CONTENTS XI 



CHAPTEE VI 



APPLICATIONS OF CHRONOPHOTOGRAPHY TO MECHANICS 



PAGE 



Summary. — Bodies falling in air — Ballistic experiments — The 

 resistance of the air to surfaces variously inclined — Applica- 

 tions of chronophotography to hydrodynamics — Fluid veins ; 

 changes in shape of fluid waves ; intrinsic movements of 

 fluid waves — Currents and el dies— Influence of the shape 

 of bodies placed in currents — Oscillations and vibrations — 

 Rolling of ships — Vibrations of metal bridges ... 84 



CHAPTER VII 



CHRONOPHOTOGRAPHY ON MOVING PLATES 

 Principles and History of the Method 



Summary. — Janssen's astronomical revolver — Muy bridge's ex- 

 periments : luminous background — Photographic cameras ar- 

 ranged in series — Control of the instantaneous shutter by 

 electrical means — Photographic gun — Internal structure of 

 the instrument - Method of changing the photographic plates 

 — Principles of chronophotography on moving plates— Em- 

 ployment of chronophotography — Necessity for arresting the 

 progress of the film at th« moment of exposure — Moment to 

 choose for taking the photograph — Form and dimensions 

 of the photographs — Regulation of the number and dimen- 

 sions of the photographs — Reproduction, enlaigement, and 

 reduction of chronuphotographs 103 



CHAPTER VIII 



HUMAN MOVEMENTS 



From the Point of View of Kinetics 



Summary. — Some movements in man; the study of them by the 

 graphic method — Speed of different paces in man ; relation- 

 ship between the frequency and length of stride — Duration 

 of the rise and fall of the foot in walking and running — 

 Path described by any particular part of the body during 

 different paces ; mechanical means of recording it — The 

 study of movements in man by means of chronophotography 

 on fixed plates ; long-jumping ; high-jumping — Skilled move- 

 ments, fencing, etc. — Jumping from a height — The swing of 

 the leg in walking 126 



