I. ] CLASSIF1CA TION OF SOILS. 1 3 



19. The sand and clay are afterwards carefully dried 

 and weighed. If you found the weight of sand equal 

 to the weight of clay, this would represent, in other 

 words, 50 per cent, of sand. A soil of this composition 

 is known as a Loam, as shown in the following 

 table : 



It is necessary, however, to arrange for other pro- 

 portions of clay and sand, and these are distinguished 

 as Sandy loams and Clay loams. They take 

 intermediate position between the loam and the two 

 primary soils, sand and clay, and the table of classifi- 

 cation thus becomes more extended 



20. If, in the experiment indicated above, the soil 

 had contained more sand say from 60 to 80 per 

 cent, of sand it would then have been classified as a 

 sandy loam. If there had been less sand and more 

 clay say from 20 to 40 per cent, of sand then the 

 soil would then have been classified as a clay loam. 

 These groups of soils are based upon the percentage 

 of sand, and the residue in each case represents the 

 proportion of clay. It will be observed that soils 

 are grouped together, having a moderate variation 



