All the depots, water -tanks, and engines between the Little Cacapon and Cumberland are also destroyed, with the block-houses at the mouth of the South Branch and patterson's Creek . The Chesapeake and Ohio canal, about 2 miles above Old Town, where the embankment is about 40 feet high, has been cut, and General Imboden reports that when he left it the entire embankment, for about 50 yards, had been swept away. A similar crevasse, with like results, was also made in the canal, about 4 miles below Old Town. Lieutenant-Colonel White, of the cavalry, has also cut the Baltimore and Ohio Railroad east of the Point of Rocks. General Milroy has abandoned the south side of the Potomac, occupying Harper's Ferry with a picket, and holds the maryland Heights with about 8, 000 men. General Ewell's corps is north of the Potomac, occupying Sharpsburg, Boonsborough, and Hagerstown . His advance cavalry is at Chambersburg, Pa. The first division of General A. P. Hill's corps will reach this vicinity to-day ; the rest follow. General Longstreet's corps, with Stuart's cavalry, still occupy the Blue Ridge, between the roads leading through Asby's and Snicker's Gaps, holding in check a large force of the enemy, consisting of cavalry, infantry, and artillery . The movement of the main of the enemy is still toward the potomac, but its real destination is not yet discovered . I have though t this a favorable time for General Sam . Jones to advance into Western Virginia, and have so informed him . Should he not be able to accomplish anything more, he will fix the attention of the enemy in that region, and prevent re-enforcements being sent to other points . If any of the brigades that I have left behind for the protection of Richmond can, in your opinion, be spared, I should like them to be sent to me . I am, with great respect, your obedient servant,

R. E. LEE,

General .

His Excellency JEFFERSON DAVIS,

Richmond, Va. -

HEADQUARTERS ARNY OF NORTHERN VIRGINIA . June 23, 1863.

Mr. PRESIDENT: Reports of movements of the enemy east of the Blue Ridge cause me to believe that he is preparing to cross the Potomac. A pontoon bridge is said to be laid at Edwards Ferry, and his army corps that he was advanced to Leesburg and the foot of the mountains, appear to be withdrawing . Their attempts to penetrate the mountains have been successfully repelled by General Stuart with the cavalry . General Stuart last night was within a few miles of Aldie, to which point the enemy had retired. General Ewell's corps is in motion toward the Susquehanna . General A. P. Hill's corps is moving toward the Potomac ; his leading division will reach Shepherdstown to-day . I have withdrawn Longstreet west of the Shenandoah, and, if nothing prevents, he will follow to-morrow . In addition to the supplies that we have been able to gather in Fauquier and Loudoun Counties, in the Shenandoah Valley, and west of the Allegheny, we have collected sufficient north