Manor Farm, Braydon, TVilts. 383 



clay, to the bright red, or light-brown colour, which is character- 

 istic of well drained and properly aerated soils. 



The subsoil of the Braydon pasture-land is very stiff, lighter 

 coloured than the surface, here and there showing streaks of oxide 

 of iron, and containing some flints and silicious pebbles. 



An analysis of 100 parts gives of — 



Organic matter and water of combination ., .. 7*43 



Oxides of iron and alumina 19'28 



Lime '-ii) 



Magnesia "IS 



Potash 1-39 



Soda -M 



Phosphoric acid '14 



Sulphuric acid '08 



Insoluble silicious matter 7045 



100-00 



As we might expect, the subsoil contains much less organic 

 matter than the surface, and more oxide of iron and alumina, 

 though a close resemblance subsists between the two; on the 

 whole, the subsoil contains in large proportions the more valuable 

 constituents which occur in the ashes of plants. 



On comparing the chemical composition of the sterile pasture 

 with that of good clayland, its poverty — due to a general defici- 

 ency in all the elements of fertility — becomes apparent. Thus 

 the pasture is poor in phosphoric acid and in potash, and contains 

 scarcely any lime — unquestionably the most indispensable ash- 

 constituents of plants. The subsoil is not only much richer in 

 potash, phosphoric acid, and lime, but exhibits an appreciable 

 quantity of phosphoric acid. Still the general resemblance be- 

 tween the surface and subsoil is so great that we cannot doubt 

 that both were originally the same deposit, and that in the course 

 of time the surface has become exhausted in a great measure by 

 bad management. The inspection of the land, at various parts 

 of the fields where trial holes were dug and samples taken, gave 

 both clear indications of the causes of barrenness and of the 

 appropriate means of improving its productiveness. The most 

 superficial observer, walking on the spongy wet pasture at Bray- 

 don, would recojrnise deficient drainasre as one of the causes of 

 sterility. We have said that, notwithstanding the miserable ap- 

 pearance of the grass, a close examination of the soil revealed 

 the fact that there was a fair depth of surface-mould, then a not 

 impervious clay — as was evident by the occasional stains of per- 

 oxide of iron. Beneath this was found generally a really stiff 

 clay, uniform and innocent of water — apparently impenetrable. 

 The theorists may smile with incredulity, yet such is the fact, for 

 we have proved it ; and this is one of the lessons we learnt at 

 Braydon, and a lesson that some of our engineers might con over 



VOL. II.— S. S. 2 C 



