tHE PLOUGH. 209 



that it 19 expedient for the farmer to have tWn pieces of wcoci, 

 or slit-work, of different widths, at hand, to be placed on the 

 top of the harrow, with holes, through which the teeth may 

 fee placed, to prevent their penetrating deeper than the condi- 

 tion of the soil, or the nature of the crop may require. 



The Plougu, 



We are indebted to the proper and efficacious use of the 

 plough, for the advantages of agricultural science, and the 

 blessings of civil life. A knowledge, therefore, of its best 

 construction and management, is indispensable. There is in- 

 deed no other means of avoiding the errors and impositions of 

 visionary and speculating projects relating to this important 

 implement, but by adopting certain correct and practical prin- 

 ciples relating to it. 



The great points to be attended to in ploughing, are, 1, to 

 open a fair, regular furrow ; and 2, to do this with as little 

 resistance as possible. It has been believed that these advan- 

 tages may as well be obtained by the use of a plough to which 

 the mould board invented by Thomas Jefferson, is affixed ; the 

 following account of which, and of the principles upon which it 

 is constructed, are taken from a communication addressed to 

 Sir John Sinclair, in 1798, then President of the British Board 

 of Agriculture, and inserted in the Transactions of the American 

 Philosophical Society ,4th vol. "The mould board should be a 

 continuation of the wing of the plough-share, beginning at its 

 kinder edge, ^nd in the same place. Its first offic? is to receiv© 

 s 2 



