1920.] 



The Lincoln Tractor Trlu.s, 1920. 



715 



tion, although it is possible to divide the whole of classes 1, 2^ 

 3 aud 7 into two main types: — 



(a) Those in which the whole of the machinery is built 



up in one block of casting, i.e., there is no frame; 



(h) Those in which there are separate units on a frame- 

 Broadly speaking, very little difference was observed between 

 the machines which competed this year and last year. It 

 would seem as if for the time being the manufacturers regard 

 design as having reached finality, and are content with minor 

 improvements. In this connection it may be remarked that 

 manufacturers and designers have naturally been strongly 

 influenced by the example of horse ploughing, and have 

 regarded the tractor as a substitute for the horse. This, and 

 the fact that the motor car and tractor industries are closely 

 linked, may have led to the neglect of the possibilities of the 

 conversion of power into rotary motion; the problem is 

 engaging the attention of French manufa-cturers and will 

 require close investigation in this country. It is one, how- 

 ever, in which the question of the act of cultivation cannot 

 be separated from the question of the tractor, a point to which 

 reference is made later. 



Weight in Relation to Horse-power. — In the more recent 

 designs of tractor there has been a tendency to reduce weight 

 per horse-power, and it was worth noting that the Fordson 

 Tractor — the lightest of all — is only 1 cwt. per horse-power, as 

 compared with 3 and 4 cwt. per horse-power in the case of 

 heavier machines. It is evident, however, that the whole 

 question of weight in relation to horse-power is at present 

 little understood. Weight per horse-power should be, and 

 undoubtedly will be, universally regarded as a necessary 

 element in the selection of a machine for any particular class 

 of work, and though this factor is already ascertainable and 

 will presumably be indicated in the report to be issued on the 

 trials, farmers in general have no idea of what it means in 

 actual practice or its relation to their problems. 



Caterpillar-track Machines. — Another problem is that of the 

 relative efficiency of wheels and caterpillar track. Eeference 

 was made to this subject in the comments on last year's 

 trials in the issue of this Journal for October, 1919. No 

 definite opinion can be stated until a very protracted test is 

 made under more varying conditions than those which pre- 

 vailed this year. The caterpillar type is intended to avoid 

 undue weight on the land. The general features of the 



