CONTENTS

CHAPTER PAGE
1. Gravitation [1]
1. A real place where things weigh nothing and where there is no up or down [1]
2. "Water seeks its own level" [6]
3. The sea of compressed air in which we live: Air pressure [10]
4. Sinking and floating: Displacement [23]
5. How things are kept from toppling over: Stability [29]
2. Molecular Attraction [36]
6. How liquids are absorbed: Capillary attraction [36]
7. How things stick to one another: Adhesion [41]
8. The force that makes a thing hold together: Cohesion [44]
9. Friction [49]
3. Conservation of Energy [57]
10. Levers [57]
11. Inertia [66]
12. Centrifugal force [72]
13. Action and reaction [77]
14. Elasticity [82]
4. Heat [88]
15. Heat makes things expand [88]
16. Cooling from expansion [94]
17. Freezing and melting [96]
18. Evaporation [100]
19. Boiling and condensing [107]
20. Conduction of heat and convection [116]
5. Radiant Heat and Light [122]
21. How heat gets here from the sun; why things glow when they become very hot [122]
22. Reflection [129]
23. The bending of light: Refraction [136]
24. Focus [142]
25. Magnification [150]
26. Scattering of light: Diffusion of light [158]
27. Color [161]
6. Sound [174]
28. What sound is [174]
29. Echoes [183]
30. Pitch [185]
7. Magnetism and Electricity [190]
31. Magnets; the compass [190]
32. Static electricity [196]
8. Electricity [203]
33. Making electricity flow [203]
34. Conduction of electricity [213]
35. Complete circuits [219]
36. Grounded circuits [225]
37. Resistance [229]
38. The electric arc [233]
39. Short circuits and fuses [240]
40. Electromagnets [247]
9. Mingling of Molecules [259]
41. Solutions and emulsions [259]
42. Crystals [265]
43. Diffusion [268]
44. Clouds, rain, and dew: Humidity [274]
45. Softening due to oil or water [290]
10. Chemical Change and Energy [293]
46. What things are made of: Elements [293]
47. Burning: Oxidation [312]
48. Chemical change caused by heat [323]
49. Chemical change caused by light [326]
50. Chemical change caused by electricity [335]
51. Chemical change releases energy [340]
52. Explosions [342]
11. Solution and Chemical Action [349]
53. Chemical change helped by solution [349]
54. Acids [351]
55. Bases [355]
56. Neutralization [360]
57. Effervescence [365]
12. Analysis [370]
58. Analysis [370]
Appendixes:
A. The Electrical Apparatus [379]
B. Construction of the Cigar-box Telegraph [381]
Index [383]