In order to afford greater security to the Right Flank of the Anglo-Allied Army, and also to keep open the communication with the detached forces near Hal, and at Tubize, namely, the Corps of Prince FREDERICK of Orange, and the Sixth British and Sixth Hanoverian Brigades, under Lieutenant General Sir CHARLES COLVILLE; it was deemed essential to occupy the small town of Braine l'Alleud, about three quarters of a mile westward of Merbe Braine: and whence a road leads to Tubize, which is distant between eight and nine miles. With this view, the Third Division of the Netherlands, commanded by Lieutenant General Baron CHASSÉ, was placed under the orders of General Lord HILL; a part of whose Corps, as previously explained, formed the extreme Right of the Anglo-Allied position. The First Brigade, under Colonel DITMERS, occupied the town itself. It consisted of the 35th Battalion of Belgian Light Infantry, the 2nd Battalion of the Dutch Line, and of the 4th, 6th, 17th, and 19th Battalions of Dutch Militia. The 17th Battalion, detached a little to the left, kept up the communication with CLINTON's British Division. The Second Brigade, under Major General D'AUBREMÉ, occupied a good position about half a mile in advance of Braine l'Alleud, upon a height on which stood the Farm of Vieux Foriez. * * * * * It was at a very early hour of the 18th, that Lieutenant Colonel TORRENS, Deputy Quartermaster General, reached Braine le Comte, and delivered to Sir CHARLES COLVILLE the Order (see page 285), for his falling back upon Hal. That General immediately put in motion his two Brigades. These consisted of the Sixth British Brigade, under Major General JOHNSTONE, and the Sixth Hanoverian Brigade, under Major General Sir JAMES LYON, accompanied by Major BROME's British Foot Battery. The remaining Brigade (the Fourth British, under Colonel MITCHELL), as also the other Foot Battery, belonging to the Fourth Division (Captain RETTBERG's Hanoverian), were on the Field of Waterloo. On reaching Tubize, COLVILLE fell in with the Advance of Prince FREDERICK's Corps: and as that was the point of junction with the road leading by Braine le Château and Braine l'Alleud to the position in front of Waterloo; he halted there, and despatched Lieutenant Colonel WOODFORD, Assistant Quartermaster General to the Division, to report his proceedings to the Duke. His Grace expressed himself perfectly satisfied; and desired Lieutenant Colonel WOODFORD to remain upon the Field of Waterloo, in order that he might be prepared to return to Sir CHARLES COLVILLE with any instructions which circumstances might induce the Duke to transmit to him. * * * * * The Artillery of the Anglo-Allied Army, commanded by Colonel Sir GEORGE WOOD, was distributed in the following manner:--