1920.] 



The Lincoln Tractor Trials, 1920. 



723 



for practical work. A suggested alternative is to classify by 

 weight, which would give a fair standard of comparison. 



The decision of the Eoyal Agricultural Society to require 

 the use of similar ploughs for identical tests has met with 

 considerable criticism, not, it may be suggested, without sub- 

 stance. It is understood that the object was to discover which 

 tractor did the greatest acreage on the least fuel with a given 

 kind of plough. The implied premise is surely a false one. 

 Power to plough two or more furrows, is no criterion of the capa- 

 city of a machine, for conditions vary with the same plough, 

 even with the same setting — if that is possible to obtain, which 

 is very doubtful. 



There seems no practical reason why all kinds of ploughs 

 should not be allowed. ]No tractor can be tested for efficiency 

 in ploughing if it has not a plough suited to it. As foreign 

 ploughs were excluded, some machines were handicapped; the 

 best results could not be obtained with the ploughs supplied, 

 and it is evident that the results are less valuable than they 

 would have been if every machine had the option of using 

 the plough to which it was best suited. Drawbar pull can be 

 stated in definite figures, and the capacity of the tractor thus 

 ascertained. It would be better if each machine were allowed 

 its own particular plough and if a lengthy dynamometer test, 

 giving definite figures, were adopted. The comparison would 

 be placed on a scientific and easily calculable basis. 



With regard to the actual ploughs used, it may be remarked 

 that they were efficient, although, as compared with American 

 types, on the heavy side. Considerable trouble was experienced 

 with the " self-lift " device, but this appeared to be due to 

 adjustment and not to weakness in design. The decision to 

 insist upon uniformity of type had the advantage of bringing 

 home to every spectator the need for further research in the 

 design of ploughs. It was shown without question that a 

 plough of the same design and setting will turn a very different 

 furrow at different speeds. 



The economical speed of mechanical traction is more than 

 double that of the horse, and the mould boards which will 

 need to be developed are those which vnW perform the work 

 with greater speed and equal excellence. To the disappoint- 

 ment of many tractor manufacturers, and to the loss of agri- 

 culture, plough designers have not yet put upon the market 

 implements which will take into account the requirements of 

 mechanical traction. Undoubtedly a great deal of patient 



