ON THE RESISTANCE OP ROAD VEHICLES TO TRACTION. 405 



Mr. W. Worby Beaumont : — 



A. Resistance to be obtained by a, say, 8-horse power Daimler car 

 hauling : 



(a) A light two-wheeled vehicle with iron tyres and 



1. Running light. 



2. With 3 cwt. load. 



3. With 6 cwt. load. 



(b) A light four-wheeled vehicle with iron tyres. Tests same as above 

 for two- wheeled trap. 



(c) A heavier type of two- wheeled vehicle with iron tyres and 10 cwt. 

 and 1 ton loads. 



(d) A heavier four-wheeled vehicle, same load. 



B. Hauling vehicles same or similar to («), (6), (c), (d), but with 



(a) Solid rubber tyres. 

 (6) Pneumatic tyres. 



C. Iron- hoop tyres to be shrunk on vehicles in (a), (b), (c), (d), of double 

 width makers ordinarily put on same, and same tests again made. 



D. Trials of two-wheeled vehicles to be made with two different sizes 

 of wheels, say 33 inches and 48 inches. 



E. Angle of draught to be at least two, say (1) horizontal, i.e., level 

 with axle ; (2) upward inclination of, say, 20 degrees. Trials made with 

 skeleton vehicles, all tests to be made (1) on level, smooth asphalte ; 

 (2) on all sorts and conditions of other level roads ; (3) on all sorts of 

 roads of different grades. 



Speeds to be the four speeds of the hauling car. 



Mr. J. Brown : — 



The surface of the roads upon which the experiments are to be made 

 should be tested in two particulars : — 



(a) The smoothness. 

 (6) The hardness. 



The smoothness of the roads should be tested by means of his viagraph, 

 to which he suggests the addition of a skate with the curved outline 

 corresponding to a wheel. 



For the hardness an apparatus in which the weighted stamper is raised 

 and lowered at intervals might be used, the amount of yield in the road 

 being autographically recorded. 



Mr. A. Mallock presented a design for a dynamometer using a single 

 wheel. The arguments for such were as follows : — 



(a) This requires at most only half the number of experimental 

 wheels. 



{b) Changes from one form of wheel to another can be made more 

 rapidly. 



(c) The tractive force can be more regularly measured. 



(d) The effective load carried by the wheel can be known with 

 certainty. 



Mr. Mallock's designs for the single-wheel dynamometer may be 



