25th. Two gunboats and Nelson's division have probably reached him by this time. I will send Crittenden's division as soon as a gunboat returns to escort it. Had I not better immediately move General Grant, with cavalry and light artillery, up the Tennessee, and endeavor to destroy the railroad connections at Corinth, Jackson, and Humboldt? I require very little cavalry and light artillery for Pope's expedition. They can be easily spared. I have transports all ready at Paducah.

H. W. HALLECK,

Major-General.

The enemy is mounting additional guns at Columbus and is fortifying Island Numbers 10.

HEADQUARTERS DEPARTMENT OF THE OHIO,
Nashville, Tenn., February 28, 1862.

Mr. A. H. MARKLAND,

Special Mail Agent:

SIR: I am directed by the general commanding to request that you will at once take charge of the post office in this city, and take such means as will open the mails at the earliest possible moment.

Very respectfully,

J. M. WRIGHT,

Assistant Adjutant-General.

QUARTERMASTER-GENERAL'S OFFICE,

Washington City, February 28, 1862.

To the PRESIDENT:

SIR: I have ought much lately upon the results of our experimental gunboats ont he Wastern rivers. They have done even better than I had hoped, and it appears to me that the experience thus far gained may be made available for important operations.

I have a letter from Mr. Theodore Adams, boulder of the Easex and of the mortar boats. I requested him at Cairo to examine the gunboats returned from Fort Donelson, and inquire particularly as to the effect of the fire of the batteries upon the iron plating.

From the newspaper reports and from a letter of Captain Wise, the quartermaster of the Flotilla, and from Mr. Adams' letter, I reached the following conclusions:

The only guns used in these river attacks are the bow buns.

The broadside guns are serviceable as a reserve to replace a disable bow gun, as in case of bursting of a rifle on the Carondelet.

No shot heavier than a 32-pounder ball, except a 64-pounder rifle shell, struck the iron plating of the forward bulkhead, which is inclined at an angle of 45 degrees.

The only effect of the shots which did strike the iron plating was to dent it and glance off without injury.

The 64-pounder rifle shell which wounded Captain Foote and killed a pilot passed through the pilot-house, which it struck at a high angle, and which was sheathed with iron only 1 1/2 inches thick.

The Essex is sheathed on the broadside with 3/4 inch iron only, on heavy timber. Keeping brown on to the battery, the shot which struck