APPENDIX. 133 



the same way as this trenching by the spade. The increase of crops 

 in grounds thus managed has been always an ample compensation for 

 the labor. The loosening of the earth and the consequent removal of 

 the water and admission of the air, besides affording room for the ex- 

 pansion of the roots, without doubt by a chemical action, assists the 

 nourishment and growth of the plant. The great objection to deep 

 ploughing has always been, that the cold gravelly pan was brought to 

 the surface; the vegetable mould buried beneath it; and, that it requir- 

 ed a great length of time and an extravagant amount of manure, to 

 bring the land into a healthy and fruitful condition. These models 

 are copied from a late number of the British Farmer's Magazine; and 

 I subjoin the accounts which are therein given of them. 



" The most astonishing effects appear to have been produced by a 

 new agricultural implement, the invention of Mr. Smith of Deanster 

 near Sterling in Scotland, called the Subsoil Plough. This machine 

 is a necessary accompaniment to draining; but when that is done effec- 

 tively, it seems calculated to render the most sterile and unproductive 

 soil fertile and profitable. There is no difficulty more fatal to the 

 practical farmer than that of cultivating a thin shallow soil with a stiff 

 retentive subsoil. Whatever pains may be taken with the tillage of 

 the former, however expensive the dressing which may be used in its 

 cultivation, the nature of the subsoil will always counteract its benefi- 

 cial effects. Many persons have endeavored by trenching to obviate 

 this difficulty, but where the subsoil is of that sterile nature, and re- 

 quires exposure to the atmosphere for so long a period to make it pro- 

 duce, few farmers have been found bold enough to repeat the experi- 

 ment. Mr. Smith's ingenious invention, by breaking the subsoil with- 

 out bringing it to the surface, renders it pervious both to air and water. 

 The same chemical changes, which take place in a fallow, owing to 

 its exposure to the action of wind and rain, are thus brought into oper- 

 ation in the subsoil ; whilst the upper is in the ordinary course of crop- 

 ping, and when, after a few years by a greater depth of ploughing, the 

 subsoil is mixed with the upper, it is found to be so completely chang- 

 ed in its nature as to be capable of producing every species of grain. 

 The experiment has been tried for twelve years, and with uniform suc- 

 cess." 



