MAYOR'S OFFICE, New York, September 12, 1862.

Honorable EDWIN M. STANTON,

Secretary of War:

SIR: From information received at this office, I have reason to apprehend at any moment the visit to this port of one or more rebel iron-clad war steamers from Europe. To meet the danger, we have only ungarrisoned forts, mounting a less number of guns than is desirable, and not one of them rifled.

I have written to Governor Morgan, requesting that one of our city militia regiments (about 260 strong) be detailed to man the forts. The Governor promises to give the matter immediately attention, and I presume will accede to my suggestion, or otherwise provide for manning the fortifications.

The proper order from your Department to the Governor might expedite matters. I have also conferred with Brigadier General Harvey Brown, commandant in our harbor, on the subject.

I now apply to you for whatever aid you may be able to afford us in the way of strengthening our defenses, especially by sending us, if you can, additional guns, some of them rifled, for the fortifications.

A few experienced gunners also would be very desirable, if not indispensable, to instruct the inexperienced men who will occupy the forts.

I regret to have to trouble you with this matter at the present time when the enemy is in the vicinity of our capital, but he safety of New York is of too much consequence to the Union to allow of your not fully appreciating the propriety of this application.

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

GEORGE OPDYKE,

Mayor.

DEPARTMENT OF STATE, Washington, September 13, 1862.

Mr. ROEST VAN LIMBURG, &c.:

SIR: I have the honor to acknowledge the receipt of your note of the 10th instant, in which, after referring to the restoration of $800,000 in coin to Mr. Amedee Couturie, you request me to cause the other articles seized at his house also to be restored to him, and to state in reply that the Secretary of War will be accordingly asked to give directions in the proper quarter to that effect.

I avail myself of this opportunity to renew to you, sir, the assurance of my high consideration.

WILLIAM H. SEWARD.

WASHINGTON, September 1 General E. D. MORGAN,

Albany:

GENERAL: The Secretary of War directs that a garrison of one company each be placed in Forts Richmond and Schuyler, New York Harbor.

By order of Major-General Halleck:

J. C. KELTON,

Assistant Adjutant-General.