Coolidge or Surgeon McParlin. The commanding officer of the infantry will report, if possible, this evening to one of the medical officers above mentioned.

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

GEO. D. RUGGLES,

Colonel and Chief of Staff.

[12.]

HEADQUARTERS,
Harper's Ferry, August 31, 1862.

Colonel B. F. DAVIS,

Commanding Eighth New York Cavalry, Harper's Ferry, Va.:

The colonel commanding the brigade directs you take post at Summit Point, on the Winchester railroad, with your regiment, it being a point where supplies from this place can more readily reach you and the nearest to the scene of operations where your services are most required, viz, Berryville, Winchester, Snicker's Ferry, and the ferries on the Shenandoah generally. The Twelfth Virginia (rebel) Cavalry has its headquarters at Middletown, seven miles from Winchester, where it has been recruited from a skeleton to a regiment of seven companies of about sixty strong each. A strong picket of this regiment is kept at Berryville and Snicker's Ferry, and a camp east of the Shenandoah at Round Mountain. It will be your first duty to closely watch the operations of this active partisan corps, which has all the advantage of you in fleeter horses, light equipments, and knowledge of the by-roads are Captains Rouss and White. The former burned the train of cars not over a mile from your station; the latter, captured in Loudoun County, at Waterford, part of Captain Means' company of rangers. White has his camp at or near Round Mound. His business seems to be to take horses and cattle to supply the rebel army. It would be very desirable to break up his command, communications, and business. From information received by telegraph it is almost certain Jackson's army has been broken and defeated. His line of retreat is cut off in almost every direction except by Snicker's Ferry. A sharp lookout in that direction except by Snicker's Ferry. A sharp lookout in that direction will give you the opportunity of picking up stragglers and perhaps capturing a flying battery. If Winchester is attacked, General White, its commander, will fire four guns, with an interval of two minutes. Push up a light scout instantly in that direction to watch and ascertain the cause, sending to these headquarters an express immediately on the first alarm and the result of the observation of the scout; so soon as the alarm is given cars will be sent up to bring the companies at Wadesville back to Charlestown and their baggage, and to bring yours to this place.

If the force of the enemy is strong you will operate in its front or flank, preserving your communication with this place, on which you will fall back, if not cut off; in that case you will retreat on Martinsburg, cross at Shepherdstown, and join my forces down the left flank of the Potomac. I shall order four companies of the Twelfth Illinois Cavalry now at Martinsburg to take post at Smithfield, six miles north of you, with orders to communicate with you, and Captain Cole's with Means' cavalry (four companies) to operate in Loudoun County from Hillsborough, Leesburg, to Snicker's Ferry. Warn your troops of these corps, that a mistake may not be made and you fire into each other. The general order from War Department allows you while in Virginia to