Lessons on Soil | Page 3

. . . . . . . . . 66
31. Plants growing in soils supplied from below with water. All the water the plants get has to travel upwards 67
32. Mustard growing in soils supplied with varying quantities of water . . . . . . . . . . . . . . . . 69
33. Wheat growing in moist and in dry soils . . . . . . . 71
34 a and b. Plants found on a dry soil had narrow leaves, those on a moist soil had wider leaves. Phot. S. T. Parkinson . . . . . . . . . 72, 73
35. Plants give out water through their leaves . . . . . . 74
36. Stephen Hales's experiment in 1727 . . . . . . . . . . 75
37. Hill slope near Harpenden showing woodland at top and arable land lower down. Phot. Lionel Armstrong 77
38. View further along the valley; woodland and arable above, rough grassland near the river. Phot. Lionel Armstrong . . . . . . . . . . . . . . 79
39. Rough grass pasture near the river. Higher up is arable land. Phot. Lionel Armstrong . . . . . . . 81
40. After harvest the farmer breaks up his land with a plough and then leaves it alone until seed time. Phot. Lionel Armstrong . . . . . . . . . . . . . . 83
41. Rolling in mangold seed on the farm. Phot. H. B. Hutchinson . . . . . . . . . . . . . . 85
42. Soil sampler . . . . . . . . . . . . . . . . . . . . . 88
43. Cultivation and mulching reduce the loss of water from soils . . . . . . . . . . . . . . . . . . . . . 90
44 a and b. Maize cannot compete successfully with weeds . . . . . . . . . . . . . . . . . . . . 94, 95
45. A plot of wheat left untouched since 1882 at Rothamsted has now become a dense thicket. Phot. Lionel Armstrong . . . . . . . . . . . . . . 97
46. A badly drained wheat field . . . . . . . . . . . . . 99
47. Highly cultivated sandy soil in Kent . . . . . . . . . 103
48. A Surrey heath . . . . . . . . . . . . . . . . . . . . 105
49. Woodland and heather on high sandy land, Wimbledon Common. Phot. R. H. Carter . . . . . . . . . . . 107
50. Poor sandy soil in Surrey, partly cultivated but mainly wood and waste . . . . . . . . . . . . . . . . . . . 109
51. Open chalk cultivated country, Thanet . . . . . . . . 113
52. Cliffs at the seaside, Manorbier. Phot. Geological Survey . . . . . . . . . . . . . 117
53. Cliffs in inland district, Arthur's Seat, Edinburgh. Phot. Geological Survey . . . . . . . . . . . . . 119
54. Model of a stream . . . . . . . . . . . . . . . . . . 120
55. The bend of a river . . . . . . . . . . . . . . . . . 121
56. The winding river--the Stour at Wye. Phot. R. H. Carter . . . . . . . . . . . . . . . . 123
57. Sketch map showing why Godmersham and Wye arose where they did on the Stour . . . . . . . . . . . . 126
58. Ford at Coldharbour near Harpenden. Phot. Lionel Armstrong . . . . . . . . . . . . . . 127
The photographs of the pot experiments are by Mr Lionel Armstrong.

{xi}
INTRODUCTION
The following pages contain the substance of lessons given at the village school at Wye to the 4th, 5th, 6th and 7th standards (mixed) and at St George's School, Harpenden, to the 3rd form. There is, however, an important difference between the actual lessons and the book. The lessons had reference to the soils round about the village, and dealt mainly with local phenomena, general conclusions being only sparingly drawn; while in the book it has been necessary to throw the course into a more generalised form. The teacher in using the book will have to reverse the process,