Excerpt from Elements of Chemistry One form of the machine is represented in Figure 4. It consists of a heavy iron frame, at one end of which is a box containing a stout steel spring. A pointer connected with this Spring moves over a graduated are on the top of the box. On the frame are two movable blocks, or slides, one of which is attached to the Spring, while the other may be carried backward and forward by means of a screw and crank. The rod whose tenacity is to be tried is stretched be tween the two slides, and the crank is then cautiously turned so as to pull upon the rod until it breaks. The force which is thus brought to bear upon the rod bends the spring; and the position of the pointer when the rod breaks shows how much force was required to pull the rod asunder. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.