CONTENTS 



CHAPTER 



PAGE 



Experiments and Exercises Ix 



I. The Meaning of Science 3 



II. Matter and Energy The Foundation of All Science . 12 



III. The Composition of Matter 22 



IV. The Air We Breathe 34 



V. Water 45 



VI. Water Power 67 



General Thought Questions for Discussion and Review .... 79 



VII. Heat . 81 



VIII. Some Applications of Heat 101 



IX. Weather 118 



X. Wind and Weather 131 



XI. The Heavens 148 



General Thought Questions for Discussion and Review .... 168 



XII. Sound 170 



XIII. Light 180 



XIV. Magnetism 195 



XV. Electricity 203 



XVI. Uses of Electromagnets 215 



XVII. Applications of Electricity 229 



General Thought Questions for Discussion and Review .... 240 



XVIII. Machines 242 



XIX. Transportation on Land 255 



XX. Transportation on the Water and in the Air .... 270 



XXI. Rocks and Soil 290 



General Thought Questions for Discussion and Review .... 310 



XXII. Protoplasm 312 



XXIII. One-Celled and Many-Celled Animals 319 



XXIV. Our Bodies 328 



vii 



