what seemed to me silver was, in reality, a peculiar variety of steel, coated with an extremely hard alloy of aluminum.
"Even in your day," said my informant, the ores of this metal were known to be more abundant than those of iron even. But, as none but expensive methods were known for extracting it from its ores, aluminum remained of slight practical importance. Since then processes have been discovered that render aluminum and other kindred metals as abundant as iron. On account of its lightness, and the slowness with which it tarnishes in the air, this metal is now preferred to iron for numberless purposes. Even when iron is employed, it is generally coated with this alloy, which preserves it from rust, and makes the use of machinery much cleanlier,—a matter of no slight importance, as machines are used for every purpose.
"That machine you see before you is a regulator, an indispensable article of household furniture. It supplies, or, rather, distributes, the motive-power required for any purpose to which machinery is applicable."
"But why is so much glass employed in these machines?" said I. "The mere vibration should be sufficient to utterly destroy it."
"Here is the explanation," he replied, and struck with all the power of his arm a heavy blow against the immense window-pane.
I started in consternation, expecting to see the splendid sheet of glass shattered, with all sorts of unpleasant consequences. The only result, however, was a dull, muffled sound, as if he had struck the side of a boiler.
