106 On Agricultural Mechanics. 



It not only stirs the subsoil, but opens the furrow in which the 

 subsoil-plough works. It consists in the attachment of a strong 

 tine, similar to those used in Biddel's scarifier, to the common 

 plough, in a position in which it acts after the furrow -slice has 

 been turned. 



[The Charlbury Subsoil Plough.] 



This implement, doing all the work, requires, according to an 

 experiment recorded there, less force to work it than the subsoil- 

 plough, doing only one portion of the operation. It cannot, how- 

 ever, be so efficient in thoroughly stirring the subsoil as the 

 original implement. The other attempt at diminishing the ex- 

 pense of subsoil ploughing is by Mr. Armstrong, of Sterlingshire, 

 for which he received premiums from the Sterlingshire Agricul- 

 tural Society and from the Highland Society. A description of 

 it was given by Mr. Smith, of Deanston, at an agricultural meet- 

 ing lately, which I transcribe. The inventor has adapted the 

 principle of Mr. Wilkie's turn-wrest plough to Smith's subsoil- 

 plough. 



" The general frame-work is that of a subsoil-plough rather 

 under the medium size, and to it is attached a hinged mould- 

 board, similar to the mould-board of Mr. Smith's hill-side or 

 turn- wrest plough. By means of this arrangement the plough 

 can be used for removing the furrow preceding the operation of 

 the subsoil -plough, and, when the furrow has been removed, the 

 mould-board being moved upon its hinges, from its working posi- 

 tion, rests over the beam of the plough, whilst the instrument is 

 used for subsoiling in the bottom of the furrow just removed. 

 Thus the operation of removing the furrow and subsoiling can be 

 alternately performed with the same implement, by the same 

 ploughman, and the same team of horses, l3y a simple movement 

 of the mould-board, which is done in an instant by the hand of 

 the ploughman at each turning. The additional weight of the 

 mould-board serves to keep down the plough whilst subsoiling in 

 difficult ground. The judges consider this implement well con- 

 trived, and as being an important boon to small farmers, and as 



