Brigadier General J. H. Martindale, Military Governor of Washington, for temporary duty. No movement will be made without further orders from these headquarters.

XIV. The Third Brigade, Pennsylvania Reserve Corps, will prepare to report on the 13th instant to Brigadier General J. P. Slough, Military Governor of Alexandria, for temporary duty. No movement will be made without further orders from these headquarters.

By command of Major-General Heintzelman:

C. H. POTTER,

Assistant Adjutant-General.

SUTTON, [April] 11, 1863.

Captain JOSEPH McC. BELL,

Assistant Adjutant-General, Buckhannon:

That scout I informed you of yesterday came in last night, but has no particular information of the rebel movements.

There is no citizen here in whom I can trust. I will send a party of 3 or 4 out to-morrow toward Lewisburg, and dress them in rebel uniforms.

H. F. MAYER,

First Lieutenant, Commanding Detachment.

CAMP NEAR FALMOUTH, VA.,

April 11, 1863.

His Excellency the PRESIDENT OF THE UNITED STATES:

After giving the subject my best reflection, I have concluded that I will have more chance of inflicting a heavier blow upon the enemy by turning his position to my right, and, if practicable, to sever his connections with Richmond with my dragoon force and such light batteries as it may be deemed advisable to send with them. I am apprehensive that he will retire from before me the moment I should succeed in crossing the river, and over the shortest line to Richmond, and thus escape being seriously crippled. I hope that when the cavalry have established themselves on the line between him and Richmond, they will be able to hold him and check his retreat until I can fall on his rear, or, if not that, I will compel him to fall back by the way of Culpeper and Gordonsville, over a longer line than my own, with his supplies cut off. The cavalry will probably cross the river above the Rappahannock Bridge, thence to Colpeper and Gordonsville and across to the Aquia Railroad, somewhere in the vicinity of Hanover Court-House. They will probably have a fight in the vicinity of Culpeper, but not one that should cause them much delay or embarrassment. I have given directions for the cavalry to be in readiness to commence the movement on Monday morning next. While the cavalry are moving, I shall threaten the passage of the river at various points, and, after they have passed well to the enemy's rear, shall endeavor to effect the crossing. I hope, Mr. President, that this plan will receive your approval. It will obviate the necessity of detaching a force from Wash ington in the direction of Warrenton, while I think it will enhance my chances for inflicting a heavy blow upon the enemy's forces.

We have no news from over the river to-day, the enemy refusing to