140 MECHANICS. 



ing a narrow slit left by the coulter. It is dragged for- 

 ward by means of a chain and capstan worked by a horse, 

 the machine itself being fixed with strong iron anchors. 

 This mode of draining is only adapted to clay soil, free 

 from stone, and although cheaply performed, has been little 

 used since the introduction of tile-draining. 



APPENDAGES TO THE PLOW. 



Wheel Coulters. In soils free from stones and coarse 

 gravel, and especially on the Western prairies, wheel 

 coulters are found to answer a good purpose, cutting 

 through the turf and roots of grass Avith great ease, and 

 making a smoother slice than the common cutter. But 

 where stones and other obstructions exist, it is necessary 

 to use the simpler, single blade coulter. A good repre- 

 sentation of the wheel coulter is seen on the figure of the 

 JVIoline Plow, on an early page of this chapter. 



Weed-Hook and Chain. In turning under large 

 weeds, grass, or other tall vegetable growth, two modes 

 are adopted. One is Fjg. 143. 



the use of the weed 

 hook represented in 

 the annexed cut ; 

 and the other is that 

 of a chain. The 

 weed-hook has been 

 long known, and is 

 made in various Weeci-hook. 



forms. Sometimes it is bent in the form of a bow 

 with the lower point projecting forward, as in the upper 

 figure; another form is like that shown in the lower cut, 

 pointing backwards. Tliis is less liable to be caught by 

 obstructions. The weed-hook operates on the principle 

 of bending the tall growth forward and prostrate, so that 

 the turning sod completely buries it. The same object is 



