PENDIX . . . . . . . . . . . . . . . . . . . . . . 128
INDEX . . . . . . . . . . . . . . . . . . . . . . . 132

[Transcriber's note: The page numbers below are those in the original
book. However, in this e-book, to avoid the splitting of paragraphs,
the illustrations may have been moved to the page preceding or
following.]

LIST OF ILLUSTRATIONS

FIGURE PAGE

1. Soil and subsoil in St George's School garden . . . . 2

2. Columns showing what 100 parts of soil and subsoil
were made of . . . . . . . . . . . . . . . . . . . . 4

3. Columns showing what 100 parts of dried soil and
subsoil were made of . . . . . . . . . . . . . . . . 8

4. Clay shrinks when it dries . . . . . . . . . . . . . . 11

5. Clay swells up when it is placed in water . . . . . . 12

6. Landslip in the Isle of Wight.
_Phot._ Valentine & Son . . . . . . . . . . . . . . 13

7. Clay does not let water run through . . . . . . . . . 14

8. Sand allows air to pass through but clay does not . . 15

9. A brick allows both air and water to pass through it 17

10. Lime added to turbid clay water soon makes the clay
settle . . . . . . . . . . . . . . . . . . . . . . . 20

11. Sand dunes, Penhale, Cornwall.
_Phot._ Geological Survey . . . . . . . . . . . . . 23

12. Blowing sand covering up meadows and ruining them.
_Phot._ Geological Survey . . . . . . . . . . . . . 25

13. Model of a spring . . . . . . . . . . . . . . . . . . 26

14. Foot of chalk hill at Harpenden where a spring breaks
out. _Phot._ Lionel Armstrong . . . . . . . . . . . 27

15. The little pool and the spring.
_Phot._ Lionel Armstrong . . . . . . . . . . . . . . 28

16. Water spouting up from a bore hole, Old Cateriag
Quarry, Dunbar. _Phot._ Geological Survey . . . . . 29

17. Sandy soils in wet and in dry positions . . . . . . . 31

18. Map of the roads round Wye . . . . . . . . . . . . . . 32

19. Peat bog in Hoy, Orkney: peat is being cut for fuel.
_Phot._ Valentine & Son . . . . . . . . . . . . . . 39

20. Rye growing in surface soil, subsoil, and sand . . . . 42

21. Mustard growing in surface soil, subsoil, and sand . . 43

22. Mustard growing in soil previously cropped with rye,
and in so