Having carefully examined them, I am convinced they are inefficient for the purposes intended, so far as I understand what those purposes are. Bolivar Heights, the key to this post, a position of great strength, commanding one of the main approaches, is without works for guns of any caliber. It is true the guns of Fort Duncan, on the Maryland side, command these heights and the entire length of their crest, the nearest point being 1,250 yards, and the most distant only 2,900 from that work. These heights are commanded, and would be enfiladed, by enemy's batteries from Loudoun Heights, on the opposite side of the Shenandoah, could batteries be established there. But our guns on Maryland [Heights] so completely command Loudoun [Heights] that it may be regarded as altogether impracticable for those heights to be held by an enemy while Maryland Heights are in our possession. This condition of defenses is such that an enterprising enemy can easily possess themselves of Bolivar Heights, and hold them without serious damage from the guns of Fort Duncan by the construction of a few traverses for the protection of gunners, the labor of a single night. That position in the possession of an enemy of sufficient force to attempt the capture of this place by seige or coup de main, would compel the withdrawal of our troops to the Maryland side. There the natural difficulties of attack and the strength of our works would secure small forces against five times their numbers.

We should have, then, the singular spectacle of a place commanded by two contending armies while neither can hold or occupy it. The bridge and the railroad would then fall into the power of the enemy, and by night enterprise of small parties could be destroyed. It would be impossible for the forces on Maryland Heights to prevent such destruction.

If, as I suppose, one of the main purposes of holding Harper's Ferry and the erection of the defenses already made here is to protect the Baltimore and Ohio Railroad, it seems to me certain that such intention may be defrauded, because of the failure to fortify Bolivar Heights, the main key and strength of this position on the Virginia side. If, in fact, Harper's Ferry is of any considerable military importance, either for the protection of the railroad, to hold Maryland from invasion, or as an exterior defense to aid Washington, and is to be held at any cost, I conceive it to be essential to fortify strongly Bolivar Heights.

With these views, I ask the major-general commanding the department to order an experienced engineer officer to report to me without delay, to plan defenses for Bolivar Heights, to superintend their construction, and to determine the number and caliber of guns needed to arm them.

I am, colonel, very respectfully, your obedient servant,

B. S. ROBERTS,

Brigadier-General, Commanding.

CIRCULAR.] BALTIMORE, MD., March 16, 1863.

(Addressed to the military officers stationed along the line of the Baltimore and Ohio Railroad, the Potomac River, and at all points within this department between the meridians of Washington, D. C., and Piedmont, Va., form which goods are carried into Virginia.)

The major-general commanding the department and Eighth Army Corps directs me in this manner to enjoin upon all officers stationed as above mentioned a strict enforcement of General Orders, Numbers 6, issued on the 14th day of January, 1863, prescribing regulations for the trans-