ESSENTIAL PARTS OF A PLOUGH. 15 



other parts of the plough could be screwed to it, or un- 

 screwed, and the certainty that the frame could always 

 be procured of exactly the same size and shape. This 

 last particular is of much consequence, for with wooden 

 ploughs it is very difficult to get two that will work ex- 

 actly alike, even if made by the same person. One may 

 work easily and well, and the other be very inferior, 

 although to the eye there appear no difference between 

 the two. The old wooden plough, however, is still in 

 use in many parts of the country. 



The lower part of this frame is called the sole of the 

 plough, and to the front part of it is attached the share, 

 which is a sharp instrument cutting in a horizontal 

 direction the slice of earth which is to be turned over. 

 The share gradually widens from the point to what is 

 called the Jin. It was formerly made of wrcmght iron, 

 but cast-iron shares are now generally employed. At 

 first these were found to wear away too fast on the 

 under-side, thus becoming blunt and inefficient. This 

 was remedied in a very ingenious way : the under-part 

 of the share was case-hardened to the thickness of one- 

 sixteenth, or one-eighth of an inch ; this hardened sur- 

 face would not, of course, wear away so quickly as the 

 rest, and thus by the natural wear of the upper part of 



PLOUGH-SHARES. 



the share constantly going on, a sharp edge was always 

 produced on the under-side. The ploughman using 

 this share is not, therefore, hindered with the frequent 

 sharpenings necessary for wrought-iron shares. 



