ON THE RESISTANCE OF ROAD VEHICLES TO TRACTION. 403 



and Local Boards. A circular was drawn up with this end in view ; but 

 pending the consent of the General Committee an application for funds in 

 the above directions has not been pressed. 



The step has been taken, however, of appointing Mr. T. C. Aveling, 

 a member of the Committee, who is conversant with the traction-engine 

 world, as Hon. Treasurer. 



Meanwhile, an offer having been received from Sir David Salomons to 

 lend to the Committee for an indefinite period, to alter as they pleased, a 

 motor-car, it was determined in accepting this kind offer to proceed at once 

 with a series of preliminary experiments, which would pave the way for 

 futui'e and more complete investigations. During the past few months 

 work has been steadily proceeding upon the motor-car, the cost of new 

 engines for which is being defrayed by Sir D. Salomons. Although great 

 delays have been experieiiced with the engines, it is hoped that very 

 shortly a preliminaiy series of the experiments may be commenced. 

 These it is proposed to make in the first place with single wheels, with 

 different kinds of tyres. The track for this purpose in the first place 

 would be artificial, consisting of different kinds of materials laid in a 

 trough or trench, about eighteen inches or two feet in width, so that the 

 dynamometer itself can be thoroughly tested when the car is running 

 upon a road of level surface. 



In this way the autographic records obtained for materials, such as 

 sand wet and dry, loose stones, artificial projections of cross pieces of 

 wood of different sizes and differently pitched, can be thoroughly under- 

 stood and constants of the dynamometer obtained, so as to enable the 

 actual road trials to be made without unnecessary delays. 



This the Committee consider to be very important matter, since the 

 difficulties involved in securing permission to make, and in actually making, 

 trials upon the roads themselves should be reduced to a minimum. The 

 new viagraph of Mr. Brown has been received and is awaiting these trials. 

 It has been altered by the important addition of a device for attaching 

 different curved surfaces, representing segments of wheels of different 

 diameters. The rise and fall of this curved piece is autographically 

 recorded, and from experiments which have already been made by Mr. 

 Aitken it is clear that the actual contour of the road or surface being 

 experimented upon can be clearly indicated at the same time that the 

 actual resistance is being recorded by the dynamometer. The Committee 

 have not thought it advisable in the present report to publish a detailed 

 description of the dynamometer, since the instrument may possibly 

 undergo considerable modification in the course of the experiments. 

 Further, they consider that in view of the fact that the work of different 

 experimenters on road resistance (an abstract of which has, in accord- 

 ance with their instructions, been prepared) consists in many cases 

 in the enunciation of laws and formulae, it will be better, instead of 

 publishing at the present juncture this abstract, to wait until their own 

 experiments can be compared with those of previous workers, particularly 

 as, for the first time, it will be possible to make observations at any 

 required speed from the highest to the lowest velocities of practical 

 interest. 



The grant of money already given will not be sufiicient to cover expendi- 

 ture already incurred ; therefore they make application for a further sum 

 of equal amount (viz., 161.), with permission to I'aise the additional sum 

 they require, and for the reappointment of the Committee. 



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