U. S. STEAMER PENSACOLA,

New Orleans, La., February 15, 1864.

Major General N. P. BANKS,

Commanding Department of the Gulf:

GENERAL: I have received your communication of this date, and have the honor to inform you in reply that the Arizona was ordered to this place by Admiral Farragut before his departure. I propose to send three gun-boats to Berwick Bay, which, together with the one already there, will make up the number required for the contemplated movement. I shall use all possible dispatch to have them there by the 1st March.

Very respectfully, your obedient servant,

JAS. S. PALMER,

Commodore, Commanding at New Orleans.

PORT HUDSON, LA., February 15, 1864.

Major D. C. HOUSTON,

Chief of Engineers, Department of the Gulf:

SIR: In compliance with your order I have visited Plaquemine and have examined the works in course of construction at that point. I respectfully submit the following report: The plan of the work shows a bastioned square (300 feet polygon side), axis nearly perpendicular to the river. The two bastions toward the field salient the levee which closes the gorge. The flanking arrangement is defective; the collateral faces being nearly in line, the flanks cannot sufficiently protect the sector deprived of fie in the prolongation of the capitals. The parapet is pretty well constructed (interior crest 9 feet, exterior about 8 feet, perpendicular between crests 9 feet).

The above-mentioned defect cannot be remained now. I then drew the attention of the commanding officer to the following points: The interior slope should be steeper and rivetted (it is now at least one-half); the inclination of the superior slope should be increased in order to have the crest of counterscarp under fire (the line of fire passes now over 3 feet above that crest); a small traverse should be constructed in rear of sally-port; the platforms, a powder magazine, and store-room should at once be constructed. The parapet is nearly completed.

After consultation with the commanding officer, who shows much intelligence and zeal, I propose the following armament:

First, in every salient, one barbette, at least 24-pounder, four guns; second, in every shoulder except one, one heavy barbette, five guns; nine heavy guns.

In there of the curtains, platforms for one field gun; in every flank, one embrasure for field gun; in traverse, one embrasure for field gun.

Reduced armament: In every salient, one heavy barbette gun, the rest of the platforms arranged for field pieces, of which four should be 12-pounders. In this case from six to eight field guns would assure a fair defense.

The site of the fort is so chosen that it can not only not defend the city, but the defense of the work will even necessitate the destruction of the city (the city lies northwest of fort and between this and bayou); but considering that the town has no military importance