*ON THE CONSERVATION OF ENERGY.* By Professor BALFOUR STEWART. Fourteen Engravings. Price 5s. *ANIMAL MECHANICS: or, Walking, Swimming, and Flying.* By Dr. J. B. PETTIGREW, M.D. F.R S. 130 Illustrations. Price 5s. *RESPONSIBILITY IN MENTAL DISEASE.* By Dr. HENRY MAUDSLEY. *THE ANIMAL FRAME.* By Prof. E. J. MAREY. 119 Illustrations. Crown 8vo. Price 5s. *THE NEW CHEMISTRY.* By Prof. JOSIAH P. COOKE, of the Harvard University. Numerous Engravings. Price 5s. ☞ For List of forthcoming Volumes, see end of the book. HENRY S. KING & CO. 65 CORNHILL, and 12 PATERNOSTER ROW. [Illustration: _C. Berjeau_ _W. Ballingall_ WALKING, SWIMMING, AND FLYING.] ANIMAL LOCOMOTION OR WALKING, SWIMMING, AND FLYING, WITH A DISSERTATION ON AËRONAUTICS. BY J. BELL PETTIGREW, M.D. F.R.S. F.R.S.E. F.R.C.P.E. PATHOLOGIST TO THE ROYAL INFIRMARY OF EDINBURGH; CURATOR OF THE MUSEUM OF THE ROYAL COLLEGE OF SURGEONS OF EDINBURGH; Extraordinary Member and late President of the Royal Medical Society of Edinburgh; Croonian Lecturer to the Royal Society of London for 1860; Lecturer to the Royal Institution of Great Britain and Russell Institution, 1867; Lecturer to the Royal College of Surgeons of Edinburgh, 1872; Author of numerous Memoirs on Physiological Subjects in the Philosophical and other Transactions, etc. etc. etc. _ILLUSTRATED BY 130 ENGRAVINGS ON WOOD._ HENRY S. KING & CO. 65 CORNHILL, AND 12 PATERNOSTER ROW, LONDON. 1873. [Illustration: (_All Rights reserved._)] PREFACE. In the present volume I have endeavoured to explain, in simple language, some difficult problems in “Animal Mechanics.” In order to avoid elaborate descriptions, I have introduced a large number of original Drawings and Diagrams, copied for the most part from my Papers and Memoirs “On Flight,” and other forms of “Animal Progression.” I have drawn from the same sources many of the facts to be found in the present work. My best thanks are due to Mr. W. Ballingall, of Edinburgh, for the highly artistic and effective manner in which he has engraved the several subjects. The figures, I am happy to state, have in no way deteriorated in his hands. ROYAL COLLEGE OF SURGEONS OF EDINBURGH, _July 1873_. [Illustration] CONTENTS. ANIMAL LOCOMOTION. INTRODUCTION. PAGE Motion associated with the life and well-being of animals, 1 Motion not confined to the animal kingdom; all matter in motion; natural and artificial motion; the locomotive, steamboat, etc. A flying machine possible, 2