retire from there, and it is important that the movement should take place speedily. Nothing should go forward, therefore, on the railroad without the sanction of the commanding general, and all that can be brought in must be brought in rapidly. As to Major Haller's command, it should retire before the rear of the army leaves Fairfax, and so at each station it should retire before the last of the troops pass the station. The command should be brought in on the cars. The general wishes no risk to Major Haller's command on account of the stores. The latter should of course rather be sacrificed than the command. How many prisoners remain at Fairfax Station? The general wishes an examination made of the entire railroad as far as Falls Church, in case he should wish to throw supplies out there. When Major Haller's command reaches Alexandria it is to proceed to Washington, encamping on Fourteenth street near the college. Please so inform the major, and tell him to report his arrival to General William or General Marcy.

S. WILLIAMS,

Assistant Adjutant-General.

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HEADQUARTERS,
Washington, September 2, 1862-6 p. M.

Captain C. B. FERGUSON,

Assistant Quartermaster, Alexandria:

Please convey to the commanding officer Eighth Illinois Cavalry the directions of the general commanding that all the cavalry of that regiment is to report to Brigadier General J. D. Cox at Upton's Hill as fast as it arrives. Keep the general commanding advised of the arrival of these troops, and of their departure to join General Cox under these orders. All of General Pleasonton's command of cavalry (other than the Eighth Illinois, above ordered to be posted) as fast as it arrives is to be sent to join Pleasonton at his camp between Forts Runyon and Albany. No other orders must be given by any other authority to interfere with the speedy and the immediate execution of this order. Convey General McClellan's orders to Major Francis N. Clarke, chief of artillery of Sumner's corps, to move his four batteries to the vicinity of Arlington and encamp there in such position as that they can be moved to any point. Convey instructions to Colonel Wainwright to move to move his five batteries to the same place with same orders. Convey orders to Taft's battery to move at once and report to General Abercrombie at the Chain Bridge. Also convey orders to Lieutenant-Colonel Getty to move his three batteries to the north side of the Potomac and encamp them somewhere on Fourteenth street a little out of the city, but convenient to the reached, and whence they can be ordered to any point. Any other of Getty's batteries may join him that may arrive after this dispatch. The remaining batteries are to remain at Alexandria ready for movement at an instant's notice. Do you know where Colonel Robert Williams' Massachusetts cavalry is? If so, tell him to report here instantly. Please acknowledge.

JAS. A. HARDIE,

Lieutenant-Colonel, Aide-de-Camp, and Actg. Asst. Adjt. General

[12.]