Page:Popular Science Monthly Volume 8.djvu/323

Rh cast-iron letters which act as stencils. Thus equipped, the contractor is able to turn out three hundred head-stones a day, upon each of which is a handsomely-cut inscription averaging eighteen raised letters. It is estimated that, to accomplish a like result by the old process, a force of three hundred men would be needed. Another instance of the rapidity with which these little sand-engines do their work is shown in the engraving of glass globes, tumblers, etc., which can be done at the astounding rate of one a minute.



Extended space might be devoted to a mere recital of the actual present accomplishments of the sand-blast, and, were we to enter the field of speculation as to its possibilities, the range of its adaptation would tax the reader's credulity. We will therefore be content to refer to the following extract from the report of the judges at the fortieth exhibition of the American Institute, which, in awarding the inventor the great medal of honor, describes and commends his invention as follows: