He had collected together his widely disseminated Brigades, and drawn in his Advanced Posts; an operation which, executed in the darkness of the night, retarded his departure so much that it was two o'clock in the morning before the Reserve Artillery, which formed the head of the Column, struck into the road which at Point du Jour, leads from the Namur _chaussée_ to Gembloux. The Rear Guard of this line of retreat, which consisted of the Ninth Infantry Brigade, under Major General BORCKE, and the Reserve Cavalry, under General HOBE, and was drawn up along the Namur road, having in its front the Fleurus _chaussée_, leading directly towards the Enemy, did not commence its march until after four o'clock, when the sun had risen. The main body of the Corps reached Gembloux at six o'clock in the morning. On approaching this place, THIELEMANN learned that BÜLOW had posted the Fourth Corps about three miles in rear of Gembloux, upon the old Roman road; whereupon Major WEYRACH, Aide de Camp to Prince BLÜCHER, who had continued with THIELEMANN during the night of the 16th, set off to seek out the Field Marshal, and to report to him the position and attendant circumstances of the Third and Fourth _Corps d'Armée_. He soon succeeded in discovering the Prussian Head Quarters at Mélioreux, and communicated the above important information to Count GNEISENAU. THIELEMANN gave his own Corps a halt on the other side of the town, in order that his troops might obtain rest and refreshment. * * * * * The Advance of BÜLOW's Corps had reached Basse Bodecée, upon the old Roman road, at nightfall of the 16th of June. Here that General became acquainted with the loss of the Battle of Ligny: whereupon he ordered the Brigades of his Corps to be posted at intervals along this road, with the exception of the Thirteenth (under Lieutenant General HAKE), which was directed to bivouac more to the rear, near Hottoment, where the same road is intersected by that which conducts from Namur to Louvain. Both Corps remained for some hours in a state of uncertainty as to the direction to be taken for forming a junction with the First and Second Corps. THIELEMANN wrote to BÜLOW that he had received no Orders from Prince BLÜCHER, but that he presumed the retreat was upon St Trond. He also stated that he had not been followed by the Enemy, but that he had heard distant firing on the right, which he concluded was connected with the Duke of WELLINGTON's Army.