evidently been destroyed by this action. In a brass model of a pistol of the time of Charles II., from the United Service Museum, there was an ingenious attempt to cause the chamber to rotate, by mechanical action, in some degree similar, but more complicated than the arms constructed by the author. The "Coolidge" and the "Collier" guns, both flint guns of comparatively modern manufacture, exhibited the same radical defects of liability to premature explosion. The invention of Nock's patent breech, and the Rev. Mr. Forsyth's introduction of the detonating or percussion guns, which latter principle, with the necessary mechanical arrangements for the caps, was essential to the safe construction of repeating fire-arms, constituted a new era in these weapons. Colonel Colt gave a detailed and interesting account of his experiments, which resulted in the invention of his celebrated revolvers. His communication, the first that had been brought before the institution, by an American, was received with acclamations; and in the discussion which ensued, in which our Minister, the Hon. Abbott Lawrence, Captain Sir Thomas Hastings, R.N., Captain Sir Edward Belcher, R.N., Captain Riddell, R.N., Mr. Miles, and the members of the council took part, the most flattering testimony was given of the efficiency of the revolvers in active service, and the strongest opinions as to the necessity of their use in all frontier warfare; and that without this arm it was almost impossible, except with an overwhelming force of troops, to cope with savage tribes. The discussion was resumed at a meeting of the Institution, held on the second of December. A new, and, we understand, a very important invention, in this line, is also described in the following interesting article by a contributor to the _International_: SKETCH OF THE PROGRESS OF INVENTION IN OFFENSIVE ARMS: JENNING'S RIFLE. WRITTEN FOR THE INTERNATIONAL MAGAZINE, BY W. M. FERRIS.