The Vaporizing Of Paraffin for High-Speed Motors
(Electric Ignition Type)

2 VAPOBIZING OF PARAFFIN. considerable extent to produce the different commercial grades in varying proportions to suit the demand, and, as the more volatile constituents are now required in ever increasing quantity for motor spirit or petrol, the paraffin or lamp-oil grades are now of a more regular composition than used to be the case. However, the effect of processes having the object of extracting a higher per cent age of motor spirit at the expense of the paraffin series, on an oil engine of the vaporizer class, is more beneficial than otherwise, especially in those of the larger series; but conversely, all paraffin grades are, as a consequence of this, more difficult to use satisfactorily in high-speed engines depending 011 an exhaust-heated vaporizer, and this is more pronounced in engines required to run, as in automobiles, under varying load conditions. This also explains in some measure the reason wliy so few tractors, motor lorries, and of course ordinary touring cars have hitherto been run on paraffin, despite its much lower cost and freedom from taxation. But with the enormous demand for motor spirit in- creasing in a greater ratio than the production, coupled with present curtailments in supply due to shipping restrictions, its price has now advanced to such a point as to practically prohibit its use for stationary and tractor motors, and indeed for all classes of road-car motors used for commercial purposes. In this connection we find that on the Continent, for some two or three years past, benzole has been more extensively used for these purposes than motor spirit; the 1200 motor omnibuses in service before the war in Paris, for instance, were all driven by benzole, and as the difference then