FLAG-SHIP HARTFORD, Mobile Bay, August 10, 1864. MAJOR: I have the honor to submit, for the information of the major-general commanding the Military Division of West Mississippi, the following report of signal duty performed by the officers of the Signal Corps in the combined land and naval operations against the lower line of defenses of Mobile: My officers were distributed among the principal vessels of the fleet as follows: Captain Denicke, with two flagmen, on the Brooklyn; Lieutenant Dane, with two flagmen, on the Richmond; Lieutenant Adams, with two flagmen, on the Lackawanna; Lieutenant Jerome, with two flagmen, on the Bienville; Lieutenant Kinney and myself, with five flagmen, on the Hartford. Captain Walker, Lieutenant Sizer, and Lieutenant Harris, the latter in charge of the field telegraph, were assigned to duty with Major-General Granger, and operated with the land forces. Lieutenant Denicke remained on board the boat Laura, personally attached to the general commanding. On board each of the lesser vessels of the fleet was placed an instructed man, with one flagman each. This distribution of officers and men was effected on the evening of the 4th. Instructions had been given to those on the fleet to watch for signals from this ship during the operations; and to the officers with the army to open communication from the inside of Dauphin Island with the flag-ship, immediately after we should anchor inside the harbor. The wooden ships of this fleet steamed in column toward the forts, our advance covered by the iron ships, at about 7 a.m. The instructions previously given to the signal officers were faithfully carried out, while opposite the fort (Morgan) exposed to its fire and that of four gun-boats. Several important messages were transmitted from this ship to the Brooklyn, which, having the advance, had stopped under the fire of the fort and gun-boats, delaying the farther progress of the column in the order previously assigned. Captain Denicke, on the Brooklyn, and Lieutenant Kinney, on the flag-ship, received and transmitted these messages with coolness and precision while exposed to the heaviest fire. Shortly after the passage of the forts by the fleet, and while most of the ships were at anchor, the rebel ram Tennessee was seen to be steaming rapidly up the harbor, making directly for the wooden vessels of the fleet. The admiral called upon Lieutenant Kinney and myself to signal the ships to get under way and run down the ram. This message was immediately transmitted to the following ships: the Brooklyn, Richmond, and Lackawanna. The order was promptly obeyed. After the action with the ram, a large number of messages, official, were sent from ship to ship. * * * * * * * * * * At 10 a.m. communication was opened by signals with the army on Dauphin Island, messages were sent from the admiral to the major-general commanding, and answers transmitted. This communication was valuable, and was kept up until after the surrender of Fort Gaines. During the transfer of the troops from Dauphin Island to Mobile Point, preparatory to the investment of Fort Morgan, the services of the officers were constantly in demand. A station was established on Mobile Point, communicating with the navy and with the boat Laura, headquarters of Major-General Granger. This station was equally as valuable as that on Dauphin Island. I have the honor to mention the names of Captain Denicke, acting signal officer, for gallant and meritorious conduct on the occasion of passing the forts, and subsequent close attention to his duties; that of Lieut. J. C. Kinney, acting signal officer, for gallant and meritorious conduct on the same occasion. Lieut. M. C. F. Denicke has displayed energy and attention to duty during the entire recent operations. I recommend that First Lieut. J. C. Kinney and Second Lieut. M. C. F. Denicke, acting signal officers, be ordered to appear before the board for examination of candidates for admission to the Signal Corps of the army. I further respectfully recommend the instructed men on duty in this fleet be ordered to report to the Signal Camp of Instruction, New Orleans. They have not been sufficiently instructed in their duties as to be of service in the field. FRANK W. MARSTON, Major, Signal Corps, U.S. Army, Chief Signal Officer, Military Division of West Mississippi. Major CHRISTENSEN, Asst. Adjt. Gen., Military Division of West Mississippi.