SAINT LOUIS, January 13, 1862.

Brigadier General SAMUEL R. CURTIS, Commanding, Rolla:

GENERAL: Your telegram of this evening has determined me to order an advance without waiting any longer for advices from Washington. I am quite sick with camp measles, but do not mean to let the public service suffer on that account if I can help it.

Your suggestions about officers in arrest are approved. You are authorized to suspend their arrest and order them into the field. the court-martial will close its proceedings and adjourn sine die. Fletcher's battery will leave here for Rolla Wednesday morning. You now have twenty-four pieces. This will give you thirty. When the Ninth Iowa joins you will have sic more. Dodge's battery will also be sent to Rolla as soon as General Schofield can spare the section now with him. The Forty-third Illinois will be sent to you as soon as they are better armed; also the Second Iowa the moment I can relieve them. Perhaps I may be able to spare two other regiments in course of the week. At any rate, your forces will be superior to any reliable estimate I have received of Price's army. as your advance will necessarily be slow, the additional force will reach you this side of Springfield and will serve as a reserve.

With regard to routes three have been proposed - that by Lebanon, that by Hartville, and a middle road. Colonel Phelps thinks the middle road the best; others say not. You will act from the best information you have there, which is better than I can get here.

Accounts are so contradictory that I am unable to advise you. Lebanon is certainly the best military line if the road is equally good.

Distribute transportation as directed in my letter of yesterday, except, if you deem advisable, give a limited number of provision wagons to each brigade or division. This is generally preferable to making the provision train entirely separate from the troops. Ten days' provisions will in that case go with each command.

Care should be taken about having provisions cooked in the morning for the days' march, and also, when in the vicinity of the enemy, to have at least two days' cooked provisions in the haversacks. If officers neglect this, the men suffer. Make marches at first short, so that the men may be kept in order and not overfatigued.

Very respectfully, your obedient servant,

H. W. HALLECK,

Major-General.

ROLLA, January 14, 1862.

Colonel E. A. CARR:

COLONEL: Fall back cautiously with the cavalry, keeping rear guard very strong, and a stationary picket, with no baggage except what they can carry on their horses, in rear, as long as you can safely. To cover your retiring movement, I send out infantry and artillery to meet and support you. Unless you are pressed by the enemy in force move slow, as I do not contemplate any further movement than enough to keep you out of danger of superior force. I think the storm must have checked the enemy, but I am now authorized to move other forces, and intend to bring different arms in proper proximity to each other. Keep the commanding officers of infantry and artillery and myself advised of your movements. You perceive the counter move which you make will cause a forward move here. Weather still very cold, but clear and moderating