At this critical moment, by means of Austrian fireships suddenly sent down the swollen and rapid river, the bridge connecting the island of Lobau with the right bank was wholly swept away. Buonaparte perceived that if he wished to preserve his communications with the right of the Danube, where his reserve still lay, he must instantly fall back on Lobau; and no sooner did his troops commence their backward movement, than the Austrians recovered their order and zeal, charged in turn and finally made themselves masters of Asperne. Essling, where Massena commanded, held firm, and under the protection of that village and numerous batteries erected near it, Napoleon succeeded in withdrawing his whole force during the night. On the morning of the 23rd the French were cooped up in Lobau and the adjacant islands--Asperne, Essling, the whole left bank of the river, remaining in the possession of the Austrians. On either side a great victory was claimed; and with equal injustice. But the situation of the French Emperor was imminently hazardous: he was separated from Davoust and his reserve; and had the enemy either attacked him in the islands, or passed the river higher up, and so overwhelmed Davoust and relieved Vienna, the results might have been fatal. But the Archduke's loss in these two days had been great; and, in place of risking any offensive movement, he contented himself with strengthening the position of Asperne and Essling, and awaiting quietly the moment when his enemy should choose to attempt once more the passage to the left bank, and the re-occupation of these hardly contested villages. Napoleon availed himself of this pause with his usual skill. That he had been checked was true, and that the news would be heard with enthusiasm through Germany he well knew. It was necessary to revive the tarnished magic of his name by another decisive battle: and he made every exertion to prepare for it. Some weeks, however, elapsed ere he ventured to resume the offensive. On the 4th of July he had at last re-established thoroughly his communication with the right bank, and arranged the means of passing to the left at a point where the Archduke had made hardly any preparation for receiving him. The Austrians, having rashly calculated that Asperne and Essling must needs be the objects of the next contest as of the preceding, were taken almost unawares by his appearance in another quarter. They changed their line on the instant; and occupied a position, the centre and key of which was the little town of Wagram.