SANDY HOOK, September 14, 1861-4 p. m.

Captain ROBERT WILLIAMS, Assistant Adjutant-General:

SIR: The threatening attitude of the rebels upon this portion of my line has induced me to remain here to-day.

The report now is that 3,000 infantry and Captain Ashby's command of cavalry will visit Harper's Ferry this evening. I do not place much confidence in the story; it comes from the town itself.

A messenger from Captain John W. Wilson, commanding near Sharpsburg, stating that his camp is being attacked by a large force, consisting of infantry, cavalry, and artillery, supposed to be about 600, asking aid from me. The cannonading is still going on from the rebel side, but thus far has produced no casualties on our side. As soon as scouts now out return I will decide upon the matter of his request.

For sake of prompt communication along my extended front, I have agreed to permit Mr. Smith, master of transportation on the Baltimore and Ohio Railroad, to reconstruct that portion of the telegraph line which was destroyed by Colonel Donnelly's order at Berlin, and to place an office here, under the supervision of Major Gould, with the understanding that if we are at any time attacked by an overwhelming force the line and office should be destroyed. As a consideration for this permission, Mr. Smith proposes to keep a train of cars and an engine to transport my troops without delay to any point to defend against sudden attack. This seems to me to be [an] admirable arrangement, and I trust it will meet the approbation of General Banks.

Lieutenant-General De Korponay is in command of my camp at Point of Rocks, and he informs me that everything is quiet upon all parts of my command below.

Major Burbank, of the Twelfth Massachusetts Regiment, was here to-day. He informed me that he was ordered to monocacy Aqueduct with two companies, and wanted to know where he should be provisioned from. I told him if he had orders to report to me I would furnish him from Point of Rocks, but if he was that quarter. He requested me to communicate my general instructions to him, which I did, and stated to him if he was ordered to report to me I would give them to him in writing.

Another excellent 6-pounder (iron cannon) has been brought over from Virginia to-day, and will be mounted here for the defense of this point.

Considerable skirmishing is occasionally going on across the river between our pickets, 1 or 2 miles above, and several of the enemy have been killed and wounded; some horses also killed.

Rest assured a perfect defense of the line will be made.

With high regard,

JNO. W. GEARY,

Colonel Twenty-eighth Regiment Pa. Vols., Commanding Post.

HEADQUARTERS HOOKER'S BRIGADE,
Camp Union, Md., September 14, 1861-7 a. m.

Colonel ROBERT COWDIN, Commanding,&c., near Patuxent:

COLONEL: I am directed by the brigadier-general commanding to inform you that he received late last evening from the headquarters of