HARROWING. 



473 



The balks of the above set of harrows were made of wood, in 

 order to insure extraordinary lightness; but, for general purposes, 

 I prefer those made of iron, the weight of which can be increased 

 to any reasonable degree, without adding much to their sub 

 stance. This is important in working tenacious clays, which, 

 by adhering to the common clumsy wooden balks, considerably 

 increase the labor, and at the same time impede the proper 

 execution.&quot; 



Sometimes harrows are made in two parts, that is, two small 

 and complete harrows, placed side and side, and united by flex 

 ible hinges. In such case, the harrow can be reduced to half 

 its width, by one part being doubled over on the back of the 

 other ; or, when the land is in ridges, and the harrow travels on 

 the summit of the ridge, the two parts, by the flexible junction 

 in the centre, are able to accommodate themselves to the curva 

 ture of the ground upon which they travel. Sometimes three or 

 four harrows are attached first to each other, by these hinges, 

 side and side, arid then to a single beam, to the ends of which 

 the traces of the horses are appended, and in this case they 

 sweep a breadth of nine feet. This carries on the work with 

 great rapidity. A pair of good horses might carry such a breadth 

 without difficulty, upon light land ; but upon a heavy and tena 

 cious soil, the labor would be too great for them. 



&quot;Gang of Heavy Iron Harrows. 



&quot; The above engraving of iron harrows is introduced to show 

 the form in which they are usually made ; they are used in 



40* 



