sending in written reports in advance by mounted messengers, and also notifying the detachment of cavalry at Rockville.

The detachment of cavalry previously stationed at Rockville is ordered to be on the alert, and, on the appearance of the enemy in force, to fall back on the city, sending in written reports in advance. The two regiments guarding the railway from the lines to Annapolis Junction are to be kept in hand, strengthening their guards to-night, and preparing quietly to obey such further orders as may become necessary. To this railway brigade I attached, a few days since, a detachment of cavalry from my escort, for picket and patrol duty. The commanders responsible for the bridges of the Potomac are ordered to strengthen their guards to-night and keep them extra vigilant. The orders of the General-in-Chief in regard to precautions in the way of buckets, &c., in case of fire, have been communicated to them.

General Casey's command, also ordered to be held quietly in readiness to obey any orders that may become necessary, is disposed as follows: Two batteries and three regiments of infantry, with two regiments which have just arrived and are equipped, near Fort Albany; four regiments of infantry on Capitol Hill, and a battery, short of horses, near the Bladensburg toll-gate. I have communicated with General Stoneman, now reporting to General McClellan, from whose telegram, a copy of which has been furnished the General-in-Chief, it will be seen that he is prepared, should the enemy cross, to concentrate his command and fall upon them. I will give such further orders and make such new dispositions as circumstances may require, or the General-in-Chief direct. A staff officer will be at my headquarters during the night.

Very respectfully, your obedient servant,

N. P. BANKS,

Major-General, Commanding.

WASHINGTON, D. C.,

October 15, 1862-10.30 a.m.

Major-General McCLELLAN:

There are additional indications that the enemy is preparing for another raid or a more general movement. The impression is that he will attempt to cross the Potomac below Point of Rocks, in order to cut off your communications and supplies, or to make a dash into Washington. The inactivity of our army encourages these depredations.

H. W. HALLECK,

General-in-Chief.

McCLELLAN'S HEADQUARTERS,

October 15, 1862-8 p.m. (Received 9 p.m.)

Major-General HALLECK:

Your telegram of 10.30 a.m. received. I am guarding the river from Harper's Ferry down to General Stoneman's position, in such a manner that no rebel force can pass without its being known at once. I have given Stoneman orders to keep close watch upon his part of the line. I am using every possible exertion to get this army ready to move. It was only yesterday that a part of our supplies and clothing arrived at Hagerstown. It is being issued to the troops as rapidly as possible.

GEO. B. McCLELLAN,

Major-General.