Captain GREY directed Lieutenant BACON to patrol towards the house, while he remained with the remainder of the Troop, concealed from the Enemy's view, a disposition favoured by the nature of the ground, and the trees in the hedges, on both sides of the road. When Lieutenant BACON's party moved forward, it was discovered by the Vedette, who began circling, and fired his carabine. The French Picquet posted in the house instantly rushed out; several of the men had their jackets and accoutrements off; and the Post could easily have been captured, had the special duty on which the British Patrol was engaged admitted of an attack. The French turned out very quickly and galloped to the rear along the high road, while BACON's party was recalled. A few French Cavalry galloped up to the Vedette on the Heights, but evinced no disposition to advance. It had now become sufficiently evident that, commencing from this point, the French were in possession of the Namur road; but the principal object which Sir ALEXANDER GORDON had in view was yet to be attained. The Patrol now retired a little until it reached a cross road, which a peasant pointed out as the Prussian line of retreat. Pursuing this track, the Patrol, within an hour, reached Tilly; where General ZIETEN, who had been placed in temporary command of the Cavalry, was covering the retreat of the Prussian Army. After remaining here about a quarter of an hour, during which Sir ALEXANDER GORDON obtained from General ZIETEN the most ample information respecting the movements of the Prussians, the Patrol commenced its return, at a quick pace, striking into a cross road, which joined the high road at a point nearer to Quatre Bras than the one whence it had quitted it. The Patrol reached Quatre Bras at about half past seven o'clock; and Sir ALEXANDER GORDON immediately reported to the Duke that the Prussians had retreated towards Wavre, that the French occupied the ground on which the Battle had been fought; but that they had not crossed the high road, along which the Patrol had proceeded almost into the immediate vicinity of their Advanced Posts. This latter circumstance was very remarkable, and served to satisfy WELLINGTON that, either NAPOLEON's victory had not been followed up with a vigour and an effect, by which the safety of his own Army would have been perilled, or, that it had not been of a character sufficiently decisive to have enabled the French Emperor to avail himself of such a vantage ground.