Black Horse and Little Fork Rangers. Some of Mosby's men told him that about 5,000 men were coming down the valley. General Lee's Army of Northern Virginia numbers about 45,000 men, including force now in valley. The army is now better clothed than ever before. Large quantities of clothing and boots have been received from England. I know that Mosby is in Loundon with Hampton's Legion. The man is intelligent. Shall I send him to you?

J. C. SULLIVAN,

Brigadier-General.

CUMBERLAND, January 3, 1864 - 10 a. m.

Brigadier-General AVERELL,

Martinsburg:

I cannot believe it is the intention of Early to attack you in force. If, however, I should be mistaken, and he approach you in large force, you will retire with all the force at Martinsburg to Harper's Ferry, under the protection of our batteries on Maryland Heights, and where we can unite all of our forces and take the offensive. As for Imboden, Gilmor, Rosser, or Fitzhugh Lee, or even all combined, I have no fear but what you can with your command take care of yourself and them too.

B. F. KELLEY,

Brigadier-General.

CUMBERLAND, January 3, 1864 - 10 p. m.

Brigadier-General AVERELL,

Martinsburg:

Imboden and McNeill attacked and captured a wagon train to-day near Williamsport. I presume the movement of troops down the valley to cover this operation and to secure their safe return. I unfortunately have not cavalry sufficient to follow them, and I presume it will be impossible for you to cut them off.

B. F. KELLEY,

Brigadier-General.

CUMBERLAND, January 3, 1864 - 11 p. m.

Brigadier-General AVERELL,

Martinsburg:

Colonel Boyd reports from Winchester at 4 p. m. to-day that Lee's and Rosser's cavalry had gone to Paw Paw, and would probably come to Cumberland; that Early was at Middletown, and was expecting a force from Meade to cross at Front Royal. The Eighteenth Cavalry and White's battalion were left to watch our movements, and were at or near Kernstown. Boyd was going out to meet him. Just received a dispatch from Colonel Mulligan, advising me that Lee and Rosser were besieging Thoburn at Petersburg. Move forward to-morrow morning all of your available cavalry force to Winchester, and assist Boyd. I fear Thoburn is in a tight place.

B. F. KELLEY,

Brigadier-General.