Unless he can escape by passes leading to the north to-night he must be captured. I desire you to move forward at 1 o'clock to-night, even if you can carry with you no more than 2,000 men, though I trust you will carry the larger part of your division. Pursue the turnpike from Centreville to Warrenton. The enemy is not more than 3 1\2 miles from you. Seize any of the people of the town to guide you. Advance cautiously and drive in the enemy's pickets to-night, and at early dawn attack him vigorously. Hooker shall be close behind you. Extend your right well in the attack. Be sure to march not later than 1 with all the men you can take.

JNO. POPE,

Major-General, Commanding.

Numbers 66. HEADQUARTERS ARMY OF VIRGINIA, Near Bull Run, August 28, 1862-10 p.. m.

Major-General HEINTZELMAN:

GENERAL: General McDowell has intercepted the retract of the enemy. Sigel is immediately on his right, and I see no possibility of his escape. I have instructed Kearny to push forward cautiously at 1 o'clock to-night until he drives in the pickets of the enemy, and to assault him vigorously at daylight in the morning. It is of the last importance that Hooker shall march at 3 o'clock to-night, taking the turnpike from Centreville to Warrenton, and resting on that road 1 1\2 miles beyond Centreville, as a reserve for Kearny. Send a copy of this dispatch to Hooker immediately; and I beg you particularly to see that Hooker marches at the time specified, even if he should have to do so with one-half of his men. I shall rely upon this.

JNO. POPE,

Major-General, Commanding.

Numbers 67. HEADQUARTERS ARMY OF VIRGINIA, Near Bull Run, August 29, 1862-3 a. m.

Major-General PORTER:

GENERAL: McDowell has intercepted the retreat of Jackson. Sigel is immediately on the right of McDowell. Kearny and Hooker march to attack the enemy's rear at early down.

Major-General Pope directs you to move upon Centreville at the first dawn of day with your whole command, leaving your trains to follow. It is very important that you should be here at a very early hour in the morning. A severe engagement is likely to take place, and your presence is necessary.

I am, general, very respectfully, your obedient servant,

GEO. D. RUGGLES,

Colonel and Chief of Staff.

Numbers 68. HEADQUARTERS ARMY OF VIRGINIA, Near Bull Run, August 29, 1862-5 a. m.

Major-General RENO:

I sent you verbal orders by Colonel Smith last night. News from the front makes it necessary to modify them. You will accordingly