CONTENTS 



CHAPTER 



I. HEAT 



9 



II. TEMPERATURE AND HEAT 27 



III. OTHER FACTS ABOUT HEAT . . . . 31 



IV. BURNING OR OXIDATION 45 



V. FOOD .60 



VI. WATER 70 



VII. Am ' . . .81 



VIII. GENERAL PROPERTIES OF GASES 95 



IX. INVISIBLE OBJECTS . ,. 100 



X. LIGHT 104 



XI. REFRACTION 113 



XII. PHOTOGRAPHY .... .... 126 



XIII. COLOR 134 



XIV. HEAT AND LIGHT AS COMPANIONS 142 



XV. ARTIFICIAL LIGHTING 148 



XVI. MAN'S WAY OF HELPING HIMSELF 154 



XVII. THE POWER BEHIND THE ENGINE 176 



XVIII. PUMPS AND THEIR VALUE TO MAN 187 



XIX. THE WATER PROBLEM OF A LARGE CITY . . . 206 



XX. MAN'S CONQUEST OF SUBSTANCES ... . . .218 



XXI. FERMENTATION 232 



XXII. BLEACHING 237 



XXIII. DYEING ... 244 



7 



