SITUATION AND SOIL 55 



parched, the experienced gardener knows that it holds a 

 quantity of what is called film water. On heating a little of 

 the earth in a test tube, the glass becomes lined with tiny 

 droplets that have been driven off from the apparently dry 

 earth. To verify one's conclusions and to get further advice, 

 a sample may be sent for analysis to the state experiment 

 station. Owing to the small quantity under inspection, how- 

 ever, this method often fails to give satisfactory results. 



Another matter for consideration is to what extent various 

 soils retain the rain. For testing this some simple scheme 

 can be devised to show at what rate water will percolate 

 through the different materials. A good way is to set up sev- 

 eral lamp chimneys, putting a sample of earth in each, noting 

 how the different samples behave when watered. A sandy 

 soil, it will be seen, allows the water to filter through in almost 

 no time. A clay soil, on the contrary, drains very slowly, some- 

 times scarcely at all. Picture this on a grand scale and you 

 have before you exactly what happens to the rainfall on a 

 farm. In the first case the sandy earth would be left in a 

 chronic state of drought, while in the second the water would 

 settle in puddles. To take " any old soil " and mix into it 

 the ingredients necessary to make it fit for all-round garden 

 purposes requires good sense and no little skill. Of course, 

 where there is really no true soil foundation, but only a waste 

 of bricks and rubbish, the problem is even more difficult, since 

 in that case a garden is not merely made but built. In the 

 case, too, of hopelessly rough land the stumps and stones 

 will first have to be removed, perhaps by blasting. After- 

 wards the humps and hollows can be leveled by spreading 

 on a plentiful supply of loam, hauled by the cartload. 



The item of loam in the expense book need not be so 

 very great. Indeed, for school gardens enough loam of suffi- 

 cient richness may usually be obtained free of charge from 



