38 Report on Trials of Plows. 



marked ou the figure in elevation, along the upper edge of the 

 beam and handle; but the chief points in height are repeated 

 here, the whole of them being measured from the base line 

 to the upper edge of the beam and handles at the respective 

 points. At the left handle, A, the height is three feet, at the 

 light handle, D, two feet nine inches; and a like difference in the 

 height of the two is preserved till the right handle approaches 

 the body at the middle stretcher, F; thence the difference increases 

 till it reaches the body. The height at the point of the beam 

 is eighteen inches, and the centre of the draught bolt, at amediuni, 

 seventeen inches. The lower edge of the mould-board behind, 

 of this plow at T, is usually set about half an inch above the base 

 line, and at the junction with the share about the same height. 



The dimensions in breadth^ from the land side line, embrace the 

 o1)liquity that is given to the direction of the beam and handles, 

 compared with the land side plane of the body taken at the sole. 

 The amount of obliquity, as exhibited by the dotted line, A C, 

 Fig. 50, which coincides with the land side plane of the body, 

 is that the axis of the beam at the extremity C stands one and a 

 quarter inches to the right, and, at the opposite end, the left 

 handle. A, stands about two inches to the left of the line. These 

 points may, however, be raised slightly from the dimensions here 

 given. In the first — the point of the beam — it is found in the 

 practice of different makers to range from one to two inches. 



The dimensions of the parts of the frame work of the plow 

 are: The beam, at its junction with the mould-board at M, is from 

 two and a half to two and three-quarter inches in depth, by one 

 inch in breadth — the same strength being preserved onward to 

 the coulter box, K. From the last point a diminution in breadth 

 and depth begins, which is carried on to the extremity, c, Avhei-e 

 the beam has a depth of one and three-quarter inches, and a breadth 

 of one-half to five-eighths of an inch. 



The coulter box is formed Ijy piercing an oblong mortise throngh 

 2 he bar, which has been previously forged with a protuberance at 

 this place, on each side and at the upper edge; the mortise is two 

 and one-half inches I)y three-quarters of an inch. 



From the junctioji with the mould-boar«l at IM, backward, the 

 beam decreases gradnally till, at the hind palm of the body at B, 

 it is two inches in depth and five-eighths of an inch in breadth 

 where it merges in the left handle, A. This last member retains 

 a nearly nnifoim size thioiighoul of two inches by three-eiijhths 



