CONTENTS 



CHAPTER I 



TIME 



Its Graphic Record ; Time-measurement by means of Photography 



PAGE 



Summary. — Graphic record of time— Chronography— Rudiments 

 of the method — Transmission of movement to the recording 

 needle which registers the duration — L'hronographic record 

 of a man's foot in walking, during the phases of rest and 

 motion — The same of the four feet of a horse in its various 

 paces — Record of the fingering of a pianist — Applications 

 of photography to the registration of time -Measurement of 

 the exposure allowed by a photographic shutter — Measure- 

 ment of the time intervals between successive exposures . 1 



CHAPTER II 



SPACE 

 Its Measurement and Representation by Photography 



Summary. — Tendency to replace outline drawings, plans, and 

 diagrams in relief by photography — Photography traces the 

 various positions in space occupied by a moving body — 

 Photographic trajectory of the movements of a point in 

 space ; its stereoscopic trajectory — Movements of a straight 

 line in space — Solid figures formed thereby : cylinders, 

 hyperboloids, cones, etc. — Movements of a curve in space ; 

 photography of the figures which it forms : spheres, ellip- 

 soids, etc. — Stereoscopic pictures of figures of three dimen- 

 sions — Figures formed by the movement of solid bodies; 

 effects of light and shade 18 



