From Colonel Spaulding's report:

The weather has been so clod and windy during the past week that but little could be done on the signal tower. The posts have all been raised and secured in their positions and twenty-six additional feet of the tower completed at this date. Brevet Major Hine reports that three or four days of mild weather will enable him to complete the work.

On the 4th Instant Captain Dexter, with a detail of two companies from this command, commenced delivering material for and constructing a strong line of abatis around Fort Fisher. On the 5th this abatis was completed on the front and flanks, and sufficient material delivered for extending it along the rear face, but this could not be placed in positions until the camps in that vicinity were removed. This abatis was further strengthened by two lines of wire interlaced with the branches and a wire entanglement placed in front of the abatis.

On the 6th Captain Dexter commenced opening a road from Fort Cummings to Armstrong's Mill, on Hatcher's Run. The details for this work were, two companies from this command from the 6th to the 9th, inclusive, 14 teams from the Second Corps on the 8th instant, and 400 men and 40 teams from the Ninth Corps on the 9th. The work was finished on the evening of the 9th, having constructed double corduroy bridges over all the ravines and low grounds and cut a double track through the timber.

On the evening of the 5th I sent Brevet Major Van Brocklin, with four companies of this command, to report to you on the crossing of Hatcher's Run. On the 6th this detachment was engaged in repairing the Vaughan road, building corduroy bridges over small streams, &c. At 9 p. m. of the 6th Major Van Brocklin received orders from you to construct an additional bridge over Hatcher's Run. This bridge was about 250 feet in length; the material was carried from the woods by Major Van Brocklin's detachment, and the bridge completed about 1.30 a. m. of the 7th instant.

On the morning of the 7th I sent an additional company from this regiment to report to Major Van Brocklin, and he commenced the construction of a permanent corduroy road from Hatcher's Run to Fort Siebert. The following details have been engaged on this work: February 7, five companies Fiftieth Engineers and 20 men and 100 teams from Second Corps; February 9, five companies Fiftieth Engineers and 2,000 men and 100 teams from Fifth Corps; February 10, five companies Fiftieth Engineers and 2,000 men and 100 teams from the Fifth Corps. This corduroy road is now completed for about three miles, with the exception of covering a portion of it with earth.

On the 8th Major Van Brocklin, leaving Captain Van Rensselaer in temporary charge of the work on the corduroy road, made a reconnaissance for an extension of the U. S. military railroad to hatcher's Run, and reported the result to Colonel Batchelder, chief quartermaster, Army of the Potomac.

On the 9th Captain Van Rensselaer took charge of the unfinished work on Fort Fisher, this work having been turned over to him by Captain Howell.

The repairs of the several forts on the rear line, which were commenced on the 19th of January by Captain Dolan, were as follows: At Fort Stevenson, the ramps, banquettes, and gun platforms required repairs, about fifty feet of the scarp on each face to be rivetted, gratings to be placed over the drains, the entrances of three magazines to be reverted, and the exterior to be removed from the bern and dressed off; at Fort Blaisdell, the whole revetment and parapet to be moved in four feet, gun platforms, banquettes, ramps and embrasures to be rebuilt. The above works in these two forts are completed. The work on Fort Patrick Kelly was about the same as tat on Fort Blaisdell. The revetment on this forts has been moved in and the barbettes nearly completed, but owing to troops being taken away for the late movement on Hatcher's Run, the work on this fort was suspended. The work on Fort Bross required the revetment and parapet to be moved in four feet, the ditch to be drained, embrasures cit in the parapet and reverted, and a magazine to be built. This work is completed except the art work in moving the parapet; it was left unfinished at the time of the late move of the army. To complete these works would probably require a detail of about 400 men for three days. Four hundred and ninety-six gabions have been made during the week and brought into camp, and 480 issued at Fort Fisher, the battery on the left of this fort, and for repairs of the works on the Ninth Corps line.

Very respectfully, sir, your obedient servant,

J. C. DUANE,

Major of Engineer and Brevet Colonel, U. S. Army.

Bvt. Major General J. G. BARNARD,

Chief Engineer, Armies in the Field, City Point, Va.