to run the trains by schedule, and the telegraph, although valuable as an auxiliary, should not be used as a principal. It is desirable that uniformity should be iintroduced in the management of all railroads used for military purposes.

Very respectfully submitted.

H. HAUPT,

Brigadier-General, Chief of Construction and

Transportation, U. S. Military Railroads.

[19.]

SPECIAL ORDERS,
HDQRS. DEFENSES OF WASHINGTON, Numbers 18.
September 27, 1862.

* * * * * *

9. All the cavalry south of the Potomac is placed under the orders of Brigadier General George D. Bayard, and will at once report accordingly. General Bayard will organize the cavalry into brigades and will take immediate measures to bring it as rapidly as possible into a state of efficiency. He will assign to the different corps and independent commanders south of the Potomac such force for orderly service as General Heintzelman may deem necessary for that purpose.

* * * * * *

By command of Major-General Banks:

RICHD. B. IRWIN,
Captain, Aide-de-Camp, and Acting Assistant Adjutant-General.

[19.]

HEADQUARTERS ARMY OF THE POTOMAC,
September 28, 1862--8 p. m.

General A. PLEASONTON,

Commanding Cavalry:

GENERAL: Reports from several different sources, received at these headquarters during yesterday and to-day, induce the belief that the main rebel army is moving from the vicinity of Martinsburg toward Winchester. To gain more positive information upon this subject, the commanding general directs that you at daylight to-morrow morning take a force of about 1,500 cavalry and two batteries of horse artillery and, crossing at the ford in front of General Porter's position, proceed in the direction of Martinsburg as far as practicable without incurring great risk to your command. Should you meet with no force of the enemy sufficient to stop you this side of Martinsburg, and you find that the rebels have retreated, you will follow tem until you come up with their rear, doing them all the damage in your power, by capturing stragglers, trains, artillery, &c. Please inform General Porter when you cross the Potomac, so that he may have his artillery placed in position and ready to cover your crossing if it should be necessary.

R. B. MARCY,

Chief of Staff.

[19.]

SPECIAL ORDERS,
HEADQUARTERS NINTH ARMY CORPS, Numbers 8.
Mouth of Antietam Creek, Md., September 28, 1862.

The following officers and enlisted men of this command have been honorably mentioned in the official reports of the engagement on the 17th instant, and their names are hereby published as a testimony to