232 Experimental Inquiry on Draught in Ploughing. 



The superiority of Hart's one-wheeled plough^ in lightness of 

 draught, over the two Scotch ploughs^ and indeed, more or less, 

 over all the others, continued, it will be seen, as before. That of 

 the FF, with wheels, over the same plough as a swing, did not 

 continue, but was reversed : the cause appeared to be, that both 

 its wheels were clogged with dirt, the land-wheel, though on a 

 tolerably firm surface, through its small size 5 the furrow- wheel, 

 though of course larger, from collecting the loose dirt in the 

 furrow. The same causes affected the Rutland plough, and I sup- 

 pose King's also, but I omitted to observe this plough at the time. 

 Hart's was exempted by its single wheel, of a better size, running 

 on the unploughed surface. The Scotch horses worked without 

 signs of distress on this ground. We next proceeded to a field 

 which had been selected by the occupier, a member of our So- 

 ciety, Mr. Brooks, of Lyford, as being peculiarly calculated to try 

 the powers of the pair of Scotch horses. 



Trial V. 



Much interest was attached to this trial, and several neighbour- 

 ing farmers had come to witness it. The surface of the soil is 

 more a clay than a loam, of moderate fertility, resting on a decided 

 clay, known to geologists as the Kimmeridge clay. We found in 

 the field four strong horses at work in line according to the gene- 

 ral practice, drawing an old Berkshire plough, and having evi- 

 dently enough, though not too much, to do. The draught- guage 

 when applied showed that in a 5-inch furrow they were exerting 

 a power of 4 cwt., or 32 stone, and in one of 6 inches, 2 stone 

 more, 34 stone. 



Furrow 5x9 6x9 

 Old Berks . . 32 . 34 



The next plough tried was Ferguson's, with its two horses, 

 which showed a draught of 3 cwt. only in the 5-inch furrow, 

 exactly one horse less. The state of the land, which was ex- 

 tremely wet from heavy rains, was very disadvantageous to the 

 pair of horses, since, though the ground was easier for the plough, 

 it was in a greater proportion difficult for the horse who was upon 

 the unploughed land, into which he sank four inches at every 

 step. One clear result, however, appeared already, that even if 

 2 horses abreast were not enough, 3 horses in line with Fergu- 

 son's plough would have exactly the same work to do as the 4 

 horses whom we found drawing the old Berkshire plough. 



[5x9 6x9 

 Ferguson . . . . 24 . 26 

 Clark . . . . 27 . 30 

 Hart . . » . 30 . 28 

 FF, swing ... 24 . 26 



