HEADQUARTERS CAVALRY RESERVE BRIGADE,
October 19, 1863-2.15 p. m.

COLONEL: My command has arrived at Catlett's Station. The enemy has retired rapidly on our advance, but not in very strong force, as seen by my advance. Prisoners and citizens report the rear of the rebel infantry went by here this morning. The railroad is destroyed to this place from Bristoe, but not so effectually in this neighborhood as near Bristoe. Here the ties are not burned not the rails bent. My command is out of rations and forage to-night. A reconnaissance just returned from Brentsville reports the enemy about 250 strong there this morning. They went toward Thoroughfare Gap. I have heard cannonading in my right rear to-day. No other news.

Very respectfully,

W. MERRITT,

Brigadier-General, Commanding.

Colonel C. ROSS SMITH,

Headquarters Cavalry Corps, Army of Potomac.

HEADQUARTERS CAVALRY RESERVE BRIGADE,
Near Bristoe Station, Va., October 23, 1863.

CAPTAIN: Inclosed I forward report of casualties since the Reserve Brigade re-entered the field from the Cavalry Depot, near Washington City. The brigade was not with the army during the retrograde movement from the Rapidan, but joined it near Bristoe Station about the 13th instant, after marching from Washington.

From Bristoe Station it marched to Sudley's Springs, thence to Centreville on 15th instant. On the 16th instant, a reconnaissance was made to Bull Run creek; thence on the 17th to Manassas Junction, and on the 18th instant pushed on to Bristoe, where the enemy was found in considerable force and two batteries of artillery.

On the 19th, the command moved on to Catlett's Station, where it remained until the next day, when it returned by order to Bristoe to protect the repair of the railroad, and cover the country to Bull Run railroad bridge. I am still engaged in that duty.

During this time regimental commanders report the loss of 3 men killed, 5 men wounded, and 1 missing; 2 horses rendered unserviceable in action, and 15 broken down on the march.

Since arriving in camp, I have sent to the Quartermaster's Department, Washington City, according to order, 471 disabled, unserviceable horses. There are at least 100 more in the command. This leaves the entire strength for duty not more than 1,500.

The frightful loss among horses is owing to a disease which resembles tetter (called in the army "hoof-rot"), from the effects of which the finest appearing horses in the command become disabled in one day's march. How far this will extend it is impossible to say. The disease seems to have been contracted int he quartermaster's corrals in Washington.

I am, very respectfully, your obedient servant,

W. MERRITT,

Brigadier-General of Volunteers, Commanding.

Captain C. C. SUYDAM,

Assistant Adjutant-General.

23 R-VOL XXIX, PT I