may lead to an engagement, and everything must be done with a view to this result.

The three following things will not be pardonable in any commander: 1st. To come upon a battery of breastwork without a knowledge of its position. 2nd. To be surprised. 3rd To fall back. Advance guards, with vedettes well in front and flankers and vigilance,w ill guard against the first and second.

The columns are so strong and well provided that, though they may be for a time checked, they should not be overthrown. Each is provided with entrenching tools and axes, and if the country affords facilities for obstructing our march, it also give equal facilities for sustaining ourselves in any position we obtain. A brigade should sustain itself as long as possible before asking for help from another. It can hardly be necessary to attack a battery in front; in most cases it may be turned. Commanders are enjoined to so conduct their march as to keep their men well closed up. This is of great importance. No man will be allowed to get into an ambulance or baggage wagon without written authority from the regimental surgeon or his superior. Guards will be placed over the ambulances and wagons to enforce this order.

Troops will march without their tents, and wagons will only be taken with them for ammunition, the medical department, and for entrenching tools. A small baggage train for each brigade, to take the camp-kettles, mess-pans, and mess kits, and the smallest allowance of personal baggage of the officers and men, will follow at a day's interval the First Division from Fort Corcoran and Vienna. A second subsistence train will follow the Second Division at a day's interval. A wagon for forage will be taken with each battery and squadron. A herd of beef cattle will be sent with each subsistence train. There is on many of our regiments nothing to distinguish them from those of the enemy, and great care must be taken to avoid firing into each other.

The national color must be kept continually displayed, and, if possible, small national colors should be places on the cannon of the batteries.

Division commanders will see that the axmen and engineers at the head of the columns (and men of the ordnance guard) are well provided and in condition to work efficiently. When there are no ax-slings, the axes will be carried and the muskets will be slung.

Department headquarters will be with the Second Division, on the Little River turnpike. Division commanders will communicate with them by every opportunity.

By command of Brigadier-General McDowell:

JAMES B. FRY, A. A. G.

FAIRFAX COURT-HOUSE, July 17, 1861.

Lieutenant Colonel E. D. TOWNSEND,

Asst. Adjt. General, Hdqrs. of the Army, Washington:

We have occupied Fairfax Court-House, and driven the enemy towards Centreville and Manassas. We have an officer had three men slightly wounded. The enemy's flight was so precipitate that he left in our hands a quantity of flour fresh beef, entrenching tools, hospital furniture, and baggage. I endeavored to pursue beyond Centreville, but the men were too much exhausted to do so.

Most respectfully, your obedient servant,

IRVIN MCDOWELL,

Brigadier-General.

20 R R-VOL II