Having given a sketch of each of the superintendents, the writer thinks a notice due to the master-armorers, also. Originally, the superintendents were styled master-armorers, and Messrs. Perkins and Stubblefield went by this appellation officially. In 1815, however, the latter gentleman was allowed an assistant to whom that title was transferred, and that of superintendent was given to the principal officer. In the above mentioned year, Armistead Beckham was appointed to the second office in the armory. He was a high-minded gentleman who did his duty regardless of the clamor of factions and with a stern resolve to do justice--a difficult task during a portion of his time, as the administration at Washington was democratic and Mr. Beckham was always much opposed to President Jackson. The latter, however, could not be induced to dismiss the honest master-armorer--such was the respect entertained for the character of that gentleman. In 1830 Mr. Beckham exchanged with Benjamin Moore, who occupied a similar position in Pittsburg, each taking the place of the other. In some time after, Mr. Beckham was appointed superintendent of the Western Penitentiary of Pennsylvania, in Allegheny City, which position he held until his death, many years after. Benjamin Moore was a remarkable person. He was a fine specimen of the physical man and his mind was on the same scale as his body. He occupied the position of master-armorer at Harper's Ferry for nineteen years and, during that time, he introduced an improvement into the manufacture of arms which is universally admitted to be of utmost advantage, but for which neither he nor his heirs ever received compensation, although a claim for it has been pending for many years. His invention was that of the interchange of the component parts of a gun, which means that any particular part will suit any gun. The advantage of this plan in field operations must be at once apparent as, from piles composed of the various parts of a rifle or musket, a gun can be extemporized to replace one rendered useless by accident. It is to be hoped that his descendants may yet reap the benefit of his ingenuity and that justice may at length be done to the heirs of a man who did so much for the efficiency of our armies.