The consequence of this condition of things is that when it was necessary to leave but a small force for the defense of the city, which the casualties of the service may again at no very distant time render imperative, these lines of defense were absolutely an embarrassment, so great was their extent, and so easily could they be turned on both sides of the river by going through the swamps, which are now perfectly dry and passable for both footmen and artillery.

Now, what I have to propose is that these defenses shall be so arranged as to conform to the real condition of things which has happened and may happen again, that is to say, for a small garrison, a hostile population, and a dry season.

Very considerable progress has already been made in one branch of this work; that is, adapting the defenses to the present state of water. This has been done by cutting down tress and making abatis from the flanks of the parapet to the lakes on either side.

What is most wanted is a citadel, or a place of arms, occupying semi central point which shall overlook the city, render it independent of the presence of a naval force, and which shall at the same time be a rendezvous for the reserves and a safe place of deposit for arms, ammunition, and commissary stores.

The selection of the site of this fortress or citadel will involve a great many considerations, and its construction be attended with some expense.

I therefore respectfully suggest that if the general commanding has not already determined in his own mind where this point should be, that he will either select it himself, or institute a board to make the selection of the site and determine upon the extent and trace of the work, so that the force which we now have employed in strengthening the old rebel lines at the parapet and at the company canal, may be, when their work is done with, which will be in a few days, placed upon this new work.

I have the honor to be, general, very respectfully, your obedient servant,

W. H. EMORY,

Brigadier-General, Commanding.

HEADQUARTERS DEFENSES OF NEW ORLEANS, July 20, 1863.

Major General N. P. BANKS:

GENERAL: Recent events have shown that the establishment of civil power in this State is, I think, premature, and wholly inconsistent with the interest of the United States.

Without for a moment intending to cast a reflection on the probity of those having supervision of the internal commerce, under this system supplies have been put in the La Fourche district which have enabled the enemy, who were in very considerable force, to subsist there for the last month. The supplies captured by them at Brashear were very few, and they have subsisted almost entirely upon the supplies which were sent from this city under the aegis of the civil authority for the use of the plantations. The same has been the case with the plantations below this city on the west bank of the river.

The enemy have drawn supplies from them through the lakes and various little canals tapping this river below this city to a very considerable amount.