[12. The Sea-going Boat]

[13. The Cave]

[14. The Slab Found in the Cave]

[15. Old Coins Found in Cave]

[16. Cane Crusher]

[17. A Magnet]

[18. Magnetic Induction]

[19. The Two Magnets]

[20. Making a Permanent Magnet]

[21. Illustrating Wind Pressure, 1]