To which the following reply was received:

WASHINGTON, August 14, 1862-1.40 a.m.

I have read your dispatch. There is no change of plans. You will send up your troops as rapidly as possible. There is not difficulty in landing them. According to your own accounts, there is now no difficulty in withdrawing your forces. Do so with all possible rapidity.

H. W. HALLECK,

Major-General.

Major General GEORGE B. McCLELLAN.

Before I had time to decipher and reply to this dispatch the telegraph operator in Washington informed me that General Halleck had gone out of the office immediately after writing this dispatch, without leaving any intimation of the fact for me, or waiting for any further information as to the object of my journey across the bay. As there was no possibility of other communication with him at that time I sent the following dispatch, and returned to Harrison's Landing:

CHERRYSTONE INLET, August 14, 1862-1.40 a.m.

Your orders will be obeyed. I return at once. I had hoped to have had a longer and fuller conversation with you after traveling so far for the purpose.

GEO. B. McCLELLAN,

Major-General.

Major General H. W. HALLECK, Washington, D. C.

On the 14th and 15th, and before we had been able to embark all our sick men, two army corps were put in motion toward Fort Monroe. This was reported in the annexed dispatch:

HEADQUARTERS ARMY OF THE POTOMAC,
Berkeley, August 14, 1862-11 p.m.

Movement has commenced by land and water. All sick will be away to-morrow night. Everything being done to carry out your orders. I don't like Jackson's movements. He will suddenly appear when least expected. Will telegraph fully and understandingly in the morning.

GEO. B. McCLELLAN,

Major-General.

Major General H. W. HALLECK, Washington, D. C.

The phrase "movement has commenced," it need not be remarked, referred obviously to the movement of the main army after completing the necessary preliminary movements of the sick, &c. The perversion of the term to which the General-in-Chief saw fit to give currency in a letter to the Secretary of War should have been here rendered impossible by the dispatches which precede this, of the 14th, which show that the movement really began immediately after the receipt of the order of August 4.

The progress made in the movement of the 15th was reported in the following dispatches:

HEADQUARTERS ARMY OF THE POTOMAC,
August 15, 1862-12 m.

Colonel Ingalls this moment reports that after embarking the remaining brigade of McCall's division with the sick, who are constantly accumulating the transports now disposable will be all consumed.

Two of my army corps marched last night and this morning en route for Yorktown-one via Jones' Bridge and the other via Barrett's Ferry, where we have a pontoon bridge. The other corps will be pushed forward as fast as the roads are clear, and I hope before to-morrow morning to have the entire army in motion.

A report has just been received from my pickets that the enemy in force is advancing on us from the Chickahominy,but I do not credit it; shall know soon. Should any more transports arrive here before my departure, and the enemy do not show such