The metal of which cannon are made
--The appeal of Gen. Beauregard to the people of Tennessee to furnish metal to be cast into cannon for the Confederacy, having elicited the voluntary contributions of the patriotic men and women of the South, the following letter from Adjutant Gen. Wayne to a lady of Georgia, containing valuable information on the subject of the composition of gun metal, will be read with profit and interest:If Gen. Beauregard, in his appeal to the planters of the Mississippi, meant anything more than to arouse their slumbering patriotism to active exertion, he wanted the tin of which their balls are partly composed. We have the copper, but for the fabrication of brodes, (commonly, but erroneously called brass guns,) we want tin. That you may understand this, I will tell you that science has determined for guns, as best, the proportions of nine pa 's of copper to one part of tin; and for bells seven or eight parts of copper to three parts of tin. By having a large number of bells, therefore, we can add two or three times the weight of copper, as analysis may determine their composition and bring them to the standard of gun metal. The lightest field place in our batteries — a six-pounder — weighs, on an average, eight hundred and eighty-four pounds. For the casting of a six-pounder, therefore, at least one thousand pounds of metal would be necessary.--Bronze guns are used in field batteries only for their lighter weight, by which the battery is more readily moved. They are not so durable as iron. science, within the past five years, has opened the way for casting iron guns of sufficient lightness for field uses, and there is not a foundry in the Confederacy that is not now working to its utmost ability. If there is I should like to know it, and it should not be idle long.
The tin referred to is block tin, not sheet tin, which is only sheet iron washed with a solution of tin.
