... (Dobson's battalion) Cavalry, and Ewing's battery, he crossed the mountains over icy roads and paths, in the midst of tempests a part of the time, and, on the 16th of December, struck the railway at Salem , on the headwaters of the Roanoke River. There he destroyed the station houses and rolling stock, and a large quantity of Confederate supplies; cut and coiled up the telegraph wires for half a mil...