The estimated force requisite for all these purposes, based on the assumption that rebel capacity for local mischief in these regions should what we now have, would be:

For the Cumberland column-Three regiments of infantry, one regiment of cavalry, and one battery of artillery.

For Cheat Pass--One regiment of infantry.

For Kanawha--One regiment of infantry and one battery of artillery.

For Big Sandy--One regiment of infantry.

Total--Six regiments of infantry, one regiment of cavalry, and two field batteries, the most important of which are the three regiments of infantry and one of cavalry at Cumberland. They should be sent there without delay. Should they be ordered from an adjoining State, time could be gained by sending forward all troops on the railroad except those strictly requisite to guard the railroad line and the depots. Should the rebel forces east of the Blue Ridge fall back towards Lynchburg, retaining their organization and force, as now seems possible, I would advise strengthening the Lewisburg column so as to make and effective force of from 12,000 to 15,000 men, with orders to seize the Southwestern Virginia and Tennessee Railroad, and make a strong demonstration on Lynchburg, seizing it if opportunity offers. On this supposition an additional force of 6,000 or 8,00 men should be thrown into the great valley, to occupy August and Rockbridge and watch the passes through the Blue Ridge there and southward.

Very respectfully, your obedient servant,

W. S. ROSECRANS,

Brigadier-General, U. S. Army.

HEADQUARTERS, Baltimore, March 12, 1862.

Honorable E. M. STANTON,
Secretary of War:

SIR: I would suggest that the police force of this city be transferred at once to the police commissioners recently appointed by the Legislature of this State, with the exception of the provost-marshal and some 10 policemen, without waiting for the appropriation asked for, and referred to in your letter of the 10th instant. The city authorities can then provide for the payment of the remaining 440 officers and men, and the United States be relieved from all responsibility in regard to them.

I am, very respectfully, your obedient servant,

JOHN A. DIX,

Major-General.

CHARLESTOWN, March 13, 1862.

Brigadier General R. B. MARCY,

Chief of Staff:

General Hamilton occupied Winchester this morning at 7 o'clock. The rebel force left the town at 5 o'clock yesterday. The cavalry of the enemy left but an hour in advance of our forces. The railway and telegraph will be put in immediate operation between Harper's Ferry and Winchester.

N. P. BANKS,

Major-General, Commanding.