ALEXANDRIA, August 28, 1862-10.30 a. M.

Major-General BURNSIDE,

Falmouth:

Rebel cavalry at Leesburg yesterday p. M. Jackson in direction of Middleburg. Have nothing from Popr or the front to-day. Give me state of affairs with you. Rebel cavalry are between you and Alexandria. Can you communicate with Pope or Porter? If so, do so and inform me result. Am anxious. I am very badly off for cavalry and artillery. Answer.

GEO. B. McCLELLAN,

Major-General.

[12.]

AUGUST 28, 1862-1.05 p. M.

General WHIPPLE,

Arlington:

What garrison and guns in Fort Buffalo? I think it ought to be strongly occupied, and that any disposable cavalry should watch Vienna and Falls Church. Make the best arrangement you can as to Falls Church and please reply at once in regard to Fort Buffalo.

GEO. B. McCLELLAN,

Major-General.

[12.]

HEADQUARTERS ARMY OF VIRGINIA,
Bristoe Station, August 28, 1862-5 a. M.

Major General FITZ JOHN PORTER,

Commanding Fifth Corps:

GENERAL: Major-General Pope directs me to say that General Hooker reports his ammunition exhauted. General Pope desires, therefore, that you come forward with your command at once with all possible spped, and that you send back to hurry up your ammunition train.

I am, general, your obedient servant, very respectfully,

GEORGE D. RUGGLES,

Colonel and Chief of Staff.

[12.]

HDQRS. THIRD ARMY CORPS, ARMY OF VIRGINIA,
August 28, 1862.

Colonel A. N. DUFFIE,

First Rhode Island Cavalry:

The general commanding is disappointed at not hearing anything from you. If you do not see any enemy, the general wishes you to repair to the front, where your regiment can be of service. Report by return messenger without fail.

Very respectfully, your obedient servant,

ED. SCHRIVER,

Colonel and Chief of Staff.

[12.]

HARPER'S FERRY, August 28, 1862.

Major-General WOOL,

Baltimore, Md.:

Reports from my scouts and information from citizens confirm me in the belief that rebel cavalry has largely increased in number to-day at