(1) Liquid Pressure 36 (2) Transmission of Liquid Pressure 41 (3) Archimedes' Principle 47 (4) Density and Specific Gravity 52 CHAPTER IV. MECHANICS OF GASES. (1) Weight and Pressure of the Air 55 (2) Compressibility and Expansibility of the Air 62 (3) Pneumatic Appliances 66 CHAPTER V. FORCE AND MOTION. (1) Force, how Measured and Represented 79 (2) Motion. Newton's Laws 85 (3) Resolution of Forces 96 (4) Moment of Force and Parallel Forces 99 (5) Gravitation and Gravity 103 (6) Falling Bodies 109 (7) The Pendulum 115 CHAPTER VI. WORK AND ENERGY. (1) Work and Energy 119 (2) Power and Energy 123 (3) The Lever and Simple Machines 129 (4) Wheel and Axle and Pulley 136 (5) Efficiency and the Inclined Plane 142 (6) Friction and its Uses 147 (7) Water Power 152 CHAPTER VII. HEAT, ITS PRODUCTION AND TRANSMISSION. (1) Sources and Effects of Heat 159 (2) Temperature and Expansion 162 (3) Expansion of Gases, Liquids and Solids 167 (4) Modes of Transmitting Heat 173 (5) Convection, Heating and Ventilation 179 (6) The Moisture in the Air, Hygrometry 191 (7) Evaporation 196 CHAPTER VIII. HEAT AND WORK. (1) Heat Measurement and Specific Heat 200 (2) Heat and Changes of State 205 (3) Heat and Work 212 (4) Heat Engines 222 CHAPTER IX. MAGNETISM. (1) General Properties of Magnets 228 (2) Theory of Magnetism, Magnetic Fields 232 (3) The Earth's Magnetism 238 CHAPTER XI. STATIC ELECTRICITY.