MECHANICS OP AGRICULTURE. 53 



laid against the preceding furrow from the end of the 



mould-board at 6. 



6 represents the surface, and 

 the course of movement of the 

 soil until it is turned over is 

 seen in the following sections 

 of the diagram. Next we have 

 the furrows laid up in regular 

 Moyiug tbe soil. order tor the reception of seed 



or for harrowing down for other 



crops. When grain is sown it falls into the angles between 



the furrows and is 



11 -i 'V / < \/'-X/v\/.X /.\ 



covered by passing har- /^ / ^.'' :: ^^<^' 

 rows over the land. '/^"J^\^^f^^'^ 

 which smooth down the 

 tops of the furrows. The 



movement Of horses and Section of Regularly Laid Furrow. 



men over the surface 



tend also to break down the furrows and close up the 

 spaces under them. The covered surface growth is thus 

 converted into manure for nourishing the young roots of 

 the crop. The process shows further how green manuring 

 (the growth of green crops for manure) enriches the land. 



By ploughing, we make the soil ready for seed and for 

 plants, and by after ploughing, shallow or deep as may be 

 required, the surface of the soil is kept loose and clean, and 

 in the best state for the growth of crops. The cultivator, 

 scarifier, grubber, and other implements drawn by animals 

 or by steam, are used for cultivating the land by pul- 

 verising it, killing weeds, &c. 



The plough, then, is a combination of the wedge, 

 screw, and lever, and just in proportion to the skill of the 

 maker in developing those principles in mechanics in the 

 plough, each in the right proportion, and of the right 

 material in the right place for the work to be done, those 

 features go to make the most suitable plough. But different 

 soils require differently arranged implements, whether the 

 work be breaking up new land, ploughing where stumps and 

 roots cannot l>e got rid of for a time then the stump- 

 jumping plough of South Australia is a l>oon ploughing 



