Give orders that will cause the brigade to be there where the previous instructions indicate by dawn this morning.

Very respectfully, &c.,

[IRVIN MCDOWELL.]

HDQRS. DEPARTMENT NORTHEASTERN VIRGINIA,
Centreville, Va., July 19, 1861.

COLONEL: Learning yesterday there were but few troops of the enemy in this place, I directed Brigadier-General Tyler to take, it, and keep up the impression we were to advance in this direction. I then went to Colonel Heintzelman's division, to make arrangements to turn the enemy's right and intercept his communications with the South. I found on examining the country that the roads were too narrow and crooked for so large a body to move over, and the distance around too great to admit of it with any safety. We would become entangled, and our carriages would block up the way. I was therefore forced to abandon the plan of turning the enemy's right, and to adopt my present one of going around his left, where the country is more open and the roads are broad and good. I gave orders, therefore, for the forces to move forward on the Warrenton turnpike so soon as the supply trains came up and the men could get and prepare their rations.

Whilst with Colonel Heintzelman's division I learned that the advance had become engaged with the enemy. I therefore directed the movement, which in the first instance was to take place after the arrival and distribution of subsistence, to take place at once. By the time I got over from Colonel Heintzelman's column the firing on both sides had ceased. I have directed General Tyler to make a report of the affair, which I will forward when it comes to hand. I learn from the medical director that there were three killed, twenty-one slightly and eight severely wounded; total, thirty-two. Of the severely wounded three have since died.

A negro, belonging, he says, to Colonel Fontaine, of Virginia, came in last night from the other side, saying his master had been killed at the first cannonading. he reports great havoc among the enemy, but his imagination is evidently too active to trust to his statements. All the divisions are now here or in the immediate vicinity. I have ordered General Runyon to station the larger part of the reserve on the railroad to guard it.

I have the honor to be, very respectfully, your most obedient servant,

IRVIN MCDOWELL,

Brigadier-General, Commanding.

Lieutenant Colonel E. D. TOWNSEND,

Asst. Adjt. General, Hdqrs. of the Army, Washington, D. C.

[Inclosure.]

GENERAL ORDERS, HDQRS. DEP'T N. E. VIRGINIA,

Numbers 19.] Fairfax Court-House, July 18, 1861.

The troops will move to-day as follows: Heintzelman's division will go to Little Rocky Run, on the road hence to Centreville. Miles' division will go to Centreville. Tyler's division will go beyond Centreville, on the road to Gainesville. Hunter's division will go as near Centreville as he can get water.

The above movements will be made after supplies shall have been received. If the supply trains do not come up in time, division commanders