Excerpt from Instructions for Mounting, Using, and Caring for 6-Inch Rapid-Fire Gun, Armstrong and 6-Inch Barbette Carriage, Armstrong The breech of the gun is closed by a screw formed in two steps, the front step being tapered, and of less diameter than the rear; both steps have three portions of their thread removed, each one-sixth of a turn, the threads on one step standing opposite to the blank spaces on the other; this arrangement distributes the strain all round the circumference of the breech screw. The interior of the gun at the breech is prepared in a similar manner, and admits of the breech screw being swung into place and locked by a simple mechanism, to be described. The breech screw is supported by a carrier, P, on which it is free to revolve through an angle of 60 degrees; the carrier is hinged to the right side of the breech ring, so that the screw can swing clear of the breech opening for loading. The screw is secured on the carrier by means of the s, t0p bolt D. The breechblock is unscrewed and withdrawn from the gun by a single horizontal movement of the hand-looking lever L, which is pivoted on the right side. A projecting pin PI is screwed into the rear face of the breech screw. 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.