The Tube Muffle Furnace is practically the common laboratory analytical gas-fired combustion-furnace, with its glass tube replaced by the iron and copper tubes, G and M, and surrounded with brick-work to lessen radiation and to give better control over the temperature. The burners, J, are those of the common combustion-furnace. The bar, K, to be … Read more
In working brown iron-ore mines on the system employed at Longdale, namely, stoping from the top down, the usual procedure is to drive a succession of upraises from the lowest adit to the highest, or to the top of the deposit, as the case may be. These upraises are usually driven 120 feet apart, along … Read more
The magnetic concentration of iron-ores has been so often and so widely studied and discussed among the members of the Institute that any remarks concerning its general importance, from an economic standpoint, would be superfluous; but it is thought that a description of the Ball and Norton ore-separator, designed for cobbing and separating magnetic iron-ores, … Read more
The Transactions of the Institute contain nothing, as yet, on the subject of pocket-compasses; and in the belief that American miners, explorers, geologists, and engineers will gladly welcome any information about new forms of apparatus, simple in construction and adapted to rapid use, I offer a short description of an improved French combination pocket-compass, which, … Read more