Court-House, by the road leading down the James River, will not only be the terminus of the latter line, but also that from Prince George Court-House. Below this crossing the stream is represented to be impassable, no road crossing it, or at least can be made so by slashing the dense undergrowth which borders it. Lieutenant Lydecker accompanied me also in this reconnaissance, and, in order to be certain as to the selection of the most suitable site for a field-work to unite the lines above referred to, I directed him to superintend the felling of such timber in the neighborhood as might conceal from the same point of view the direction of the respective lines, and also ordered some detailed surveys to be made. These works were not quite completed to-day. When finished, Company B, U. S. Engineers, is already on the ground ready to commence the construction of the work determined upon. The two remaining officers of the U. S. Corps of engineers, with their respective companies, have been engaged as follows: Captain Gillespie, in immediate charge of the line on front of the Tenth Corps, extending from the Appomattox to the Norfolk railroad, reports the completion during the week of Fort McGilvery, and the partial construction of a new line of infantry parapet to the right and left of it. He has also partly inclosed Battery (lunette) Numbers 8 and Battery Numbers 14 by strong parapets.

In explanation, I would here beg leave to state that I have directed a few batteries along the line to be closed, so as to be at least partially self-protected in case the defense of the line should be left to the field-works and certain contiguous batteries. The service of the latter could not be judiciously dispensed with in connection with the proper defense of the former. In addition to the operations above referred to, Captain Gillespie has also had a fraise constructed above referred to, Captain Gillespie has also had a fraise constructed in front of the line from Fort Stedman to Battery Numbers 11, and one from Fort Haskell to Battery Numbers 13. One is also formed around Fort McGilvery. The revetment in Battery Numbers 5 has been replaced magazines for mortars built in Fort Haskell and Battery Numbers 11, and a large bomb-proof constructed in Fort Stedman. The battalion of First New York Volunteer Engineers directed the working details. Lieutenant W. H. H. Benyaurd has been during the week in the immediate charge of certain alterations, repairs, and additions along the Second Corps front, extending from the Norfolk railroad to Fort Alexander Hays. The terre-plain and ditches of Fort Davis have been drained, some of the old magazines filled, and new ones constructed; also new embrasures pierced and platforms laid for additional guns. This work is badly located in reference to the present line, and should have been farther advanced on higher ground. It was selected and planned, I believe, in reference to the refused line from the Jerusalem plank road back toward the Blackwater Swamp. A magazine and bomb-proof have also been completed in Fort Rice. Some of the embrasures and part of the parapet of Fort Sedgwick having been considerably damaged on the 22nd by some very excellent artillery practice on the part of the enemy's batteries, Lieutenant Benyaurd was directed to superintend the repairs. The parapet is being newly rivetted and strengthened and will be finished to-morrow. The embrasures will be attended to to-morrow night. The present system of sharpshooting along that front prevents any work of that kind being done during the day. A new line has also been staked out by him, connecting Fort Sedgwick and Battery Numbers 22, and the latter with Fort Davis. A requisition for working details to construct it will be made to-morrow. Company A, U. S. Engineers, was detailed to report to Lieutenant Beyaurd. In compliance with my previous instructions,