Apart from the intrinsic values of the soils from a chemical' point of view, they grade mechanically by easy stages from sand to clav. The sand, although largely of quartz, has a fair proportion of felspar, together with a considerable quantity of aeolian dust, hence its productive but not lasting qualities under irrigation. The ordinary red soils are a mixture of sand and. clay, matured by oxidation, and with their amIJle percentage of lime form, when properly cultivated, an excellent

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... on. for agricultural and horticultural purposes. The grey soils· are exceedingly rich in plant foods, but are so compacted and: dif£.cult to cultivate that time and continuous tillage are neces-· sary to produce satisfactory results, which, however. when onceestablished, are lasting.