I have sent to Colonel Haupt to push out construction and supply trains as soon as possible; General Tyler to furnish the necessary guards.

I have directed General Banks' supply trains to start out to-night at least as far as Annandale, with an escort from General Tyler.

In regard to to-morrow's movements I desire definite instructions, as it is not agreeable to me to be accursed of disobeying orders when I have simply exercised the discretion you committed to me.

GEO. B. McCLELLAN,

Major-General.

Major-General HALLECK, Washington, D. C.

On the same evening I sent the following dispatches:

CAMP NEAR ALEXANDRIA,

August 29, 1862-10 p.m.

Not hearing from you, I have sent orders to General Franklin to place himself in communication with General Pope as soon as possible, and at the same time cover the transmit of Pope's supplies. Orders have been given for railway and wagon trains to move to Pope with least possible delay.

I am having inspections made of all the forts around the city by members of my staff, with instructions to give all requisite orders. I inspected Worth and Ward myself this evening; found them in good order. Reports, so far as heard from, are favorable as to condition of works.

GEO. B. McCLELLAN,

Major-General.

Major-General HALLECK, Washington.

CAMP NEAR ALEXANDRIA,

August 29, 1862-10 p.m.

Your dispatch received. Franklin's corps has been ordered to march at 6 o'clock to-morrow morning. Sumner has about 14,000 infantry, without cavalry or artillery, here. Cox's brigade of four regiments is here, with two batteries of artillery. Men of two regiments, much fatigued, came in to-day. Tyler's brigade of three new regiments, but little drilled, is also here. All these troops will be ordered to hold themselves ready to march to-morrow morning, and all except Franklin's to await further orders. If you wish any of them to move toward Manassas please inform me.

Colonel Waagner, Second New York Artillery, has just come in from the front. He reports strong infantry and cavalry force of rebels near Fairfax Court-House. Reports rumors from various sources that Lee and Stuart, with large forces, are at Manassas; that the enemy with 120,000 men intend advancing on the forts near Arlington and Chain Bridge, with a view of attacking Washington and Baltimore.

General Barnard telegraphs me to-night that the length of the line of fortifications on this side of the Potomac requires 2,000 additional artillerymen, and additional troops to defend intervals, according to circumstances. At all events, he says, an old regiment should be added to the force at Chain Bridge, and a few regiments distributed along the lines, to give confidence to our new troops. I agree with him fully, and think our fortifications along the upper part of our line on this side of the river very unsafe with their present garrisons, and the movements of the enemy seem to indicate an attack upon those works.

GEO. B. McCLELLAN,

Major-General.

General H. W. HALLECK,

General-in-Chief U. S. Army, Washington, D. C.

CAMP NEAR ALEXANDRIA,

August 30, 1862-11.30 a.m.

Your telegram of 9 a.m. received. Ever since General Franklin received notice that be was to march from Alexandria he has been endeavoring to get transportation from the quartermaster at Alexandria, but he has uniformly been told that there was none disposable, and his command marched without wagons. After the departure of his corps, he procured twenty wagons to carry some extra ammunition by unloading Banks' supply train.

General Sumner endeavored, by application upon the Quartermaster's Department, to get wagons to carry his reserve ammunition, but without success, and was obliged to march with what he could carry in his cartridge boxes.

I have this morning directed that all my headquarters wagons that are landed be at once loaded with ammunition for Sumner and Franklin, but they will not go far toward supplying the deficiency.

Eighty-five wagons were got together by the quartermasters last night loaded with