348 REPORT— 1902. 



some definite point over a given piece of road whose surface is of the 

 desired type, a return run being made over the same road back to the 

 starting-point. By taking the mean values for the double journey, 

 out and return, the effect of inclines is eliminated. The load is then 

 increased and the route traversed again, and so on. For the first few 

 experiments for a given load the speed was given a succession of values 

 ranging from 6 to 14 miles an hour, all in the outward run, just 

 remaining constant at each speed for a sufficient distance to give a 

 definite reading on the paper, and during the return journey the speeds 

 were gone through in the reverse order, so that as near as possible the 

 same piece of road was traversed at the same pace in each direction, 

 this procedure being repeated for each load. This was not found very 

 satisfactory on the whole, so that for the succeeding experiments a given 

 space was covered both on the outward and return journeys at a definite 

 speed. The same journey was then traversed under a higher constant 

 speed, and so on, until sufficient readings had been obtained to give a 

 curve. This process was gone through for each load. This method, 

 although slower than that tried at first, was found to give much more 

 satisfactory results. As the dynamometer has only been completed 

 such a short time, the trials are as yet only preliminary ; the general 

 results, however, tend to confirm those of previous investigators. The 

 diagrams to be shown at the meeting have not been reproduced here, it being 

 thought unnecessary, as they will have to be all reproduced in the next 

 report, by which time the striking results brought out by them, if duly 

 confirmed, will by repeated experiment have been placed beyond question. 



The first experiment was conducted near Sefton with an ordinary 

 light lurry wheel, 40 inches diameter, having a .3-inch iron tyre, slightly 

 rounded in section. This wheel was kindly lent by Messrs. T. Coleburn 

 & Son, Cherry Lane, AValton, who have also promised to lend different 

 sizes of wheels of a similar type for the experiments. 



The wheel was mounted on a pair of springs, 3 feet 2 inches centres, 

 each having six plates 2^ inches by ^'^ inch. Three different runs were 

 made with loads of 3^, 5h, and 8^ cwt. respectively, with velocities 

 ranging from 6 to 14 miles per hour. The results obtained, however, 

 were not very satisfactory. 



The second series of experiments were made with the same wheel 

 and springs as were used in the fii'st series, viz., light lurry wheel, 

 40 inches diameter, having 3-inch tyre slightly rounded in section, the 

 springs each consisting of six plates 2^ inches by i',; inch. The route was a 

 portion of Regent Eoad, Bootle, which runs parallel to the line of docks, 

 and is quite level. It is paved with setts, 6 inches by 3 inclies, with a 

 1-inch gap, and has a regular but fairly rough surface. Two runs were 

 made with loads of 6 and 8^ cwt. respectively, at speeds of from 5 to 14 

 miles per hour. 



A wall-diagram will be exhibited showing the results of the series of 

 experiments. For both loads the tractive effort increased rapidly with 

 the velocity, and at the same time was fairly proportional to the load. 

 A diagram showed the results plotted as tractive effort per ton. 



The third series of experiments were made with a pneumatic-tyred 

 wheel 24 inches diameter, 2| inches tyre. The springs, 3 feet 2 inches 

 centres, each consisted of two plates 2} inches by {^^ inch, This trial 



