Numbers 14. [From the War Department, August 18.] UNITED STATES MILITARY TELEGRAPH.

General POPE:

I fully approve your movement. I hope to push a part of Burnside's forces to near Barnett's Ford by to-morrow night, to assist you in holding that pass. Stand firm on the line till I can help you. Fight hard, and aid will soon come.

H. W. HALLECK,

General-in-Chief.

Numbers 15. HEADQUARTERS ARMY OF VIRGINIA, Rappahannock Station, August 20, 1862-8.30 a. m. (Received 10.30 a. m.)

Major-General HALLECK:

Your dispatch of yesterday received last night. I shall mass my whole force along what is known as Marsh Run, about 2 1/2 or 3 miles northeast of Rappahannock Frod, occupying Kelly's Ford with an advance guard from my left, Rappahannock Ford with an advance guard from the center, and picketing strongly with cavalry the fords above me as far as the road from Sperryville to Warrenton. If the enemy attempt to turn my right by the way of Suphur Springs they will probably march direct on Warrenton, from which place a good turnpike conducts to Washington. Such a movement, however, will expose their flank and rear, and you may be sure I shall not lose the opportunity. My right will be considerably refused along the railroad, as far, at least, as Beatlon Station. What relations with me will the corps of Fitz John Porter have? I should like to know exactly. I am going out to post my command. I have heard from ReNumbers He crossed safely yesterday at Kelly's Ford and Barnett's Ford. The enemy so far has made no movement in advance. I think they are not yet ready, for want of transportation for supplies, to cross the Rapidan.

JNO. POPE,

Major-General.

Numbers 16. [Received August 21, 1862, from the War Department, Washington.] UNITED STATES MILITARY TELEGRAPH.

General POPE:

I have telegraphed General Burnside to know at what hour he can re-enforce ReNumbers Am waiting his answer. Every effort must be made to hold the Rappahannock. Large forces will be in to-morrow.

H. W. HALLECK,

General-in-Chief.

Numbers 17. HEADQUARTERS ARMY OF VIRGINIA, Rappahannock Station, August 21, 1862-7.30 a. m.

Major-General HALLECK:

The enemy has made no farther advance since yesterday afternoon, but his cavalry pickets are in plain view of our front. After full examination of the ground I have determined to maintain the line of