CONTENTS. 



PART I. SUCCESSES. 



CHAPTER PAGE 



I. MODES OP TRAVELLING, 1 



II. LABOR-SAVING MACHINERY, ..... 12 



III. THE CONVEYANCE OF THOUGHT> . . 17 



IV. FIRE AND LIGHT, ... .24 

 Y. NEW APPLICATIONS OF LIGHT PHOTOGRAPHY, . 31 



VL NEW APPLICATIONS OF LIGHT-SPECTRUM ANALYSIS, 42 



VII. THEORETICAL DISCOVERIES IN PHYSICS, . . 51 



VIIL MINOR APPLICATIONS OF PHYSICAL PRINCIPLES, . 59 



IX". THE IMPORTANCE OF DUST A SOURCE OF BEAUTY 



AND ESSENTIAL TO LIFE, 69 



X. A FEW OF THE GREAT PROBLEMS OF CHEMISTRY, . 86 



XI. ASTRONOMY AND COSMIC THEORIES, .... 93 



XII. GEOLOGY : THE GLACIAL EPOCH AND THE ANTIQUITY 



OF MAN, 110 



XIII. EVOLUTION AND NATURAL SELECTION, . . .135 



XIV. POPULAR DISCOVERIES IN PHYSIOLOGY, . . .143 

 XV. ESTIMATE OF ACHIEVEMENTS : THE NINETEENTH 



AS COMPARED WITH EARLIER CENTURIES, . .150 



