CONTENTS 



Section Page 



1. Time of Sunrise and Sunset , . ,. . 1 



2. Experiments . . , . . 1 



3. Direction. The North V . . . . 2 



4. Circular Measurement . . . . . 7 



5. Other Directions . . . ... 8 



6. The Direction of Sunrise and Sunset . .. 10 



7. Telling Time by the Sun . . ' '*' . 12 



8. Other Ways of Telling Time .< '.- . 13 



9. The Height of the Sun at Noon * . \ 15 



10. The Light We Receive from the Sun . . 19 



11. The Sunlight Makes Plants Green ."'.. . .\ 20 



12. Other Changes of Color which are Caused by 



Sunlight . . . .. .' .'. . 22 



13. The Sunlight Good for Plants and Animals 25 



14. Light Travels in Straight Lines 'if- * . 26 



15. The Reflection of Light . . . . 29 



16. Light from Sources Other Than the Sun . 33 



17. The Heat we Receive from the Sun . . 39 



18. Expansion Due to Heat . . .44 



19. The Thermometer an Application of Expansion 48 



20. Heat Produces Light . . ' . . . 53 



21. Heat from Friction . . . / , 54 



22. Heat from Combustion . * . . 58 



23. Combustibles and Fuels . . . . 60 



24. Flames ^ . . . . . . . 62 



25. First Aid to the Burned . . . t . 64 



26. Conduction of Heat 66 



