COLONEL: I have been informed by Flag Officer Pendergrast that on the 7th instant a battery of three guns was discovered at Gloucester Point, on the York River, nearly opposite Yorktown. One of the small steamers attached to the Home Squadron (the Yankee) exchanged several shots with it yesterday, but as there was one 8-inch gun in the battery and those of the steamer were of much shorter range her commander hauled off.
With regard to the force necessary here, the portions of the surrounding country which should be occupied, and the defenses erected for the protection of the fort, the commanding general and General Totten are much better able to judge than myself. It appears to me, however, that the sand hills, some two thousand yards from the fort, should be occupied and a battery built there. To do this will require a larger force than I have at my disposal. Colonel De Russy suggests that a battery should be erected near the picket bridge, on the Hampton side. In the vicinity is a spring (apparently inexhaustible) of fine water, which may be of the highest importance, though with the present command I entertain no apprehension of a scarcity of water, as, in addition to the supply in the fort, there is a large quantity at the hotel.
The mail-boat from Baltimore was allowed to land the mails here yesterday, and the mail for Norfolk sent there in the steamer William Selden. She has not, however, returned, and I presume has been seized. I inclose herewith a copy of a letter which was yesterday transmitted by mail, and will add that I cannot urge too strongly the necessity of immediately authorizing the repairing of the wharves and of sending the laborers asked for.
J. DIMICK, Col., Comdg.