3G0 SCREW ADJUStlNti VLOtjfen. 



farilier tcsti- Certificates were received from the following persons : viz, 

 Mr. Robert Wright, of Great Snoring, stating, that he has 

 three of Mr. Ball's ploughs, which he conceives to be much 

 superior to the common plough, both in the execution of 

 the work and easiness of draught, 



Mr. Mark Barret, farming steward to Sir George Chad, 

 stating that he has three of Mr. Ball's ploughs; that they 

 are the best he has ever made use of, and answer every pur- 

 pose, both as a swing and wheel-plough. 



Mr. Thomas Hurreil, of Saxlingharn, stating his opinion, 

 that Mr. Ball's plough will come into extensive use, being 

 an excellent plough for general purposes. 



Mr. Henry May Waller, farming steward to Sir Jacob 



Henry Astley, Bart., stating, that he has two of Mr, Ball's 



ploughs in constant use ; that he thinks them well calculated 



, for strong work ; and that they may be converted into a 



,. swing-plough, by disengaging the wheels. 



«» 



Rffsrence to (he Drawing of Mr, Bail's Plough, fig, 1, 

 P/. VIII. 



D?^;crrition of ^ ^^ the beam of the plough carrying the coulter B, 

 the piougb. share D, and handle E ; F is the mould board ; the draught 

 of the plough is taken by two iron rods G, connected at 

 one end with a hook a in the beam A ; and at the other 

 with an iron bridle H by a swivel-bolt; this iron bridle 

 has several notches to receive the draught-chain I, by 

 means of which the point of traction is adjusted sideways; 

 the adjustment for height, and in which the improvement 

 consists, is made by an iron frame K, at the top of which 

 a nut is placed acting upon a screw d fixed into the beam A; 

 the axletree e of the wheels J'f is connected with the iron 

 rods G, by a single bolt or pivot projecting from the end of 

 them, which passes through the axletree; by these rowans 

 the wheels always apply themselves to the inequalities of the 

 ground without iniluencing the motion of the plough. The 

 nut of the screw d, being turned, raises or lowers the iron 

 rods G, and elevates or depresses the point of traction, so 

 ;^hat the plough will cut a greater or leas depth of furrow. 



XI. 



