folk the great of my force. The rebels have finished the railroad from Petersburg to the Blackwater. The secessionists were cooking for them at Suffolk night before last with the assurance that they were to be there yesterday. I beg you to let Peck's division remain at present. He is superintending the armament of Yorktown. I have not a single artillery, ordnance, or engineer officer for that post.

JOHN A. DIX,

Major-General.

HEADQUARTERS SEVENTH ARMY CORPS,
Fort Monroe, Va., September 20, 1862.

Major General H. W. HALLECK,

General-in-Chief:

GENERAL: I requested by telegraph that General Peck's division might not be taken away from me at present, assigning, briefly, the reasons. I do so now more in detail.

My aggregate force present on the 10th instant was as follows:

Fort Monroe........................... 520

Camp Hamilton.........................3,330

Newport News.......................... 518

Norfolk...............................2,021

Suffolk...............................3,454

Yorktown and Gloucester...............3,868

Williamsburg.......................... 817

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14,528

Deduct sick................................. 1,384

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13,144

Add four new regiments, about............... 3,400

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Total....................................... 16,544

Since the 10th I have, in order to meet a threatened movement against Suffolk, augmented my force there to about 8,500, and left at Camp Hamilton only one regiment.

Suffolk.-This is at the moment my most important position. The enemy has just finished he railroad from Petersburg to the Blackwater, 20 miles from Suffolk, and on Tuesday and Wednesday moved a considerable body of infantry to that point. There was a force of cavalry and artillery in the vicinity before. On Thursday I went to Suffolk with reasonable assurance that there would be an advance on us, and examined the preparations made for defense by General Ferry.

The gauge of the Norfolk and Petersburg Railroad is 5 feet, and the gauge of the Norfolk and Weldon, or Seaboard, 4 feet 8 1/2 inches. Having no locomotives for the former we altered the gauge to 4 feet 8 1/2 inches from Norfolk to Suffolk, connecting the two roads at the latter point by a Y, so as to use the equipment on either road at pleasure. Since the enemy have completed their road from Petersburg to the Blackwater I have been altering the gauge from Suffolk to Blackwater, so as to render it useless to them and advantageous to us if we wish to thrown a force down from Suffolk, thus enabling us to control this communication as far as the Blackwater. We are out some 6 miles, and are altering 3 miles a day. When you decided to hold Suffolk I determined to make it as effective as possible, and this change of gauge may be of great importance if we are in force again in this quarter and in North Carolina. To effect this object I must have troops, and the number I now have there may be indispensable to enable me to hold the place