WASHINGTON, August 15, 1863.

Colonel C. R. LOWEL, Jr.,

Commanding Cavalry:

It is reported to authority which appears reliable that White is in the vicinity of Dranesville with a body of some 350 men. Can you make any expedition in that vicinity with sufficient force to attack if your succeed in finding the party? Captain Means, Independent Rangers, stationed at Point of Rocks, says he knows all the country from Dranesville to Aldie, and wishes to co-operate with you. Let me know when you can start, so that I can communicate with Means and appoint a rendezvous. Name some place at which [you?] can meet him and them.

J. H. TAYLOR,

Chief of Staff.

HEADQUARTERS ARMY OF THE POTOMAC, August 16, 1863-10. 30 a. m.

(Received 11 a. m.)

Major General H. W. HALLECK,
General-in-Chief:

The following regiments will proceed to Alexandria to-day under the command of Brigadier General T. H. Ruger, viz: Second Massachusetts, Third Wisconsin, Twenty-seventh Indiana, Fifth Ohio, Seventh Ohio, Twenty-ninth Ohio, Sixty-sixth Ohio, Fourth Ohio, Fourteenth Indiana, Fifth Michigan, One hundred and twenty-sixth Ohio.

Aggregate strength of these regiments is about 3,800. General Ruger has been directed to report to you by telegraph on arriving at Alexandria, for further instructions,and also by telegraph to the Quartermaster-General for transportation.

The number of men already detached and who have left are as follows: August 14, regulars and Vermont brigade, under General Ayres, 4,000; August 15, regiments, 1,400. *; August 16, Ruger's command, 3,800; making in all 9,200,which, when swollen by convalescents and men detached on extra duty (who will be sent as soon as possible), will make the aggregate force fully up to and over 10,000. I do not propose, without further orders, to send any more. I have sent you my best troops and some of my best officers.

GEO. G. MEADE,

Major-General, Commanding.

HDQRS. ARMY OF THE POTOMAC, August 16, 1863-1 p. m.

(Received 1. 20 p. m.)

Major General H. W. HALLECK,
General-in-Chief:

It appears from later returns that the aggregate strength of the six regiments that left here yesterday for Alexandria was 1,800, instead of 1,400, as stated in my dispatch of this morning. Please correct my statement accordingly.

GEO. G. MEADE,

Major-General.

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*See dispatch following.

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