4H 



SCIENCE OF AGRICULTURE. 



Part II. 



diagonals, and for resisting the lateral or shaking motion occasioned by encountering 

 obstacles. (Quart Jour. Agr. vol. ii. p. 555.) The principal parts of harrows are 

 generally made of wood ; but they are frequently also constructed entirely of iron. 



2697. 



The Berwickshire harrow (Ji^ 



350 



350.) is the most perfect implement of the kind in 

 general use. It consists of two parts joined to- 

 gether by iron rods, having hasps and hooks. 

 Each part consists of four bars of wood technically 

 termed bulls, and connected together by an equal 

 number of cross bars of smaller dimensions mor- 

 tised through them. The former of these bars 

 may be 2^ inches in width by 3 inches in depth, 

 and the latter 2 inches in width by 1 inch in depth. 

 The longer bars areinclined at a certain angle to the 

 smaller, so as to form the figure of a rhomboid, and 

 they have inserted into them the teeth at equal dis- 

 tances from each other. This inclination of the 



longer bars is made to be such, that perpendicu- 

 !AiJ _^i^_^_^^_^_^_ __ [ ars f [om each of . t j je teetn) f a ii] n g U p 0U a ij ne 



drawn at right angles to the line of the harrow's motion, shall divide the space between each 

 bar into equal parts; so that the various teeth, when the instrument is moved forward, shall 

 equally indent the surface of the ground over which they pass. ( Quart. Jour. Jgr.) 

 2698. The angular-sided hinged hairoiv {Jig. 351.) is one of the best implements of 



351 , "f- 



the kind, as it both operates on the ground with great regularity, and is less liable to 

 ride or be deranged in turning, than the common, or the rhomboidal harrow. 



2699. The grass seed rhomboidal harrow (Jig.352.), is nothing more than the Ber- 

 wickshire harrow on a smaller scale. It is used chiefly for harrowing in clover and 

 grass seeds when sown among corn crops, or even alone. 

 352 



-£- 353 



i: 



Liib 



!!i lliiiiiiiii!'!! iiill 



i ! i : ' : ' 1 1 i : 1 1 ! i : 

 1 1 1 ■ ■ i . ■ ! I ! ! ; • • i ■ ' \ • ; ■ • ' 



2700. The common brake (Jig. 353.) is merely a harrow of the common kind, of 



