to Mr. Ames to manufacture fifteen of them for the Government, the condition being that the guns should be superior to any rifled guns in the service. One of these guns was fired under the direction of a board of officers, who unanimously expressed the opinion that the "Ames wrought-iron guns possess, to a degree never before equaled by any cannon of equal weigh offered to our service, the essential qualities of great lateral and longitudinal strength, and great powers of endurance under heavy charges; that they are not liable to burst explosively and without warning, even when fired under very high charges, and that they are well adapted to the wants of the service generally, but especially whenever long ranges and high velocities are required." The Board also expressed the opinion that the fifteen Ames 7-inch guns possessed sufficient weight and strength to receive an 8-inch bore, and recommended that the gun which had been fired under their direction should be reamed up to eight inches and subjected to further trial.

They further decided that Mr. Ames had fulfilled the obligation incurred by him in his contract to furnish the gun, and that so many of the guns as should endure a proof of ten rounds with the service charge, and pass the proper inspection, should be accepted and paid for.

Two of the fourteen guns burst in proof, exhibiting serious defects in their manufacture-defects in welding-which I had been apprehensive could not be avoided. The guns which endured the proof of ten rounds where accepted and paid for by this Department.

The guns which was fired under the direction of the Board was bored up to eight inches and fired twenty-four times with service charges, when it burst, exhibiting the same defects that were developed in the other guns which burst. The failures in subsequent firing indicate that these guns cannot be relied upon, and that no more of them ought to be made for the department.

Believing that, with our present knowledge of the properties of metals and our skill in working them, reliable rifle guns of large caliber can be made of cast-iron, I have with your sanction, caused a pair of 8-inch rifle guns of the supposed proper model and weight to be made. These guns are now at Fort Monroe undergoing extreme proof, and should their endurance be satisfactory it is proposed to have other guns like them made.

NATIONAL ARMORY.

The capacity of this establishment for the manufacture of muskets was not increased after the date of my last report, and upon the conclusion of hostilities, in view of the large number of muskets on hand of a model which will probably become obsolete very soon, the manufacture was reduced as rapidly as it could be done with economy; and at present no new muskets are being assembled. Only those parts which were in different stages of advancement are being finished.

In my last report I stated that it was in contemplation to change the manufacture at the National Armory as soon as the best model for a breech-loading musket could be established, and that details for effecting this measure would receive the early attention of this Bureau. Extensive experiments have been made by a board of officers, and also under my direction and supervision, to effect that object; but as yet no arms has been presented which I have been willing to recommend for adoption. The selection of a proper mode is considered so