The Passaic grounded far in advance, and at some distance from aid.

And I regret to say that it was entirely due to Mr. Nye refusing to go in her as pilot. Some persuasion was used, but without effect. He was resolute in his reason.

When the vessel was known to be afloat, so much delay occurred, the other monitors being still at some distance, that too little of the night was left, and I reluctantly had to postpone the operation.

I just have your telegram stating that the fire of Wagner is heavy and likely to dismount your guns. You ask me to prevent this, which, of course, I will be glad to do.

It should be understood, however, that this course is likely to expend the force of the iron-clads so much as to render other active operations on my part impossible, so that I shall not be able to operate after Sumter and Wagner are reduced, because the guns will be worn out and become dangerous, the men broken down by day and night work, and the armor much battered.

The Ironsides is a powerful but most impracticable vessel; her great draught prevents approach to the main objects; at the same time her ports only allow of elevation of 4 to 4 1/2. Then her ends are not armored, and between Wagner, Sumter, and Moultrie, she is always enfiladed by one or more of them.

There are seven monitors; of these, one must guard the enemy's iron-clad at Warsaw, another is under repair at Port Royal. Of the five here, one has a gun disabled leaving only four fully available.

Every time they go into an operation the capacity of the guns in them to fire is expended, and probably one-half of this has gone already.

The fire of Sumter is of no account; but most of the guns have been sent to Moultrie, and I cannot get near to one without equally approaching the other, so that there is no diminution of the fire that was encountered in April, but a great decrease on our side, for DuPont had all seven monitors, while I have but four in full order.

I desire now to begin directly on Sumter, but cannot do so if the iron-clads are to be otherwise employed.

So that it remains to choose between this, as well as further operations toward Charleston when Sumter falls, or to expend power daily on Wagner.

Will it not be well, therefore, for us to agree definitely which choice shall be made? For after Sumter is taken, further progress will be arrested if the monitors are used up, either in armament or otherwise.

I am, very respectfully, your obedient servant,

JNO. A. DAHLGREN,

Rear-Admiral, Commanding South Atlantic Blockading Squadron.

MORRIS ISLAND, August 23, 1863.

Admiral DAHLGREN:

What did you ascertain as to the condition of Sumter?

GILLMORE,

General.