Applying these remarks to the whole line, it is probable that two hundred platforms should be made, embrasures cut, &c., for field or siege guns, which (earthwork included), is alone a very considerable work.

If the enemy attack Washington, it will be with a large force and numerous artillery. He will concentrate upon the point of attack a large number of pieces; that the garrison should not be exhausted or driven out by shells, adequate bomb-proof shelter should be provided. This is already done to a great extent, but there are yet probably one-half or one-third of the works where such shelter is needed. This is a heavy and expensive work. To obviate further-or rather, to prevent as much as possible-the concentration of the enemy's artillery, I am placing in secure positions, such as Fort Ellsworth and Fort Alexander, on the heights near Battery Cameron (already constructed and armed with rifled 42-pounders, for the same purpose), 100-pounder Parrott guns, to sweep the ground where such concentrations are most likely and dangerous.

The preservation of these works is another important consideration. The winter acts severely upon these earthen scarps and exterior slopes. Much repair is now needed. It has not yet been made, owing to the pressure of other matters. Perhaps it will be best to revet all the scarps and timber. Presuming that none now doubt the necessity of maintaining an adequate defensive line around Washington, I have thrown together these remarks that the commanding general and the War Department may be letter able to understand the actual condition and the requirements, that the existing defensive line shall be adequate, as well as to explain the considerable works of different kinds I have ordered since my return, and what I propose to order. I am unable to estimate what expenditure will ultimately be made, probably $100,000.

J. G. BARNARD,

Brigadier-General.

[OCTOBER 6, 1862.-For Wright to Cox and Halleck to Wright, see Series I, Vol. XVI, Part II, pp. 579, 580.]

WASHINGTON, D. C., October 7, 1862-12.45 p.m.

Major-General McCLELLAN:

Cox's division must go west at once. Couch's [Peck's] division is at Yorktown and Suffolk. The Manassas Gap road can be repaired in a few days. The Leesburg road is much more injured. Your army can reach the former in less time than would be required to repair the latter. The troops to be sent you will be partly new and partly old-mostly new.

Our scouts report the enemy in force at Mount Jackson, Sperryville, and Warrenton, his artillery and heavy baggage moving to Staunton.

McAlester can be sent in Comstock's place, but must go at once.

The Governor of New York wishes a list of officers, non-commissioned officers, and privates, to fill vacancies. He will also call in a few days for officers to take charge of drafted men, to fill old regiments. Have lists made of those who can be spared for that purpose. General Seymour has leave.

H. W. HALLECK,

General-in-Chief.