WASHINGTON, D. C., October 14, 1862.

Major General GEORGE B. McCLELLAN, Commanding, &c..:

GENERAL: I have caused the matters complained of in your telegrams of the 11th and 12th to be investigated. I am now informed by the Quartermaster-General that every requisition from you for shoes and clothing had been filled and the articles forwarded as directed; that all requisitions for tents and blankets had been filled so far as the stock on hand here could furnish supplies, and that the deficiency was ordered to be immediately made up from Philadelphia an New York. There has been no delay that was not unavoidable.

In regard to horses, you say that the present rate of supply is only 150 per week for the entire army here and in front of Washington. I find from the records that the issues for the last six weeks have been 8,754, making an average per week of 1,459. I inclose a copy of a letter of the Quartermaster-General, in answer to my inquiry on this subject.

It is also reported to me that the number of animals with your army in the field is about 31,000. It is believed that your present proportion of cavalry and of animals is much larger than that of any other of our armies.

Very respectfully, your obedient servant,

H. W. HALLECK,

General-in-Chief.

[Inclosure.]

OCTOBER 14, 1862.

Major General H. X. HALLECK,

Commander-in-Chief, Hdqrs. of the Army, Washington, D. C.:

GENERAL: I find that in the month of September there were issued from this department to the army defending Washington, under command of Major-General McClellan, 4,493 horses; from 1st to 11th October, 3,261 horses; total from this department, 7,754 horses. Colonel Ingalls, by special authority from this department, purchased in Harrisburg 1,000 horses, which were taken direct to the army near Frederick and Sharpsburg, so that for six weeks the issue has been at the rate of 1,459 per week.

There remained on hand, on the 11th, 497 serviceable horses, which, with what have daily received since, have been issued before this time.

During the first days of September 1,500 horses, not included in the above, were sent out toward Centreville to the army of General Pope; 41 of these were lost, and the remainder exchanged for unserviceable stock not included in the above statement.

There have been issued, therefore, to the army about the Potomac, since the battles in front of Washington, to replace losses, 9,254 horses. For transportation, a very large number of mules has been supplied in addition to the above.

Is there an instance on record of such a drain and destruction of horses in a country not a desert?

I was informed by Colonel Ingalls, whose report, though called for, has not yet been received, that the number of animals with the army on the Upper Potomac was over 31,000.

I am, respectfully, your servant,

M. C. MEIGS,

Quartermaster-General.