of stone have been quarried, 920 yards of stone have been placed on parapets, and 131 yards of stone wall have been built. Details have been engaged cutting and hauling logs, running saw-mill, and constructing water-tanks.

FIRST REGIMENT MICHIGAN ENGINEERS AND MECHANICS.

This command has been engaged constructing block-houses on the railroad between Chattanooga and Marietta. Completed during the month nine block-houses. Eight others are nine-tenths finished. Detachments of this regiment are at work on the defenses of Stevenson and Bridgeport.

STEVENSON.

The force here has been engaged on the four block-houses remaining to be completed as per last report. Of these, three have been nearly completed and the fourth progresses rapidly. A portion of the detachment has been on picket duty.

BRIDGEPORT.

Block-houses her heave been virtually completed.

ENGINEER BRIGADE.

One regiment of this brigade was absent under Major-General Steedman. Until relieved from duty two regiments were at work on Lookout Mountain. Eight permanent hospital buildings have been completed, and two large reservoirs have been finished. Details have been running saw-mills and manufacturing lumber.

CHATTANOOGA.

Detachments of the First U. S. Veteran Volunteer Engineers have been engaged on earth-works and revetments of Forts Creighton, Phelps, Putnam, and Redoubt Jones, and on reserve magazine and water-works, also hauling and rafting lumber. One regiment of colored troops has been employed on the earth-works of Redoubt Carpenter and on the tunnel for water-works. Forty-five feet of tunnel remain yet to be run.

Respectfully submitted.

WM. E. MERRILL,

Colonel and Chief Engineer Department of the Cumberland.

[Inclosure Numbers 2.] HDQRS DEPARTMENT OF THE CUMBERLAND, OFFICE OF CHIEF ENGINEER, Chattanooga, Tenn., October 20, 1864.

Brigadier General R. DELAFIELD,

Chief Engineer U. S. Army, Washington, D. C.:

Report of operations of the topographical branch of the engineer office at the headquarters of the Department of the Cumberland, at Chattanooga, Tenn., during the month of September, 1864:

Tracings made. - Town plot of Chattanooga. Parts of Fayette and Henry Counties, Ga.

Photographic views taken. - Chattahoochee River railroad bridge, two negatives; Kenesaw Mountain, Ga. ; Rome, Ga. ; Marietta, Ga. ; Lulah