On the Draught of Ploi/ghs. 13 



as a saving to that amount in horse-keep. Where the ploughing 

 can be brought within tlie power of one horse this saving is 

 doubled ; and in four-horse work the proportion of course is 

 reduced to 2^ per cent. This will serve to give some idea of 

 the saving effected by any amount of gain in the draught of 

 ploughs ; but as I must proceed with my observations on our 

 experiment, I will reserve calculations to a future time. 



The intermediate draughts (2, o, and 4 in the table) will speak 

 for themselves. I will only express my strong doubts of the 

 actual advantage derived from any shapes tliat cause such an 

 excess of draught. This excess is occasioned in a considerable 

 degree, as I imagine, by the full breast, which presents a greater 

 resistance; and it is used because in adhesive soils in a certain 

 state they accumulate the mould upon them in a less degree. 

 It is yet to be decided whether this advantage is not obtained 

 at too great a sacrifice of horse-strength. 



1 tried D P again with a pair of horses for the purpose both of 

 comparing it with the double plough, and seeing what the addition 

 of the double whipper-tackle would have upon the draught ; and 

 I found this latter caused an increase of a sttme— and thus much 

 of saving in favour of one horse in a plough. 



There could not be a more conclusive trial of the respective 

 draughts of double and single ploughs than was made in the 

 above experiment. Messrs. Barrett's very complete double 

 plough is simply two D P's combined, the mould-boards, &c. 

 being the same casting. The very equal result shows in the first 

 place its careful construction ; and the uniform working of both 

 ploughs, whether single or combined, which was exhibited in 

 other trials as well as the above, was a satisfactory proof of the 

 correctness of the trials and of the soundness of the method of 

 test. And again, this uniform result, namely, that the draught 

 of the double was found almost always twice that of the single, 

 supplies data on which to found a correct estimate of the merits 

 and value of a double plough. 



The result of this and other little trials left no doubt which 

 was the fitter plough for competition at the Annual Meeting at 

 Liverpool. D P was there entered for trial as a one-horse 

 plough, and, by the prize it obtained, was adjudged to be the 

 lightest in draught of all the ploughs there brought forward. 



During the winter it was constantly at v/ork with L 2 ; and 

 when I occasionally tested it with the draught-gauge, I always 

 found it, as I had done before, more than 2 stones lighter. And 

 on one occasion, when they were ploughing a good gravelly loam 

 to the depth of 7 inches, I found L 2 working at a draught of 22^, 

 and D P at 18 stones. 



Experiment II. — The trial you heard of and requested for the 



