Practical Aeronautics: An Understandable Presentation of Interesting and Essential Facts in Aeronautical Science (Classic Reprint)

Excerpt from Practical Aeronautics: An Understandable Presentation of Interesting and Essential Facts in Aeronautical Science<br><br>Early Attempts. Leonardo da Vinci devoted some time to the problem of artificial ?ight. His sketches show the details of bat like wings which were to spread out on the downward stroke and fold up with the upward stroke. Francisco de Lana planned to make a ?ying ship the appearance of which was somewhat like that shown in Fig. I by exhausting the air from metal spheres fastened to a boat.<br><br>About the Publisher<br><br>Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com<br><br>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.