138 OPERATIONS OF TILLAGE. 



about when at A, he proceeds in the direction B E, and 

 so on, always turning left about, until he has arrived at the 

 middle space o, when the whole space A D and B E will 

 have been ploughed. 



" Sometimes, for convenience, and the saving of dis- 

 tance, he may plough in the first place round the central 

 line BE, by turning from left to right, and then plough 

 the remainder of the interval by turning from right to left. 



" These are matters of detail somewhat difficult to be 

 described clearly, but so simple in themselves that they 

 need only to be seen in the field, to be thoroughly under- 

 stood. 



" The first operation, we have seen, is, striking the 

 furrows previous to forming the ridges. This is done by 

 laying off, by means of furrows, first the lines of the head- 

 lands, and then the parallel lines corresponding to the fu- 

 ture centres of the ridges to be formed. 



" The next operation is forming the ridges. This is 

 done by beginning at the centre, and ploughing towards 

 it, until each ridge is formed. 



" When ridges are formed, they may. subsequently be 

 ploughed in different ways. 



" First, they may be gathered ; in which case, begin- 

 ning at the crown, the ridge is ploughed, and an increased 

 elevation given to it. 



" Second, they may be cast ; in which case, two ridges 

 are ploughed together, and either formed into one large 

 ridge, or, by keeping the open furrows clear, retained in 

 two ridges. 



" Third, they may be cloven ; in which case, begin- 

 ning at the open furrows, the half of each adjoining ridge 

 is laid together. The first two furrow-slices may either 

 be laid close together, or the open furrow may be kept 

 clear between them. In the first case, each ridge will 

 have been so cloven, that the open furrow shall have be- 

 come the crown, and the crown the open furrow. In 

 the second, each ridge will have been cloven into two, 

 and the number of ridges and open furrows doubled. 



" In the original laying out of the ridges, the lines 

 have been described as running straight through the field ; 



