The last reports from the signal-stations yesterday evening were, that the enemy was breaking up his principal encampments, and moving in direction of Culpepper Court-House.
Very respectfully, etc., R.E.LEE, _General_.
These orders indicate General Lee's design--to reach the left flank of the enemy, prevent his retreat by destroying the bridges on the Rappahannock, and bring him to battle in the neighborhood of Culpepper Court-House.

The plan failed in consequence of a delay of two days, which took place in its execution--a delay, attributed at that time, we know not with what justice, to the unnecessarily deliberate movements of the corps commanded by General Longstreet.

This delay enabled the enemy to gain information of the intended movement; and when General Lee advanced on the 20th of August, instead of on the 18th, as he had at first determined to do, it was found that General Pope had broken up his camps, and was in rapid retreat.

Lee followed, and reached the Rappahannock only to find that the Federal army had passed that stream.

General Pope, who had promised to conduct none but offensive operations, and never look to the rear, had thus hastened to interpose the waters of the Rappahannock between himself and his adversary, and, when General Lee approached, he found every crossing of the river heavily defended by the Federal infantry and artillery.
In face of this large force occupying a commanding position on the heights, General Lee made no effort to cross.