201 



The results detailed in the foregoing table may be summarised as fol- 

 lows: 



Pebbles Gravel Sand Silt Clay 



Xo. > 3 mm. 3 1mm. 1 -05mm. '05 -005mm. < -005 mm. 



It will be observed that the alkaline patch, which is also chemically 

 the poorest of the four in plant food, contains very much less silt than the 

 others, whereas No. 23, the soil best supplied with plant food, is likewise 

 the richest, in silt. 



In order to illustrate the character of these soils the better, a diagram 

 showing the texture curves of soil No. 24, for each eight inch section, 

 is appended. Such diagrams reveal to the eye, at a glance, more clearly 

 than mere figures can, how, on descending from surface to sub-soil, in No. 

 21, the sand diminishes in proportion, while the silt and clay increase; in 

 No. 22 sand also diminishes, while clay increases ; in No. 23 both sand and 

 clay diminish, but silt increases ; and in No. 24 the proportion of clay in- 

 creases, and there is a diminution of pebbles. 



On a former page reference was made to the Orange River clay col- 

 lected in the Prieska Division (No. 1, Prieska Division soils) : the chemical 

 analyses of sojls from farms situated along the river banks lower down were 

 also given (Nbs. 2, 3, and 4) : these three samples, in each case, represented 

 the surface soil to a depth of twelve inches, but opportunity was taken at 

 the same time to secure specimens of the subsoil to* a depth of three feet, 

 and mechanical analyses of all these were made, with the results stated 

 below : 



Pebbles Gravel Sand Silt Clay 



No. > 3 mm. 3 1mm. 1 '05mm. -05 -005mm. < '005 mm. 



1 nil nil -29 2S-53 71-18 



