I have written very plainly as I understand the case, and I hope you will give me credit for having fully considered the matter, although I may have arrived at very different conclusions from your own.

Very respectfully, your obedient servant,

H. W. HALLECK,

General-in-Chief.

Major General GEORGE B. McCLELLAN,

Commanding, &c., Berkeley, Va.

On the 7th I received the following telegram:

WASHINGTON, August 7, 1862-10 a.m.

You will immediately report the number of sick sent off since you received my order, the number still to be shipped, and the amount of transportation at your disposal; that is, the number of persons that can be carried on all the vessels which by my order you were authorized to control.

H. W. HALLECK,

Major-General.

Major General GEORGE B. McCLELLAN.

To which I made this reply:

HEADQUARTERS ARMY OF THE POTOMAC,
August 7, 1862-10.40 p.m.

In reply to your dispatch of 10 a.m. to-day I report the number of sick sent off since I received your order as follows: 3,740, including some that are embarked to-night and will leave in the morning. The number still to be shipped is, as nearly as can be ascertained, 5,700.

The embarkation of five batteries of artillery, with their horses, wagons, &c., required most of our available boats, except the ferry-boats. All the transports that can ascend to this place have been ordered up; they will be here to-morrow evening. Colonel Ingalls reports to me that there are no transports now available for cavalry, and will not be for two or three days. As soon as they can be obtained I shall send off the First New York Cavalry.

After the transports with sick and wounded have returned, including some heavy-draught steamers at Fort Monroe that cannot come to this point, we can transport 25,000 men at a time. We have some propellers here, but they are laden with commissary supplies and are not available.

The transports now employed in transporting sick and wounded will carry 12,000 well infantry soldiers. Those at Fort Monroe, and of too heavy draught to come here, will carry 8,000 or 10,000 infantry. Several of the largest steamers have been used for transporting prisoners of war, and have only become available for the sick to-day.

GEO. B. McCLELLAN,

Major-General.

Major General H. W. HALLECK, Commanding U. S. Army.

The report of my chief quartermaster upon the subject is as follows:

HEADQUARTERS ARMY OF THE POTOMAC,
Office of Chief Quartermaster, Harrison's Landing, August 7, 1862.

GENERAL: I have the honor to return the papers herewith which you sent me with the following remarks:

We are embarking five batteries of artillery, with their horses, baggage, &c., which requires the detailing of most of our available boats, except the ferry-boats. The medical department has ten or twelve of our largest transport vessels, which, if disposable, could carry 12,000 men. Besides, there are some heavy-draught steamers at Fort Monroe that cannot come to this point, but which can carry 8,000 or 10,000 infantry.

I have ordered all up here that can ascend to this depot. They will be here to-morrow evening. As it now is, after the details already made, we cannot transport from this place more than 5,000 infantry.

There are no transports now available for cavalry. From and after to-morrow, if the vessels arrive, I could transport 10,000 infantry. In two or three days a regiment of cavalry can be sent if required. If you wait, and ship from Yorktown or Fort Monroe after the sick and wounded transports are at my disposal, we can transport 25,000 at a time. The number that can be transported is contingent on circumstances referred to.