Excerpt from Compressed Air Magazine, Vol. 15: January to December, 1910 The half - tone herewith shows the arrange ment which has revolutionized all this. It is the invention of Mr. C. H. Locker, of'the firm above referred to. It comprises in fact a single rock drill with a carriage and mounting and air-power devices which enable it to keep at work, actually drilling, as constantly as pos sible and minimize the delays required for shifting from hole to hole, for changing the steels, and for raising the drill by the feed screw when either change is made. This drill has largely made its record by avoiding stops, just as the big through express trains do. It has also the additional advantage of extra weight and power, which would not be prae tically available in a drill entirely operated and moved about by hand. 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.