was sent to open a station at Fort Lincoln, so that with Sergeant Richards at Fort Sumner and Captain Dillingham at Fort Reno the line was complete from the Potomac to the Eastern Branch. On the 12th Lieuts. F. S. Benson and E. H. Wardwell reported from Baltimore, and were placed in charge of the stations at Forts Slocum and De Russy, which were in charge of Sergeant Kintner and Corporal Wallace. During the 10th, 11th, and 12th the officers were continually engaged in sending messages of an important character. On the 14th Colonel Haskin applied for an officer to be placed at Fort Marcy, Va. ; accordingly Corporal Wallace was taken from Fort De Russy and ordered to Fort Marcy. On the 16th, by request of Major-General Doubleday, General Augur directed me to send an officer to Fort Baker, D. C. I accordingly sent Lieutenant Benson from Fort Slocum, and Lieutenant Strong was ordered from Fort Totten to Fort Slocum, the latter fort being farthest in advance and more important. On the 20th Lieutenant Strong was ordered to Fort Reno and Captain Dillingham to Fort Slocum. This change was thought proper, as Lieutenant Strong had recruiting papers at Signal camp that needed his attention. On the 21st Captain Russell and Lieutenant A. T. Abbott were directed to resume their duties at Signal Camp, the exigency having passed, and their services were not needed in the field as much as in camp.

The officers and men were prompt in the discharge of their duties, and I take pleasure in recommending to your notice Lieutenant Asa T. Abbott, whose station was continually under the enemy's fire, and who many times narrowly escaped being struck by the enemy's bullets, but maintained his position and continued to work his station, under fire, for nearly two days.

* * * * * *

The health of the detachment is very good.

I am, very respectfully, your obedient servant,

WM. R. ROE,

Captain and Chief Signal Officer, Dept. of Washington.

FREDERICK, MD., August 1, 1864--6. 30 a. m.

(Received 8. 15 a. m.)

Major General H. W. HALLECK,

Chief of Staff:

From the best information I can obtain the enemy's force north of the Potomac is only a cavalry force, one portion of it raiding east and the other west, trying to divert our attention from the Shenandoah Valley. It was reported to me last night that his eastern detachment was at Littlestown, Pa., some fifteen miles south of Gettysburg, and I have ordered General Duffie to follow, and attack him with his cavalry wherever found. I presume he will try and return by Jeb Stuart's old route. The heat is so intense and the dust so deep that our infantry is suffering dreadfully. Six fell dead yesterday in one of our smallest brigades, and others are suffering in proportion. It appears impossible for the officers of the Sixth and Nineteenth Corps to keep their men up. So many are suffering from sunstroke, and all from the intense heat and constant marching, that I fear, unless they have some rest, they will be rendered very inefficient for any service.

D. HUNTER,

Major-General.