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SCIENCE OE AGRICULTURE. 



Part IE 



2704. Gray's teed-fiarrow for wet weather [Jig. 356".) promises to be useful in certain 



situations, as in a tenacious re- 

 tentive soil and moist climate. 

 The sowing of wheat, under 



existing circumstances, is one 

 of the most important brandies 

 of the corn farmer's labour. In 

 some backward seasons, it is 

 almost impossible to get wheat 

 land harrowed according to the 

 common method, especially 

 land that has been reduced by 

 3 summer fallow, without sub- 

 jecting it to poaching from the 

 horses, which is not only un- 

 favourable to the soil, but also 

 occasions a great waste of seed. 

 Hence it often happens, that a 

 less quantity of grain is got 

 sown than was intended, or is 

 requisite for the supply of the market. The beam (a) to which the harrows are attached 

 admits of being made shorter or longer as the width of the ridge requires ; the shafts 

 have freedom to turn round either to the right hand or to the left, and the teeth of the 



(harrows are placed square in the bulls, so that 

 they can be drawn from either end at plea- 

 sure. The wheels {Jig. 357.) may be from 

 three to four feet in diameter if made on 

 purpose ; but for the professional farmer it 

 will be sufficient to borrow a pair from a one- 

 horse cart. 



2705. The bush harrow (Jig. 358.) is used for harrowing grass lands to disperse 

 roughnesses and decaying matter ; and it is also sometimes used for covering grass or 

 clover seeds. Small rigid branches of spray are interwoven in a frame, consisting of 



358 



'H Ml' 



three or more cross bars, fixed into two end-pieces in such a manner as to be very 

 rough and bushy underneath. To the extremities of the frame before are some- 

 times attached two wheels, about twelve inches in diameter, upon which it moves ; 

 sometimes, however, wheels are not employed, but the whole rough surface is applied to, 

 and dragged on, the ground. 



2706. The only essential implement of the harrow kind is the Berwickshire harrow. 

 (Jig. 350.) 



Sect. IV. Hollers. 



2707. The roller is constructed of wood, stone, or cast iron, according to convenience 

 or the purposes for which it is to be used. For tillage lands, the roller is used to break 

 the lumps of earth, and in some cases to press in and firm the ground about newly sown 

 seed ; on grass lands it is used to compress and smooth the surface, and render it better 

 adapted for mowing. It has been matter of dispute whether rollers with large or small 

 diameters have the advantage in point of effect upon the land. In constructing heavy 

 rollers, they should not have too great a diameter, whatever the material be of which 

 they are formed, as the pressure is diminished where the implement is of very large size, 

 by its resting on too much surface at once, except an addition of weight in proportion 

 be made. By having the roller made small, when loaded to the same weight, a much 

 greater effect will be produced, and a considerable saving of expense be made in the 

 construction of the implement. The common length of tollers is five or six feet, and 

 the ordinary diameter from fifteen to thirty inches ; but those employed for flattening 



