No. 9. Report of Captain Charles L. Davis, Chief Signal Officer.

HDQRS. ARMY OF THE POTOMAC, SIGNAL DEPARTMENT, April 22, 1865.

COLONEL: In compliance with paragraph 9 of Special Orders, No. 94, headquarters Army of the Potomac, April 14, 1865, I have the honor to submit the following report of operations of the signal corps of this army from the 29th ultimo to the 9th instant:

During this period the disposition of the corps was as follows: One officer and from seven to ten men with each army corps, one officer and forty men with the depot camp, five officers and sixty men with the reserve party, and two officers and seven men with these headquarters. The parties with army corps had general instructions to make themselves and their men on the flanks and front of the corps to which they were attached, to gather for the corps commander such information, by means of telescopic observations, as they were able to obtain of the movements of the enemy; also to be ever watchful for opportunities to open communication by signals with these headquarters, especially when such communication would be important; they were also instructed to make themselves useful as aides-de-camp, when the nature of the country or the movements of the troops prevented the performance of their legitimate duties. The reserve detachment was at all times, weather and movements of the troops favoring, distributed along the front and flanks of the army, with the same general instructions. A small portion of this detachment, however, was always kept in hand for the purpose of opening any lines of signal communication or establishing any station of observation that the occasion might require.

At the date of the commencement of this campaign {March 29] the stations occupied by the reserve party in front of Petersburg were almost identically those occupied during the past winter, viz:

No. 1, at the Walthall house, on the road leading from the City Point Railroad to Point of Rocks, and bearing north 45 east from the central part of Petersburg. This station commanded a view of parts of the city of Petersburg, portions of country south and southeast of Petersburg, points on the Richmond and Petersburg road north of Pocahontas, a point on same road near Port Walthall Junction, and three of the enemy's signal stations on the left bank of the Appomattox River, and all signals used on the enemy's stations were intercepted and interpreted.

No. 2, on a hickory tree, on a knoll of ground near the Gibbon or Friend house, bearing north 70 east from the central part of Petersburg, commanding a partial view of the city, the military roads on the northeast and northwest slopes of Cemetery Hill, a road leading north from Pocahontas, and the enemy's batteries on left bank of the Appomattox.

No. 3, at the Avery house, commanding a plain view of the enemy's lines of works on the east slope of Cemetery Hill from the crater to the lead-works, a road running north from Pocahontas [same as seen from No. 2], a point on the Cox road a short distance west of the city, and a point on the South Side Railroad three miles west of the city.

No. 4, on a pine tree, in Fort Davis, commanding a view of the enemy's works from the Jerusalem plank road to the Halifax road, and a clear view of the roads in the vicinity of the lead-works.