WASHINGTON, October 8, 1864-11.30 a.m.

Major-General WALLACE,

Baltimore, Md.:

It is reported that Mosby, with about 800 men, has come through Snicker's Gap, and as the guards have been removed from the Potomac to guard the Manassas railroad, he may cross the river and make a raid into Maryland. Send all your available mounted force toward Rockwill to guard Washington Branch, and also look out sharp for Baltimore and Ohio Railroad.

H. W. HALLECK,

Major-General and Chief of Staff.

BALTIMORE, MD., October 8, 1864-1 p.m.

(Received 3 p.m.)

Major-General HALLECK:

Your telegram just received. General Tyler is ordered to execute it at once.

SAML. B. LAWRENCE,

Assistant Adjutant-General.

(The general commanding being absent.)

WASHINGTON, October 8, 1864.

Major-General WALLACE,

Baltimore, Md.:

As Mosby has four pieces of artillery, it will be well to send a battery your cavalry. Inform your men that Mosby rides in a buggy on account of wounds, and may thus be recognized.

H. W. HALLECK,

Major-General and Chief of Staff.

BALTIMORE, MD., October 8, 1864-2.30 p.m.

(Received 3.40 p.m.)

Major-General HALLECK,

Chief of Staff:

Your telegram received. General Tyler has been ordered to send four pieces of artillery, with all the available cavalry he has, which will not be over 200 men, to Rockville. He has 200 dismounted men of First Delaware Cavalry. Requisition was made for horses a month ago, and not heard from yet. The quartermaster here has no horses, or would furnish them at once.

SAML. B. LAWRENCE,

Assistant Adjutant-General.

(The general commanding being absent.)

BALTIMORE, MD., October 8, 1864-4 p.m.

(Received 5 p.m.)

Major General H. W. HALLECK,

Chief of Staff:

General Tyler reports that all the available cavalry was sent last night to vicinity of Rockville. Smith's cavalry was to push down through Sandy Spring and drive the guerrillas upon Colonel Knight, who would