CONTENTS 



Section Page 



1. Time of Sunrise and Sunset . ( . . 1 



2. Experiments . . 1 



3. Direction. The North , . . . . 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 . . .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 . . . . 64 



26. Conduction of Heat 66 



