Numbers 4. Reports of Captain Orlando M. Poe, Corps of Engineers, U. S. Army, Chief Engineer. HDQRS. MILITARY DIVISION OF THE MISSISSIPPI, CHIEF ENGINEER'S OFFICE, Savannah, Ga., December 26, 1864.

SIR: I have the honor to reporting to the Engineer Department as follows concerning the operations which have just ended in the occupation of Savannah and the opening of complete communications between this army and the forces in the Department of the South:

On the 15th of November the Fifteenth, Seventeenth, and Twentieth Army Corps took up their line of march from Atlanta. Preparatory to the movement, General Sherman directed me to destroy with engineer troops all railroads and property belonging thereto; all store-houses, machine shops, mills, factories, &c., within the lines of the enemy's defenses at Atlanta. The work of destruction was thoroughly done, under my personal supervision, by the Michigan Engineers and Missouri Engineers. About ten miles of track were destroyed by burning the wood-work and twisting each rail, the latter operation being performed by a very simple machine designed by myself. The designed buildings were first burned and the walls afterward razed to the ground. For military purposes the city of Atlanta has ceased to exist, there being no railroad either to or from it. The Chattanooga road was destroyed from Cartersville to Atlanta, the West Point road to Fairburn, and the Macon road to Lovejoy's. On the morning of the 15th of November the march began-the Fifteenth and Seventeenth Corps taking the roads which lead to Griswold and Gordon, on the Macon and Savannah Railroad, and the cavalry moving upon their right flank, threatening Macon; the Twentieth Corps took that passing through Stone Mountain to Social Circle, on the Augusta railroad; the Fourteenth Corps moved on the morning of the 16th of November, taking the road through Lithonia and Covington. The Twentieth Corps destroyed the Augusta railroad from Social Circle to a point near Greensborough, the Fourteenth Corps destroying from Lithonia to Social Circle. The Twentieth Corps then hurried southward through Eatonton to Milledgeville, which place they entered on the evening of the 22nd of November. The Fourteenth Corps deflected at Brick [Store] and passed via Shady Dale, Eatonton Factory, Vaughn's, and Raimoth to Milledgeville, where they arrived early in the morning of the 23rd of November. The Fifteenth and Seventeenth destroyed the Georgia Central Railroad from Griswold to Tennille Station, including the Oconee bridge. The cavalry made a strong demonstration on the works at Macon, and afterward destroyed the railroad from Griswold westward, to include Walnut Creek bridge, three miles east of Macon. The cavalry, supported by Walcutt's brigade, of the Fifteenth Army Corps, had a severe fight at Duncan's farm on the 21st [22d] of November, in which our forces gained a complete victory.

On the 24th of November the Fourteenth and the Twentieth Corps and the cavalry moved from Milledgeville, the cavalry taking the road, via Sylvan Grove, to Waynesborough, intending to pass to the eastward of Millen, and, if possible, liberate the prisoners of war at that point. They struck the Augusta and Millen branch railroad near Waynesborough, captured a train of cars, and burned some track and bridges, but learning that the prisoners had been removed from Millen turned back. The Fourteenth Corps marched direct for Sandersville and the