Page:Popular Science Monthly Volume 38.djvu/350

This page has been proofread, but needs to be validated.
336
THE POPULAR SCIENCE MONTHLY.

Fig.30—A Modern Forge.

varied with the height through which the "hammer-block" was allowed to fall, and this height could be regulated within the limits of the full stroke of the hammer by means of the valve-gear. As soon as the blow had been delivered, the mechanism for effecting the upward movement of the hammer-block came