KNOXVILLE, December 17, 1863.

Longstreet has taken the offensive against General Parke, who has fallen back to Blain's Cross-Roads, where Granger is now concentrating his corps. I intend to fight there if Longstreet comes. It is reported that he is re-enforced by a portion of Ewell's corps. Elliott arrived yesterday, and I have ordered him toward Morristown to meet Wheeler's cavalry and operate on Longstreet's flank.

This question of supplies is very serious, and cramps military operations, having to concentrate and call in the foraging parties. It is with great difficulty that I can get quarter rations of meal or flour from day to day. It is very important, therefore, to get boats running on the Tennessee River so as to supply us this winter with bread, small stores, and ammunition.

Beef and hogs can be driven to us. I have sent orders to Captain Dickerson to this effect, but ask that you will also give such orders as will put the thing through.

The boat has just arrived at Loudon with timely supplies, which have been brought up on the train.

Please order medicines and hospital stores to be brought up on the next boat.

J. G. FOSTER,

Major-General.

Major-General GRANT,

Chattanooga.

KNOXVILLE, December 19, 1863. [Received Chattanooga, 21st.]

I have just returned from the front to find your telegrams of the 15th, 16th, and 18th.

Longstreet is near Rutledge with a force equal to my own, but shows no disposition to attack us in our position. Had circumstances been favorable, I intended to attack him, acting in accordance with what I understood to be the wishes of General Halleck, but I am not sure that it would prove a good operation; at any rate, the freshet in the river from the recent rains has delayed operations for some days. I would like to confer with you in order to understand more fully what operations will lead to the best results.

Can I do this by telegraphing from Tazewell, to which place I can go for the purpose, or will it be better to come to Chattanooga by boat?

J. G. FOSTER,

Major-General.

Major-General GRANT.

BLAIN'S CROSS-ROADS, December 19, 1863.

I am here in force. The high water from rains and the state of the roads impeded operations very much. The men are suffering for want of shoes and clothing. Ammunition is also becoming scarce; of some arms entirely expended. Please to send by steamer to Loudon, as soon as possible, 5,000 pairs of shoes, 10,000 pairs socks, 5,000 shirts, 5,000 blouses, 10,000 overcoats, 10,000 shelter