Excerpt from Airplanes, Airships, Aircraft Engines General Order No. 57, dated July 2, 1921, Signed by the Secretary of the Navy, states that Report No. 91 of the National Advisory Committee, entitled 'nomenclature for Aeronautics' has been adopted as the official nomenclature for Aeronautics for use of the Army and Navy Air Services. 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.