Motor Road Transport For Commercial Purposes
(Liquid Fuel, Steam, Electricity)

STEAM WAGONS AND TRACTORS 97 by law, but in such a case as that given above this drawback is hardly calculable. In addition to this kind of delivery the steamer is eminently suitable for transporting heavy loads at low speed on long- distance runs. There is little doubt that the petrol chassis is not really adapted for use with iron tyres, although the writer has seen good work done by such machines abroad; this is, however, the exception, and the trader who wishes to employ a hard-tyred vehicle will be wise to use one driven by steam. In making a choice of power between steam and oil, the real determining factor is annual mileage. If the required figure is high, the slower type of vehicle will not be able to undertake the work, because, although it can run long-distance journeys and economically, the limiting rate of speed will prevent it from doing a big yearly mileage. In any district where coal or coke is comparatively cheap it will probably pay the trader to run steam wagons in preference to petrol lorries ; moreover, the former can be so designed that they can be fired on wood if necessary, and for colonial use this may be a decided asset. Steam Tractors. Concerning the steam tractor as distinet from the steam wagon, the chief point to bear in mind in making a choice between the two is that, as a rule, where the load to be transported is of a weight which cannot be carried on a single trailer the tractor—which bears no useful load itself—will not prove the best invest- ment. To conform with the Heavy Motor Car Act, it must weigh. not more than 5 tons unloaded, and unless it is brought under the traction engine regulations it cannot draw more than one trailer—with a load of about 5 tons—at a time, and this at the rate of 5 miles 7—(1889)