On Agricultural Mechanics. 119 



to a good tilth before the seed is sown; and the implement has not to 

 contend with any irregularity or roughness in the surface. 



There is one other point to be attended to in the construction of this 

 implement ; and that is, the joint or mode of connection between the two 

 portions of which it is composed. This joint should be such as to allow 

 of free and irregular motion in the two parts of the implement; at the 

 same time that it effectually hinders any chance of the one part becom- 

 ing interlocked with or riding, as it is termed, on the other. The 

 above figure represents a good description of joint; it allows of great 

 irregularity in the motion of the implement ; while the double joint in 

 the middle, with the chain at either end, hinders every chance of the 

 one part becoming interlocked with the other. 



5. The Grubber or Scarifier. 



The next implement we have to consider is the grubber or 

 cultivator. The action of this is somewhat similar in principle to 

 that of the harrow^ but it is much more perfect. Land is fre- 

 quently worked with this implement without the use of the plough 

 at all; and this perhaps is the most efficient way of cultivatirg 

 land off which turnips have been eaten, and preparing it for the 

 barley-seed. The manure left on the ground by the sheep thus 

 still remains near the surface ; it is not buried at the depth to 

 which it would be turned over^ had the land been cultivated by 

 the plough as deep as it is by the grubber. There is no imple- 

 ment whose action leaves the ground in such a healihy state as 

 this. The teeth tend to clear off weeds, and at the same time to 

 lift and loosen the soil in the most perfect manner. 



The first grubber of any note, though before that there had been many 

 an implement of the kind employed, was Finlayson's. It consists of a 

 frame-work which is supported by three wheels, one in front and two be- 

 hind. In this frame-work there are two rows of teeth ; the hindmost row 

 has one more than the front row; and the front teeth are placed opposite 

 the centres of the spaces between those behind them. The consequence 

 of this is, that, while the distance between two teeth in any one of the 

 rows is 1 foot, yet the distance between any two adjacent paths of the 

 teeth through the ground is only 6 inches, for the paths of the front teeth 

 lie between those of those behind. The frame ^s raised or lowered by 

 means of a lever, which acts on the projecting-bar or crank by which the 

 front wheel is attached to the frame, and gives it a less or a greater degree 

 of inclination ; thus letting the machine into the ground or raising it out. 

 This lever is managed by the driver behind the machine. There is, 

 however, no simple means of raising the back part of this machine. It 

 is necessary to fix on the depth you are to work it before you commence 

 w^ork in the day, and set the implement accordingly. The means of 

 doing this consists of a pierced vertical bar which connects the frame- 

 work with each of the wheels, and to which the frame-work is attached 

 by means of a pin. If it be too high, the pin must be lowered; and 

 vies versa. 



