e solution to dryness.

Out-of-doors.

23. Describe the appearance of the soil in the flower beds (_a_) during
hard frost, (_b_) in the thaw which follows a hard frost, (_c_) after
an April shower, (_d_) in drought at the end of summer, (_e_) in damp
October weather when the leaves are beginning to fall.

24. Is the soil equally friable at different times of the year?

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25. In what way do dead leaves get carried into the soil?

26. Can you find the worm holes in a garden lawn? in a garden path?

27. Take a flower bed or grass plot of small but known area (say 3
yards by 2 yards) and a watering can of known capacity (say 3 gallons).
Find how much water must be added to the soil before some of the water
will remain on the surface. What has been the capacity of the soil in
gallons per square yard?

28. Take two thermometers. Lay one on the soil, the other with its
bulb 3 inches deep in the soil. Compare their temperatures at morning,
noon and night.

29. Find from the 25-inch Ordnance map the reference numbers of the
fields near your school. Make a list of the fields, showing for what
crop or purpose each field is being used.

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INDEX

Acid waters, 40
Air in soil, 16, 70, 95

Bars in estuaries, 122
Black soils, 36
Blowing sands, 22
Bricks, 10, 16-18

Chalk, 26, 96
Chalk soils, 110-112
Clay, 6, 9-21
Clay soils, 75, 100-102
Cliffs, 116-119

Darwin's experiments, 11, 56
Deltas, 122
Drainage, 19, 96
Dwellers in the soil, 53-63

Earthworms, 54-56
Error of experiment, 48

Fallow, 14, 95
Fens, 112
Flora, 114
Fords, 126
Frost, action of, on soil, 83

Grassland, 75
Grit, 6

Hales's experiment, 73
Heaths, 104
Heavy soils, 100
Hoeing, 86-93
Humus, 36, 51, 93, 125
Hypotheses, 36

Land slips, 12
Leaf mould, 33
Light soils, 104
Lime, action of, on clay and soil, 19-21, 96-98
Lime water, 19
Loams, 2, 65, 108

Marsh gas, 40
Micro-organisms, 56-62
Moorland, 80
Mulch, 87, 90

Peat, 37-40, 130
Peat bogs, overflow of, 38
Perspiration of plants, 74
Plant food, 41-52, 62
Plant requirements, 64
Ploughing, 82
Pot experiments, 41-52, 54, 69, 71

Roads, 30-32, 101-112
Rolling the soil, 84

Sand, 6, 22-32, 41
Sand dunes, 22
Sandy soils, 68-72, 102-108
Shrinkage of clay, 10
Silt, 7
Soil sampler, 82, 88
Sowing seed, 84
Springs, 24-31, 111
Subsoi