At about 10.30 p. m. I received a dispatch from General Meade asking the progress of the bridge, to which I was able to reply at once that the last boat was in position, and the raft of three boats built ready to close the gap he had ordered left for the present, and that it was ready for completion in fifteen minutes at any time he ordered.

The gap was closed, but the bridge was not required or used until 6 a. m. the next morning, when the regulars were relieved and the bridge continued under my care with the volunteers, who carefully watched and repaired it every hour or oftener for the seventy- five or eighty hours it was down.

For the next forty hours after 6 a. m. of the 16th a continuous stream of wagons passed over the bridge (from 4,000 to 6,000 wagons) - some said fifty miles of wagons - and nearly all the artillery of this army, and by far the larger portion of the infantry and all its cavalry present, and even to its head of 3,000 or more of beef-cattle (the most injurious of all), without any accident to man or beast.

My officers and men were scarcely allowed any sleep during this time, nor myself as much even as four hours in the eighty hours preceding the taking up of the bridge, for it was in anxiety, not to say trembling, that I saw the destinies of this whole army of our country even committed to this single, frail, boat bridge, with steamers and other vessels drifting against it, and with much of its planking previously worn almost entirely through by careless use upon the Rappahannock, and I dared not stop the living stream of men and matter to sheath or protect it.

At length by 7 p. m. on the 18th the last animals were over and I breathed free again, and although the shelling of our troops across the river just before sunset within a mile above us gave us little hope of withdrawing the bridge in safety, it was ordered up and all rafted into three several tows before 3 a. m. of the 19th, and on its way to this point, which it reached about sunrise, the most successful effort on a large scale with pontoon bridging that has ever occurred in our country, if it does not rival those in any other land.

The bridge built over the Chickahominy by this same brigade about two years since was nearly as long as this, but built over a comparatively quiet and shallow stream - at least for nearly its whole extent - and with a great portion on trestles, and it was for but a small portion or one or two corps only of McClellan's army, while this bridge, besides some 200 feet of trestle-work, was for over 2,000 feet in pontoons, and for the greater part of the distance in deep water, in some parts up to eighty-five feet, with a very strong current running for a great part of the time, and it transported nearly all the material, artillery, and trains with the greater portion of the men of this large army.

You may be sure I was very well content and satisfied and felt like "him that putteth off his armor" when the affair was over.

Very respectfully, your obedient servant,

H. W. BENHAM,

Lieutenant-Colonel of Engineers and Brigadier-General.

* * * * * * *

MILITARY ACADEMY.

The Military Academy has continued to fulfill the purposes for which it was created, by collecting and procuring from all nations the arts and sciences connected with the defense of our country, and imparting this knowledge, so far as it is applicable to our people, to the cadets enjoying the benefit of a military education at this national institute.

The arm of service at this time calling for special attention is the artillery, which is still undergoing great modifications both for land and sea-coast application. The superintendent has asked an appropriation for this branch to enable him to lay before the student the various appliances that late wars have introduced, many of which serve to impart useful information, while numerous others are valuable in guarding us against the immense expense in attempting devices that have proved, on trial, to be failures - a degree of knowledge that is the saving of immense treasure if we profit by this experience.