessels on the river by force, they at last came to the determination of doing without the stream entirely. They remembered the example of the town of Leyden, which, when besieged by the Spaniards ten years before, had saved itself by opportunely inundating the surrounding country, and it was resolved to imitate this example. Between Lillo and Stabroek, in the district of Bergen, a wide and somewhat sloping plain extends as far as Antwerp, being protected by numerous embankments and counter-embankments against the irruptions of the East Scheldt. Nothing more was requisite than to break these dams, when the whole plain would become a sea, navigable by flat-bottomed vessels almost to the very walls of Antwerp. If this attempt should succeed, the Duke of Parma might keep the Scheldt guarded with his bridge of boats as long as he pleased; a new river would be formed, which, in case of necessity, would be equally serviceable for the time. This was the very plan which the Prince of Orange had at the commencement of the siege recommended, and in which he had been strenuously, but unsuccessfully, seconded by St. Aldegonde, because some of the citizens could not be persuaded to sacrifice their own fields. In the present emergency they reverted to this last resource, but circumstances in the meantime had greatly changed.
The plain in question is intersected by a broad and high dam, which takes its name from the adjacent Castle of Cowenstein, and extends for three miles from the village of Stabroek, in Bergen, as far as the Scheldt, with the great dam of which it unites near Ordam. Beyond this dam no vessels can proceed, however high the tide, and the sea would be vainly turned into the fields as long as such an embankment remained in the way, which would prevent the Zealand vessels from descending into the plain before Antwerp. The fate of the town would therefore depend upon the demolition of this Cowenstein dam; but, foreseeing this, the Prince of Parma had, immediately on commencing the blockade, taken possession of it, and spared no pains to render it tenable to the last. At the village of Stabroek, Count Mansfeld was encamped with the greatest part of his army, and by means of this very Cowenstein dam kept open the communication with the bridge, the headquarters, and the Spanish magazines at Calloo. Thus the army formed an uninterrupted line from Stabroek in Brabant, as far as Bevern in Flanders, intersected indeed, but not broken by the Scheldt, and which could not be cut off without a sanguinary conflict. On the dam itself within proper distances five different batteries had been erected, the command of which was given to the most valiant officers in the army. Nay, as the Prince of Parma could not doubt that now the whole fury of the war would be turned to this point, he entrusted the defence of the bridge to Count Mansfeld, and resolved to defend this important post himself. The war, therefore, now assumed a different aspect, and the theatre of it was entirely changed.
Both above and below Lillo, the Netherlanders had in several places cut through the dam, which follows the Brabant shore of the Scheldt; and where a short time before had been green fields, a new element now presented itself, studded with masts and boats. A Zealand fleet, commanded by Count Hohenlohe, navigated the inundated fields, and made repeated movements against the Cowenstein dam, without, however, attempting a serious attack on it, while another fleet showed itself in the Scheldt, threatening the two coasts alternately with a landing, and occasionally the bridge of boats with an attack. For several days this manoeuvre was practised on the enemy, who, uncertain of the quarter whence an attack was to be expected, would, it was hoped, be exhausted by continual watching, and by degrees lulled into security by so many false alarms. Antwerp had promised Count Hohenlohe to support the attack on the dam by a flotilla from the town; three beacons on the principal tower were to be the signal that this was on the way. When, therefore, on a dark night the expected columns of fire really ascended above Antwerp, Count Hohenlohe immediately caused five hundred of his troops to scale the dam between two of the enemy's redoubts, who surprised part of the Spanish garrison asleep, and cut down the others who attempted to defend themselves. In a short time they had gained a firm footing upon the dam, and were just on the point of disembarking the remainder of their force, two thousand in number, when the Spaniards in the adjoining redoubts marched out and, favored by the narrowness of the ground, made a desperate attack on the crowded Zealanders. The guns from the neighboring batteries opened upon the approaching fleet, and thus rendered the landing of the remaining troops impossible; and as there were no signs of co-operation on the part of the city, the Zealanders were overpowered after a short conflict and again driven down from the dam. The victorious Spaniards pursued them through the water as far as their boats, sunk many of the latter, and compelled the rest to retreat with heavy loss. Count Hohenlohe threw the blame of this defeat upon the inhabitants of Antwerp, who had deceived him by a false signal, and it certainly must be attributed to the bad arrangement of both parties that the attempt failed of better success.