Abstract from the returns of the Department of Northeastern Virginia, commanded by Brigadier-General McDowell, U. S. A., for July 16 and 17, 1861.

Present.

For duty.

Commands. Officers. Men.

General staff. 19 ...

First (Tyler's) Division.* 569 12,226

Second (Hunter's) Division. 121 2,364

Third (Heintzelman's) Division. 382 8,680

Fourth (Runyon's) Division.+ 247 5,201

Fifth (Miles') Division.+ 289 5,884

Twenty-first New York Volunteers. 37 684

Twenty-fifth New York Militia. 39 519

Second United States Cavalry, 4 56

Company E.

Total. 1,707 35,614

Present.

Commands. Total. Aggregate.

General staff. ... 21

First (Tyler's) Division.* 9,494 9,936

Second (Hunter's) Division. 2,525 2,648

Third (Heintzelman's) Division. 9,385 9,777

Fourth (Runyon's) Division.+ 5,502 5,752

Fifth (Miles') Division.+ 5,917 6,207

Twenty-first New York Volunteers. 707 745

Twenty-fifth New York Militia. 534 573

Second United States Cavalry, 63 73

Company E.

Total. 34,127 35,732

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*The total and aggregate present in the Fourth Brigade of this division is not carried out on the original return. hence the anomaly of a smaller total and aggregate "Present" then "Present for duty" in the division.

+See notes 4 and 5, report Numbers 5, post.

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Numbers 2. Report of Colonel Orlando B. Willcox, First Michigan Infantry, of skirmish at Fairfax Court-House.

HEADQUARTERS SECOND BRIGADE, THIRD DIVISION,
Fairfax Station, July 17, 1861.

SIR: After leaving the Old Fairfax road this noon with my brigade, we ;proceeded with an advance guard in skirmishing order and pioneers with axes, and felt our way until the skirmishers came upon this point. The enemy fled precipitately without firing a shot, but we succeeded in capturing a sergeant, a corporal, and nine men, belonging to the First Alabama Rifle Regiment. They occupied two camps, and are reported to have been two regiments, of about 1,000 men each, from Alabama and Louisiana. We found every evidence of hasty departure-provisions; fires burning; a box of medical instruments, partly consumed; a secession flag, &c., in their camps. Our most extended skirmishers towards the left saw also some cavalry scattering and flying.

The enemy must have been early apprised of our coming, but whether their main body had left before we commenced cutting the road I cannot tell. The earthworks were, as supposed, near the railroad. There was a masked earthwork in the woods farther about a mile west of the station, but no guns in any of them. I await the colonel's further orders at this point, having promptly returned after following the Fairfax road two and a half miles and communicating with Colonel Miles.

Very respectfully,

O. B. WILLCOX,

Colonel, Commanding Second Brigade.

Captain C. MCKEEVER,

Assistant Adjutant-General, Third Division.