ninth Indiana, has been ordered to withdraw to a position nearer his infantry supports, somewhere near where General Davis had his headquarters to-day. Instructions were sent you from the general commanding directing that you close in to our right, and this communication will inform you particularly as to the position of our forces. Our headquarters will be at this place to-night, but we will probably strike tents at a very early hour in the morning.

I am, general, very respectfully, your obedient servant,

G. P. THRUSTON,

Assistant Adjutant-General, and Chief of Staff.

7 p.m.

P. S.-Colonel Post's brigade has orders to hold Stevens' Gap at all hazards, as stated within. This dispatch has been delayed by our ignorance of your whereabouts. Colonel Harrison has been given peremptory orders to open communication with you. General McCook is anxious to hear from you as frequently as practicable.

[Indorsement.]

9.45 p.m.

General R. B. MITCHELL:

The within communication was sent you to-day (or ordered sent you) through Colonel Harrison. A copy is now forwarded. In case the others are lost or do not reach you, these will instruct you. General McCook has been anxious to open communication with you all day, and is now much relieved at receiving your courier. General Rosecrans is very particular that complete and speedy communication should be maintained. Several of your staff are here, not having been able to find you to-day. The firing on the left to-day was caused by the enemy making a reconnaissance with a large cavalry force. Sheridan and Davis are here. Their troops encamp to-night between here and Gower's. Colonel Post has had full instructions about holding the gap (Stevens').

Respectfully,

G. P. THRUSTON,

Assistant Adjutant-General, and Chief of Staff.

HEADQUARTERS FOURTEENTH ARMY CORPS,
Crawfish Spring, September 18, 1863-8 p.m.

Major General JAMES S. NEGLEY,

Commanding Second Division:

GENERAL: As soon as possible push down strong pickets along your whole front from the Crawfish Creek, on your left, to your right beyond Matthews' house, or till you connect with the pickets on your right. You will push them well down to the Chickamauga River, as the enemy are reported as lodging their pickets in the woods on our side. Much of the defensible ground is between the road you are on and the river. All the range there is for artillery consists of the clearing which run from the river to the ridge tops. They must be held.

GEO. H. THOMAS,

Major-General, U. S. Volunteers, Commanding.