NASHVILLE, TENN., October 23, 1864.

Lieutenant-Colonel CLARK, A. A. G., Army of the Tennessee:

COLONEL: In compliance with orders I beg leave to report that, upon my arrival here on the 25th ultimo, I consulted with Brigadier General R. W. Johnson, chief of cavalry, Military DIVISION of the Mississippi, as to the best means of procuring horses for our cavalry, and at his suggestion proceeds to Saint Louis for the purpose of consulting with Colonel Merrill, in charge of horses at that place. I was informed by the colonel that our cavalry at Memphis had been furnished with 6,008 horses within six weeks, that the Government had no horses on hand at that time, and that he had not doubt that the command was fully supplied. I then proceeded to Memphis, found the command organized into two DIVISIONS, the first under Brigadier-General Hatch, absent in Western Tennessee with Major-General Washburn; the other under Colonel Winslow, absent in Arkansas and Missouri; General Grierson remaining in Memphis as chief of the cavalry corps as organized by Major-General Washburn. The two DIVISIONS number some 6,000 or 7,000 effective men, fully armed and equipped. Knowing that I could accomplish nothing in sending to the front the DIVISION under General Hatch as contemplated in my letter of instructions, and having no communication by mail or otherwise from Memphis with either of the DIVISION commanders, I concluded to proceed to this place and report the state of affairs and avail myself of the proffered leave of absence had in view when I departed from department headquarters. Upon my arrival here I learned at General Thomas' headquarters that Major-General Washburn would be here within the next twenty-four hours. I concluded to have an interview with him and read my letter of instructions to him, having failed to meet the general at Memphis. I saw the general last night and was informed that General Hatch was at Clifton with his command, and that he did not see how Hatch could be sent to the front until the return of the DIVISION under Winslow in Missouri. The general seems loath to part with any of the cavalry, and wishes to retain them on the Mississippi. I beg leave to differ with the general. The DIVISION under General Grierson, including the brigade at Vicksburg, concentrated at Memphis, will be ample for all purposes. If concentrated at that point they will be enabled to make forays into the enemy's country, and by their movements either compel Forrest to abandon his present stamping ground or cope with a force that will preclude the possibility of his again making a successful raid into that city. I have been unable to reach you by telegraph and have, therefore, received a leave of absence for twenty days from headquarters DIVISION of the Mississippi, and will report from this place upon its expiration.

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

JOSEPH F. KNIPE,

Brigadier General, U. S. Vols., Chief of Cavalry, Army of the Tenn.

WASHINGTON, October 23, 1864 - 5 p. m.

Major-General THOMAS:

I received information to-day, having great appearance of authenticity, that there is to be a rebel raid into Western Kentucky; that it is to consist of 4,000 infantry and 3,000 cavalry, and is to start from Corinth, Miss., on the 4th day of November.

A. LINCOLN.

Send copy to General Washburn at Memphis.

A. L.