There should be an immediate call for all the troops we are likely to require. Second. Washington City, Baltimore, and Harper's Ferry should be designated as schools of instruction, and all troops raised east of the State of Ohio should be sent to one of these three places as fast as raised. Nashville, Decatur, and Stevenson should also be named as schools of instruction, and all troops raised in Ohio and west of it should be sent to those. By doing this, we always have the benefit of our increased force, and they in turn improve more rapidly by contact with veteran troops. To supply Sherman, all the rolling-stock that can possibly be got to him should be sent. An effort ought to be made to transfer a large portion of stores now at Nashville to Chattanooga. This might be facilitated by withdrawing for awhile the rolling-stock from the Nashville and Reynoldsburg Railroad, and a large part of the stock upon the Kentucky roads. There is every indication now, judging from the tone of the Southern press, that, unless Johnston is re-enforced, Atlanta will not be defended. They seem to calculate largely upon driving Sherman out by keeping his lines of communication cut. If he can supply himself once with ordnance and quartermaster's stores, and partially with subsistence, he will find no difficulty in staying until a permanent line can be opened with the south coast. The road from Chattanooga to Atlanta will be much more easily defended than that north of the Tennessee. With the supplies above indicated at Chattanooga, with, say, sixty days' provisions there, I think there will be no doubt but that the country will supply the balance. Sherman will, once in Atlanta, devote himself to collecting the resources of the country. He will take everything the people have, and will then issue from the stores so collected to rich and poor alike. As he will take all their stock, they will have no use for grain further than is necessary for bread. If the enemy do not detach from here against Sherman, they will, in case Atlanta falls, bring most of Johnston's army here with the expectation of driving us out, and then unite against Sherman. They will fail if they attempt this programme. My greatest fear is of their sending troops to Johnston first. Sherman ought to be notified of the possibility of a corps going from here, and should be prepared to take up a good defensive position in case one is sent-one which he could hold against such increase. If Hunter cannot get to Gordonsville and Charlottesville to cut the railroad, he should make all the Valley south of the Baltimore and Ohio Road a desert as high up as possible. I do not mean that houses should be burned, but all provisions and stock should be removed, and the people notified to move out.

U. S. GRANT,

Lieutenant-General.

WASHINGTON, July 15, 1864-12. 30 p. m.

Lieutenant-General GRANT,

City Point, Va.:

Yours of 2 p. m. yesterday just received. Citizens of Maryland, who had intercourse with the enemy in our front, say that rebel officers attributed their retreat to their disappointment in the expected co-operation of General Hill's corps; that they could hear nothing of him and could wait no longer, lest Hunter should come