CONTENTS 



CHAPTER I. 

 Matter and Its Measurement 1 



The Earth and Science. Phenomena. The Scientific Way or 

 Method. Matter. Substances. How We Measure Space and 

 Matter. Common Units of Length. The Metric System. The 

 Standard Meter. Metric Tables of Length, Area, and Volume. 

 Larger Units of Length. Weight. Units of Weight. Metric 

 Units of Weight. Bureau of Standards. Summary. Exercises. 



CHAPTER II. 

 Force and Energy . 17 



Gravity. Gravitation. Mass and Weight. Falling Bodies. 

 Exercises. Force. Force of Expanding Gases. Work and Energy. 

 Power. Inertia of Matter. Flying from the Center. Exer- 

 cises.* Cohesion and Adhesion. The Surface of a Liquid. Capil- 

 lary Action. Density and Specific Gravity. Buoyant Force of 

 Liquids. Center of Mass or Gravity. Summary. Exercises. 



CHAPTER III. 

 Air and Fire 38 



The Atmosphere. Weight of Ah-. Atmospheric Pressure; Ba- 

 rometer Changes in Atmospheric Pressure. Pumps. Compressed 

 Air.- 1 - Exercises. Collection of Gases. Discovery of Oxygen. 

 The Air a Mixture. Burning and Oxidation. Flames. Prepara- 

 tion of Oxygen. Properties of Oxygen. Oxygen and Life. Exer- 

 cises. How Nitrogen is Prepared, Properties of Nitrogen. Nitro- 

 gen and Life. Liquid Air. How the Atmosphere is Purified. 

 Summary. Exercises. 



CHAPTER IV. 



Heat 59 



Heat and Matter. Thermometers. The Two Thermometer 

 Scales. Heat and Temperature. Ways of Distributing Heat. 

 Radiation. Convection. Exercises. Physical States of Matter; 

 Solids. Liquids. Gases. Kindling Temperature. The Measur- 

 ing of Heat. Heat and Life. Clothing. Sources of Heat. Sum- 

 mary. Exercises. 



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