[Inclosure.]

FROM LOUDON.-Dr. Abernathy, surgeon of the post at Loudon, arrived in town last night, and reports that a party of three of Byrd's men had been sen near that place, and that on Saturday night a party of citizens attempted to capture them, but did not succeed. They succeeded, however, in getting their guns, bayonets, &c., which they threw away, after firing on the attacking party, to facilitate their flight. The citizens returned the fire, but "nobody was hurt on either side." The Lincolnites told a supposed friend that they were off no detailed duty, to be ready to burn bridges, &c., as soon as the grand Union Army makes its appearance in East Tennessee, which they say Colonel Byrd assured them it would surely do, 50,000 strong, in two weeks at furthest, and he bade them tell the Unionists here "to be of good cheer, and take the oath as often as required of them." They also state that their party consists of 100 men. Our military authorities would do well to look to this matter.

BOWLING GREEN, December 25, 1861.

Honorable J. P. BENJAMIN,

Secretary of War:

Let nothing prevent Floyd's brigade from coming here immediately.

A. S. JOHNSTON.

HEADQUARTERS WESTERN DEPARTMENT, Bowling Green, Ky., December 25, 1861.

Honorable J. P. BENJAMIN,
Secretary of War C. S.:

SIR: The recent movements of the enemy and the concentration of heavy masses of troops indicated an early advance, and the weather, which has been unusually fine, resembling the fall rather than winter, rendered it probable that a battle would be fought in this vicinity.

Information from various sources shows that every effort has been made by General Buell to concentrate all his strength for a movement upon Tennessee through Central Kentucky, and that not less than 75,000 men are assembled in front of me, while I have not more than 17,000 men for active operations. After a careful examination I have found the line of the Barron River the only good defensible one between Green River and Nashville. Bowling Green from its topography is naturally a strong position, and gives command over Central Kentucky south of Green River, and has easy communication by railroad to Clarksville and by rail and turnpike to Nashville. Its local advantages for defense are good, though requiring a large force for that purpose, as it is situated in an amphitheater of some extent. The place has been strengthened by good defensive work, requiring about 4,000 men for their defense and to be supported by a large force. I have as a further precaution ordered entrenchments to be thrown up under the direction of the chief engineer, Major Gilmer, at Nashville. These arrangements are such that they perhaps double the efficiency of my force for the defense of this line.

The enemy have recently reconstructed the bridges between Louisville and Green River, and have thrown forward a strong advance to