MARTINSBURG, September 11, 1862-7.30 p. M.

Colonel MILES:

As near as I can learn I am being surrounded, and sdhall maek immedaite preparation to move toward you. If the train has not been set, let it come at once. Send out a support to Kearneysville as you proposed. I shall march before daylight. There will be no difficulty in supporting me. What I most want is artillery and infantry. Don't fail me.

JULIUS WHITE.

[19.]

HEADQUARTERS,
Harper's Ferry, September 11, 1862.

Lieutenant-Colonel DOWNEY,

Commanding Third Maryland Infantry:

SIR; Your dash upon the enemy with nineteen cavalry at Boonsborough was hazardous and not called for. The reconnaissance was proper, but with your small force [you should] have kept at a distance and not encountered a larger force than your own. The enemy is scattered between Rohrersville and Boonsborough, foraging I expect. I cannot learn he has any dispostion to advance this way. Should he do so it will be through Solomon's Gap or across the Potomac. If the former and you will soon know it by the report of the heavy battery on Maryland Heights, get your regiment together, except that portion at Opequon bridge, and march by the Shepherdstown road to this place. If the river is crossed at Antietam before you know of the march of the enemy on that point your chance of reaching this place is lost. The command at the Opequon bridge is to hold on to that point and preserve the bridge to the last moment. It is all-important to get here the train to-day from Cumberland and whenthe enemy advances on the bridge or on your force, if your chance of reaching here is jeoparized by his crossing the river, to fall back on Martinsburg and join General White. It is contemplated that the company at Opequon shall do so in any event, as you would not have time to get it when necessary tomarch to this point. I si desirable [and] important that the road should be kept open to-day or until the trains reach here from Cumberland. They will contain important supplies, which we must have. What is desirable to impress on you not to abandon your positions without necessity, and when you do, at that particular time when you can reach this place or Martinsburg with safety. When you have to leave Shepherdstown have the ferry-boats broken up; in fact, I see no great necessity of retaining that post, and you can withdraw the company when you please.

D. S. MILES.

Colonel Second Infantry.

[19.]

HEADQUARTERS THIRD BRIGADE

Maryland Heights, Md., September 11, 1862.

Colonel MILES,

Commanding Division, Harper's Ferry, Va.:

Captain Russell has just returned from the neighborhood of Boonsborough and reports that the enemy's line is twenty miles long, the advance in Williamsport. Union men living near the road told the