FLAG-SHIP MALVERN,

Hampton Roads, Va., July 24, 1864.

Lieutenant General U. S. GRANT,

Commanding U. S. Forces in the Field:

GENERAL: I inclose a copy of a communication received to-day from the Navy Department, relative to the expediency of withdrawing the iron-clads from James River. I request the favor of an early reply, giving your views on the subject.

I have the honor to be, general, very respectfully, yours,

S. P. LEE,

Actg. Rear-Admiral, Commanding N. Atlantic Blockading Squadron.

Please address your reply to me at Beaufort, N. C.

[Inclosure.]

NAVY DEPARTMENT,

Washington, July 22, 1864.

Acting Rear-Admiral S. P. LEE,

Commanding N. Atlantic Blockading Squadron, Hampton Roads:

SIR: You will informs this Department whether any of the iron-clads attached to your command can be withdrawn, having due regard to the exigencies of the public service within the limits of your command; whether they are absolutely essential to the holding possession of James River, or other waters of Virginia; and whether the military forces can maintain their positions in Virginia, assisted and protected by wooden vessels only, in case the iron-clads should be withdrawn, or with the assistance and protection of wooded vessels and a portion of the iron-clads.

Answers to these questions, and such other information bearing upon the subjects of inquiry, as your judgment may dictate, can be furnished at your leisure. The opinion of Lieutenant-General Grant upon the points indicated would be valuable, and the Department would be gratified if you should obtain it.

Very respectfully, &c.,

GIDEON WELLES,

Secretary of the Navy.

HEADQUARTERS ARMY OF THE POTOMAC,
July 24, 1864.

Major J. C. DUANE,

Acting Chief Engineer, Army of the Potomac.

MAJOR: Please give me, with as little delay as practicable, your views on the expediency of an assault on the enemy's works after a successful springing of General Burnside's mine, and particularly your views as to the subsequent operations after carrying the enemy's first line and following up a lodgment on the crater of the mine.

Respectfully, yours,

GEO. G. MEADE,

Major-General, Commanding.