PKEPAKATION OF THE SOIL, OR TILLAGE. 113 



has to overcome. The young weeds that are becoming 

 visible between the hnes are then gotten rid of. 



Various mechanical devices have been brought to 

 notice, and in many cases adopted, these working 

 principally when the young root is about two inches 

 in height. They are generally assisted by hand labor, 

 as it would be dangerous to the final crop to approach 

 within several inches. In Germany they prefer hand 

 labor, and we can only indorse their ideas, as the results 

 of the use of machinery brought to our notice were far 

 from being satisfactory. It is advisable to rid the soil 

 of the weeds by hand rather than with a hoe for the fii'st 

 ten days, as the slightest vibration produced upon the 

 ground in proximity to the final desired root might 

 result in considerable injury, whilst, on the contrary, 

 when the plant has attained the size shown in fig. 22, 

 the danger is over. 



The thinning out is the next operation. The methods 

 vary with the practice in sow^ing. When this is 

 broadcast the labor is greater than when in lines, as 

 in the first case the roots must be destroyed in such a 

 manner that a given distance will be left between the 

 various remaining plants, whilst in lines, the space be- 

 tween each is only to be considered. If the thinning 

 out be not done with care, the crop will be ruined. 

 Some reject the use of the hoe and advocate the knife, 

 only penetrating the ground to a sufiicient depth to 

 destroy all roots between the desired ones ; this is most 

 wise when the sowing has taken place in clusters or 



