1922.] The Shrawardine Tractor Trials, 1921. 



973 



THE SHRAWARDINE TRACTOR 

 TRIALS, 1921. 



Thompson Close, B. J. Owen, B.Sc., B.Eng., etc., and 

 H. G. Richardson, M.A., B.Sc. 

 Ministry of Agriculture and Fisheries. 



The Tractor Trials conducted at Shrawardine from the 19th 

 to the 24th September last were arranged by the Society of Motor 

 Manufacturers and Traders and were conducted on the same 

 basis as those held by the same society in 1919.* There was 

 therefore no attempt made, as at the trials organised last year 

 jointly with the Royal Agricultural Society, to place the tractors 

 in any order of merit,! but the object was to state the actual 

 results achieved by each machine entered. The report was 

 issued very soon after the conclusion of the trials, having regard 

 to the amount of work involved in the compilation of the tables, 

 and in this as in other respects the trials reflect great credit on 

 the organisers. 



The area chosen for the trial ground was admirably .suited to 

 the purpose, and although it was somewhat difficult of access, 

 this is a drawback almost inseparable from trials or demonstra- 

 tions of any size. The total area of about 500 acres was divided 

 between 25 fields all within comparatively easy reach of Shrawar- 

 dine station and the headquarter' s offices. The soil varied from 

 medium to heavy four-horse land, and only in one or two fields 

 was it really light. The programme was so arranged as to permit 

 all the tractors entered to be at work every day and all day, and 

 there was very little idle time anywhere. A special effort had been 

 made to record the performances of each machine as accurately 

 as possible : and while improvements might be conceivable in 

 points of detail it can fairly be said that the trials were con- 

 ducted under as favourable conditions and with as efficient an 

 organisation as it is reasonable to expect. 



For recording some of the main factors in the work actually 

 performed by the machines, Watson dynamometers were em- 

 ployed, designed by the Consulting Engineer of the Society. 

 The instruments were calibrated at the National Physical Labora- 

 tory. The dynamometers are designed to record graphically 

 the draw-bar pull, the distance travelled, the time occupied and 



* See this Journal, October, 1919. 

 i Ibid, November, 1920. 



