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179- The subsoil stirrer or sub-soiler (Fig. 4) moves 

 the subsoil without turning it up.. This is also used behind 

 an ordinary plough. It has no mould-board and it can hardly 

 be called a plough. It moves the soil 12" to 18" deep. A 

 subsoil stirrer is sometimes attached to a strong wheel- 

 plough on the right side and in a line with the point of the 

 share. It passes along the bottom of the furrow raised and 

 moves it. A subsoil plough on wheels adapted for light 

 soils costs 7 guineas and for heavy soils 10 guineas. 



1 80. The Ridging or Double-mould-board plough (Fig. 2) 

 is made like a swing or a wheel plough. It has a mould-board 

 on either side, but no coulter. The mould-boards are shorter and 

 nearly flat. It is used for making ridges and splitting them, 

 also for splitting drills for sowing turnips, potatoes &c. A 

 marker is hinged on to the beam of the ridging plough. It 

 marks on the ground the line where the next ridge is to be. 

 The marker is held in position by a chain. By another chain 

 behind, the ploughman can turn the marker on either side of 

 the plough. The cost is 4 and i extra for wheels. 



181. The pulverising plough breaks up but does not turn 

 over furrows. The Indian plough and the Subsoiler may be 

 regarded as pulverising ploughs, and the improved ploughs 

 as simple swing-ploughs. 



182. The One-way-plough. With an ordinary plough 

 ploughing cannot be done line after line in succession, as the 

 slices are turned one way during the forward march and in 

 the opposite way during the return march. The whole of the 

 land cannot in this way be both ploughed and -turned over. 

 With the one-way-ploughs, of which one form is called the 

 Turn Wrest or Turn-Wrist plough, and another the Balance 

 Plough, furrow slices are all laid side by side one against ano- 

 ther in the same direction avoiding open unploughcd furrows 

 and ridges covered by furrow slices. There are two sets of 

 mould-boards and shares in the Balance Plough. When one 

 set is at work on one side, the other set is kept raised on 



