HARPER'S FERRY, September 25, 1864.

Hon E. M. STANTON,

Secretary of War, Washington, D. C.:

SIR: Availing myself of your permission I present for your consideration my views upon the depot to be established from which to supply the command of Major-General Sheridan. Economy in transportation and certainly in delivery are unquestionably controlling considerations. Martinsburg seems to be ten selected depot. One serious objection to that point is to be found in the fact that there are not sufficient sidings or buildings for the transaction of the Government business necessary to be done in the event of its adoption. In addition, it is on the main track of the Baltimore and Ohio Railroad with its immense business; there will be constant detections arising from the number of trains daily passing over the road and from want of necessary switches and turnouts. Its accessibility and indefensibility render it an unsafe depot in case of disaster; past experience settles that . On the line of the Baltimore and Ohio Railroad, Martinsburg is unquestionably the best selection, but should the depot be on the road? I think not. Winchester or Stephenson's Depot should be the designated spot. To make such selection requires the immediate relaying of the railroad track on the Winchester road to Stephenson's Deport. The distance is twenty-one miles from the present laid track at Halltwon; to Winchester three miles farther. From both places the rock roads of the Valley can be used. there is the best of road-beds, with but one bridge, as I am informed, requiring an eighty-foot trestle, mile and a half per day, so that in twenty days Winchester can be reached by rail.

The advantages: Harper's Ferry, with its ample store-houses, can be made the main depot; Stephenson's or Winchester, the supply depot. Trains can make the run in an hour and a half; in case of emergency in an hour; reduces hauling in wagons twenty-two miles; saves twenty-four hours in time. Can this road be protected? Easily; a regiment at Charlestown, one at Summit Pont, and one at Opequon trestle, the road is effectually guarded. Occupying Ashby's Gap and Snicker's Gap with a good regiment of infantry at each, a regiment of infantry holding Gregory's Gap and HIllsobrough road, with a small force at Keyes' gap from Harper's Ferry garrison,. distributing at these mountain passes such force as can be formed from the now useless cavalry, First Maryland nd Loudoun County guerrillas are effectually shut out of the Valley, and with their hiding-places thus occupied will soon disappear. The cost of constructing this road will soon be realized in the saving of animals, wagons, and freights, and in the time gained in transportation of supplies and troops to the front. The troops on the Baltimore and Ohio Railroad can at once be withdrawn, for the new points and the actual military force now used in the rear will require to be but little strengthened, if at all.

These suggestions are based upon the idea that the upper Valley is to be the theater of General Sheridan's operations. If, however, Lynchburg is the objective point, my opinion is that there should be no base in this valley. No army of such magnitude relying upon its rear for supplies can be maintained for a great distance than 100 miles without either water or railroad transit.

General Sheridan has demoralized if not dispersed Early's army; he might push forward to Stuanton to complete that work. Returning