On the morning of the 25th of November the weather, hitherto fine, suddenly changed. About nine a fine snow fell, and was soon after followed by a deluge of rain, accompanied by squalls. During the night of the 15th, the men on guard in the trenches were up to their knees in water; it was impossible to work. The rain continued regular and heavy during the whole of the 16th. Rincourt took advantage of this disagreeable state of the weather. The bridge which had been thrown across the river by the Imperialists, below the stone bridge, consisted of a floor six feet wide, laid partly on trestles, partly on boats collected in the valley and linked together. This was a clumsy contrivance, for the water on beginning to rise lifted the boats proportionately so that it was extremely difficult to maintain the connexion between the floor resting on the boats and that laid on the trestles. Accordingly in spite of the rain the besiegers worked all day on the 16th to prevent the rupture of this bridge. The governor who passed all that day in examining the environs, had perceived from the top of the platform of the cavalier the precarious condition of the besieger's bridge, and at night he had some large trunks of trees thrown over the parapet of the stone bridge, which struck against the boats and trestles and impeded the current, which kept on rising. At midnight twenty of these trunks had accumulated against the boats, and the river continuing to rise, the bridge was carried away. A light appearing for an instant at a certain point of the valley of Abonne apprised Rincourt of the destruction of the bridge. The signal was given by one of the spies.