this institution in connection with the surgical and medical history of the war.

I have the honor to be, sir, very respectfully, your obedient servant,

JOSEPH K. BARNES,

Surgeon-General.

[OCTOBER 20, 1864. - For Hurlbut's General Orders,, Numbers 151, relating to the enrollment of militia in the Department of the Gulf, & c., see Series I, Vol. XLI, Part IV, p. 127.]

ENGINEER DEPARTMENT,

Washington, October 21, 1864.

Honorable E. M. STANTON,

Secretary of War:

SIR: I have the honor to present herewith the annual report of the operations of the Engineer Department for the fiscal year ending June 30, 1864:

As portions of this report present information which should be withheld from publication, it is recommended that such portions be not placed in the hands of the Public Printer. These portions are indicated by being furnished herewith in a special package.

DISTRIBUTION OF OFFICERS.

The operations of the Engineer Department and its officers during the year ending June 30, 1864, have embraced most branches of the profession and extended through most States of the Union on the Atlantic, Gulf, Pacific, and lake frontiers, and armies in the field opposed to the rebels.

The corps consists at present of eighty-six officers of all grades. Lieutenant-General Grant has had the services of twenty- one officers of the corps with the armies operating against Petersburg and Richmond. They have been occupied incessantly in the construction of field fortifications, reconnoitering the enemy's positions, building pontoon bridges and maneuvering the bridge trains, making surveys of the country occupied by the armies and plans of the siege works before Petersburg, and serving on the staff of the lieutenant-general and other general officers of the Army of the Potomac and James Rivers.

Major-General Halleck has had the services of two field officers on his staff attending to all the engineering duties of his bureau, while another field officer of the corps has been charged continuously with the defense of Washington City, with the co- operation and occasional assistance of several others.

The army under General Hunter had one subaltern officer upon whom devolved the duty of constructing bridges and collecting topographical information for the movement of the army in its march through the Valley of Virginia, thence to the Ohio and back to the valley.

The army under General Sherman has had nine field and subaltern officers assigned to it, who have labored continuously in the construction of defenses for the numerous bridges on the lines of railroad, in fortifying many strategic sites, besides cities and towns on the lines of communication, in making surveys, and reconnoitering expeditions to procure information of the strength and position of the enemy, and collect topographical data upon which to construct campaign maps