They are the work of Mr. George N. Barnard, photographer at the chief engineer's office, Military Division of the Mississippi.

All of which is respectfully submitted.

ORLANDO M. POE,

Captain of Engineers.

Lieutenant Colonel J. H. SIMPSON, U. S. Engineers,

Cincinnati, Ohio.

SIR: In accordance with your instructions, I have the honor of reporting as follows upon the engineer operations arising from the recent attempt of the enemy to gain possession of East Tennessee:

On the morning of November 13, 1863, information was received at the headquarters of the Army of the Ohio that the enemy, under the command of Longstreet, had succeeded in building a pontoon bridge over the Holston River at Huff's Ferry, near Loudon, and was crossing in force. The major-general commanding at once started for that point, taking with him a portion of his staff. I was directed to remain at Knoxville, in anticipation of instruction for the defense of that place.

From Campbell's Station, on the 16th November, I was directed to select lines of defense around Knoxville, and to have everything prepared to put the troops in position as fast as they should arrive.

As I had been over the ground a great many times, and had examined it with reference to this contingency, the examination directed was made very rapidly. I had made it a point to familiarize myself, as far as possible, with the organization of the Army of the Ohio, and was consequently able to designate, in writing, the positions to be occupied by the several subdivisions, as follows:

Romer's battery of four 3-inch rifle guns, at the University, to be supported by one brigade (Morrison's) of the First Division, Ninth Army Corps; Benjamin's battery of four 20-pounder Parrotts, and Buckley's battery of six 12-pounder Napoleons (light twelves), at fort on hill northwest of the University; these batteries being supported by the remaining two brigades (Humphery's and Chirst's) of the First Division, Ninth Army Corps, the ground to be occupied by this division, extending from the Holston River, near the mouth of Second Creek, around to the point where the East Tennessee and Georgia Railroad crosses Second Creek. This line was nearly at right angles to the river, to the position of Benjamin's battery, and thence parallel to the river.

Gittings' battery of four 10-pounder Parrotts, to occupy the small earth-work on Vine street near the depot.

The Fifteenth Indiana Battery of three 3-inch rifle guns, to occupy the ridge between Gay street and First Creek; these two batteries to be supported by the Second Division, Ninth Army Corps, extending from Second Creek to First Creek, and parallel to the railroad.

The Twenty-fourth Indiana battery (Captain Sims) of six James' rifle guns (3.8-inch caliber), and Henshaw's battery of two James' rifle guns and four brass 6-pounders, to occupy the fort on Temperance Hill and the ridge adjacent, supported by Chapin's brigade of White's division and Reilly's brigade of Hascall's division, of the Twenty-third Army Corps, extending from First Creek eastward to