404 REPORT — 1901. 



Mr. Aitken : — 



APPENDIX. 



Abstract of Suggestions. 



(a) The dynamometrical apparatus for recording the different con- 

 ditions in the resistance of road vehicles to traction would require to be 

 self-contained ; that is, a separate machine on wheels or an apparatus 

 attached to the loaded vehicle. For slow-travelling traffic all the diffei'ent 

 items which go to make the net result might, with the exception of 

 vibration, be accommodated on an apparatus with wheels, placed between 

 the prime mover and the vehicle hauled. For fast-travelling traffic such 

 an apparatus could not, he imagines, be used with safety, so that the 

 appliance would require to be fixed to the motor or loaded vehicle. At a 

 high velocity the viagraph would not be available, but records could be 

 made previous to carrying out the experiments with the road vehicles. 

 The connecting appliance would require to be short-coupled in order to 

 reduce oscillation. 



(b) The scheme of experiments would cover all descriptions of pavements 

 and macadamised roads. In the experiments the viagraph must play a 

 conspicuous ■ part ; and if the speed, pull, and vibration could be auto- 

 graphically recorded to correspond with the ' viagram ' the different 

 conditions could be seen at a glance, while a scale of measurements would 

 give definite results. 



For experiments at high speeds a viagraph section would require to 

 be made first, a record taken one way corresponding with the exact 

 position which would be occupied by the vehicle, and another back and 

 corresponding with the width between the wheels of the vehicle, so as to 

 arrive at a mean value of the irregularities of the road surface. A 

 distinctive mark made by the viagraph in previously passing along the 

 road would guide the driver of the experimental vehicle in following the 

 proper course. 



The pull, ikc, on the best laid asphalte pavement might be taken as 

 the standard to work from, and which in all probability would give about 

 5 feet per mile of unevennoss. 



Each road surface from that point and for each succeeding 5 or 10 feet 

 per mile up to 100 feet of irregularity could be tested on level stretches 

 and on gradients at different speeds to ascertain the pull required and the 

 amount of vibration. 



The extent of the unevenness recorded by the small wheel of the 

 viagraph, and that of wheels of varying diameter, could be ascertained 

 experimentally, from which, no doubt, some kind of formula could be 

 deduced. 



Mr. Aveling :- — 



The Sub- Committee might be divided for the purpose of making trials 

 into — 



(a) In heavy or road locomotive class ; 



(b) In medium or steam lorry class ; 

 (r) In automobile or light class ; 



so that the experiences of each of the sub- Committees in their own par- 

 ticular line should be more directly available. 



