PIRCH's Corps (the Second) broke up from its position between St Anne and Aisemont, on the right bank of the Dyle, about noon, for the purpose of passing the Defile of Wavre. The 1st Battalion of the 14th Regiment, which occupied this town, was relieved by a Battalion of the 30th Regiment, belonging to the Third Corps (THIELEMANN's). PIRCH had just put his Corps in motion, with a view to cross the Dyle by the town of Wavre, when the approach of the Enemy was announced. The Defile was crowded with the troops; the progress of their march could not be otherwise than slow; and at this moment Lieutenant Colonel SOHR, whose Brigade formed the Rear Guard of the Corps, sent in word, that the Enemy presented a force of six Regiments of Cavalry, ten pieces of Artillery, and two strong Columns of Infantry. The Wood of Sarats, close to the Farm of Auzel, was now occupied by some Battalions of the Eighth Brigade, the command of which had devolved upon Colonel RECKOW. PIRCH placed the whole of the Rear Guard under the Orders of General BRAUSE, the Commander of the Seventh Brigade, and reinforced Lieutenant Colonel SOHR with the 11th Hussars and four pieces of Horse Artillery. BRAUSE posted the remaining Battalions of the Eighth Brigade in rear of the Wood, and the three Regiments of Cavalry on the right, with the Foot Battery No. 12 in their front. The Seventh Brigade, deployed into line, remained in reserve. Lieutenant Colonel LEDEBUR retired slowly before the Enemy, and formed a junction with the Eighth Brigade, under Colonel RECKOW; who maintained his position until three o'clock in the afternoon, against the Advanced Guard of VANDAMME's Corps. Between three and four o'clock, General BRAUSE ordered the retreat. Lieutenant Colonel SOHR crossed the Bridge at the Mill of Bierge, which was occupied by two Companies of the 2nd Battalion of the 14th Regiment; and then followed the Reserve Cavalry of PIRCH's Corps, to which his Brigade belonged, but which he did not overtake until he reached the Field of Waterloo. The Enemy did not advance with much vigour; the retreat was conducted with perfect order, and the Fusilier Battalion of the 1st Pomeranian Landwehr, under Major KRÜGER, distinguished itself on the occasion. After the passage of the river had been effected, the 1st Battalion of the Elbe Landwehr remained at Bierge until the Bridge was destroyed and the Mill set on fire. The 11th Hussars and the 2nd Battalion of the Elbe Landwehr were posted in observation of the passages across the Dyle, and did not rejoin the Corps before the following day.