Produced by Chris Curnow, Ernest Schaal, and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) LECTURE ON ARTIFICIAL FLIGHT GIVEN BY REQUEST AT THE ACADEMY OF NATURAL SCIENCES AT San Francisco, California, August 7th, 1876, BY WM. G. KRUEGER WITH REFERENCE TO A MODEL OF HIS OWN INVENTION. INDEX. No. Page. 1 Introduction 1 2 History and Fable 2 3 Discovery of the Balloon 7 4 Noted Air Voyages 8 5 Absence of Danger 11 6 Charm of Ærial Travel 12 7 Ærial Voyages Health Promoting 15 8 Parachutes 16 9 The Kite 17 10 Balloons Impracticable 18 11 Reasons why the Problem has remained Unsolved 21 12 Fundamental Principles in Flight 23 13 Weight 24 14 Surface 26 15 Power 28 16 Flying Creatures, their Proportions, Movements 31 17 Mechanical Practicability of Flight 34 18 Flying Machines of the Present, their defects 37 19 The Practical Air Ship of the near Future 43 20 What Ærostation will Accomplish 48 21 Closing Remarks 50 * * * * * ERRATA. Page 4, line 4, read "one from Koenigsberg," for "Koenigsberg." Page 4, line 18, read "afterward," for "ago." SAILING IN THE AIR. I.--INTRODUCTION. _Gentlemen of the Academy_: