After our retreat from Norfolk and falling back upon this place I was ordered to report to the honorable Secretary of War for further orders by Major General Benjamin Huger. I reported accordingly, and received verbal orders from the honorable Secretary of War to establish communication on the James River and Appomattox, which I have accordingly done, as follows: One post at Drewry's Bluff, communicating with Chaffin's Bluff, thence down the river the Gregory's farm, where there is a good view of the river for 15 miles. I found it impossible to get communication lower in consequence of the sinuous character of the river. The posts on the Appomattox are from Rhea's farm, on the western side of the Appomattox, to Blanfield, on the eastern side of the river; thence to Cobb's farm, between Point of Rocks and Port Walthall, on the western side of the river; thence to Clifton, on the same side of the river, at the obstructions, amid the fortifications covering them; thence to Old Blanford Church, near Petersburg; from thence to McIlwain's building, on Sycamore street, near the custom-house, the headquarters in Petersburg; making in all six stations between the mouth of the Appomattox and headquarters.

I have each post doubled, in order to transmit messages with the least possible delay. I can get communication with Rhea's farm, the lower post on the Appomattox, to headquarters, a distance of 15 miles, and pass through six posts, in twenty minutes. The river is exceedingly hard to communicate by, in consequence of its sinuous character and dense timber upon its banks.

On the 26th ultimo the posts at Rhea's farm, Blanfield, and Cobb's were shelled out by a fleet of gunboats, which ascended the river rather suddenly, but which returned on the 27th, after burning one of their vessels, which had grounded in the Appomattox channel.

The discipline of the corps is good, and the men drilled by sight and sound. All are sworn into secrecy, and apply themselves to their duty with commendable zeal. The men not being armed, I would most respectfully recommend to the honorable Secretary of War to arm them with army revolvers or light carbines, that they may have some means of protecting themselves in case of a sudden attack.

In addition to the men who are stationed at the several posts herein mentioned I keep a reserve at the Halfway Station, on the Richmond and Petersburg Railroad, with a complete outfit for any emergency or demand that circumstances may require. I have a complete and good outfit for fifteen posts, in addition to an outfit send to Major Alexander for twelve posts.

I have the honor to be, with great respect, your obedient servant,

J. F. MILLIGAN,

Captain and Signal Officer, Department of the Appomattox.

[Indorsements.]

JULY 7, 1862.

Respectfully referred to Colonel Gorgas to know if the arms asked for on the third page of this letter can be conveniently supplied.

S. COOPER,

Adjutant and Inspector General.

JULY 10, 1862.

Respectfully returned. No pistols or carbines on hand. Shot-guns may be supplied perhaps.

J. GORGAS,

Chief of Ordnance.