THE SOIL. 319 



If 3 inches deep, it is worth 38 I If 8 inches deep, it is worth 58 



4 " " ' " 42 9 " " " " 62 



5 " " " " 46 10 " " " " 66 

 fi " " " " 50 11 " " " " 70 

 7 " " " " 54 I 12 " u " " 74 



Hence each farmer may make an estimate for himself, 

 with regard to every variety of his soil, whether the cost of 

 increasing its depth will equal or exceed its value after the 

 task is performed. 



This, of course, supposes that the soil is of the same quality 

 throughout its whole depth, and it refers only to its chemi- 

 cal composition. Thefll are other considerations which 

 make the depth of the soil more important even than the 

 above table will indicate. If a soil is equally rich through- 

 out its whole depth, it would be of more than double value 

 if of double depth ; for its ability to withstand drought, and 

 its great capacity to absorb the water of heavy rains (with- 

 out being made too wet) would made it better, irrespective 

 of the elements of fertility that it might contain. Then 

 again, some soils which are of apparently no value may be 

 made quite fertile by being ploughed a little deeper than 

 has been done. 



TABLE, showing the weight per cubic foot of the different 

 kinds of earth. 



Clay 135 Ibs. 



Loose earth or sand 95 Ibs. 



Common soil 124 " 



Strong soil 1 27 



Clay and stones 160 



Brick.. . 125 " 



Chalk 174 ' 



NOTE. 23 cubic feet of sand, 18 cubic feet of earth, or 

 17 cubic feet of clay, make a ton. Eighteen cubic feet of 



