[Inclosure B]

HEADQUARTERS ARMY OF THE POTOMAC,
October 10, 1862-12 p. m.

Captain B. F. FISHER,

Commanding Signal Detachment:

The rebel General Stuart,with about 3,000 cavalry and two batteries took Chambersburg this afternoon, and is now trying to return to Virginia. By daylight to-morrow you will have a party at Williamsport, to communicate with Rowley; one on Washington Monument, to communicate with Spencer, at Hagerstown; one on Catoctin Ridge, west of Frederick, commanding the valleys on both sides for the ridge,and communicating with a point as near as is practicable to this camp. Notify Point of Rocks of the facts. All are to look out and instantly report any force of this nature trying to move across the Potomac Washington Monument reporting to Hagerstown, Rowley reporting to Hagerstown and Williamsport, and stations on Catoctin Ridge reporting near here. Carry out these orders as promptly as possible.

Send a party to assist Rowley and ascertain whether he is taken prisoner, as is possible, the enemy being reported as having crossed at the ford near Fairview. Cox is at Hancock, with his division in railroad cars, and will move by rail the instant he receives information. Officers will return after forty-eight hours, ordered.

By order of Major A. J. Myer:

WM. S. STRYKER,

First Lieutenant and Adjutant, signal Corps.

[INCLOSURE C.]

SIGNAL STATION,

Hagerstown, Md., October 10, 1682-2 p. m.

ALBERT J. MYER,

Signal Officer and Major U. S. Army:

SIR: This morning, soon after break of day, a force of the enemy's cavalry and artillery, of which we saw at least four regiments of cavalry and two pieces of artillery, crossed the Potomac at or near Dam Numbers 4, capturing several of our pickets and several refugees from Virginia. The force then proceeded toward the turnpike leading from Fairview, and crossed it about 1 mile beyond Fairview, and proceeded up a dirt road into a valley called Little Cove.

The first have we knew of their being in our vicinity was a force of about 20 cavalry appearing in sight, about 20 rods from our station. We immediately abandoned the station, those of us that had our horses saddled. We were obliged to leave everything except our side-arms. We proceeded to Clear Spring, and found that Captain Gary, with his cavalry, had fallen back toward Williamsport about 3 miles. He had previously called in all his pickets from along the river and canal. Some of his pickets were forced to retire toward d Hancock. The cavalry and artillery was seen to enter the little Cove above mentioned. From the Little Cove there are two roads, one of which leads toward Hancock, the other, through a gap in the mountain, to the Clear Spring and Mercersburg turnpike.

What their object or intentions maybe is entirely unknown to us. General Cox's division passed Fairview on the road to Hancock between 3 and 5 a. m. He must be aware of the raid, as some of the pickets fell back that way.

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