Simultaneous Orders were consequently despatched by eleven o'clock for the march of PIRCH's Corps from Namur upon Sombref, and of THIELEMANN's Corps from Ciney to Namur. An Order had already, in the course of the day, been forwarded to BÜLOW at Liege, desiring him to make such a disposition of his _Corps d'Armée_ as should admit of its concentration at Hannut in one march; and at midnight a further Order was despatched, requiring him to concentrate his troops in cantonment about Hannut. ZIETEN was directed to await the advance of the Enemy in his position upon the Sambre; and, in the event of his being attacked by superior numbers, and compelled to retire, to effect his retreat as slowly as circumstances would permit, in the direction of Fleurus, so as to afford sufficient time for the concentration of the other three Corps in rear of the latter point. The vigilance which was thus exercised along both the Anglo-Allied and Prussian line of Outposts, obtained for WELLINGTON and BLÜCHER the fullest extent of information which they could reasonably have calculated on receiving respecting the dispositions of the Enemy immediately previous to an attack. They had been put in possession of the fact that considerable masses of French troops had moved by their right, and assembled in front of Charleroi. Still, this baring of the frontier beyond Tournai, Mons, and Binche, of the troops which had previously occupied that line, and their concentration in front of Charleroi, might be designed to mask the real line of operation, to draw the Anglo-Allied troops towards Charleroi, upon which a feigned attack would be made, while the real attack was intended to be by Mons. Hence no alteration was made by the Duke in the disposition of his forces; but the Prussian Field Marshal immediately ordered the concentration of his own troops at a point where they would be at hand in case Charleroi should be the real line of attack, and whence they could far more readily move to the support of WELLINGTON, should that attack be made by the Mons road. * * * * * ZIETEN's position, and his line of Advanced Posts, have already been described. His Right Brigade (the First), having its Head Quarters at Fontaine l'Evêque, held the ground between Binche and the Sambre; his Centre Brigade (the Second) lay along the Sambre, occupying Marchienne au Pont, Dampremy, La Roux, Charleroi, Châtelet, and Gilly; a portion of his Third Brigade occupied Farciennes and Tamines on the Sambre, while the remainder was posted in reserve between Fleurus and the Sambre; and his Left Brigade (the Fourth) was extended along this river nearly as far as Namur. The Reserve Cavalry of the First Corps had been brought more in advance, and was now cantoned in the vicinity of the Piéton, having Gosselies for its point of concentration. In this position, ZIETEN, without making the slightest alteration, remained fully prepared for the expected attack on the morrow.