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

98 VAPORIZING OF PARAFFIN. car motor, the essential factors for a quick start, reliable and steady running under all ordinary conditions are of greater importance than fuel économy, especially in the case of cars required for town work ; but for long distance touring with petrol costing from three to four times as much as paraffin, it is worth while to put up with certain inconveniences inseparable even with the most perfect of the known methods of using a fuel that must be vaporized as well as carburetted, and for the heavier commercial cars, it is obviously of still greater importance that the idiosyncrasies of the paraffin motor should be studied, so that its advantage may be fully realised. As paraffin can be used in any ordinary petrol motor— excepting those of the smaller sizes, for which there would be comparatively little advantage—when fitted with a carburettor vaporizer, i.e., a carburettor combined with a separate vaporizing attachment, and arranged to be heated up by a preliminary run on petrol, a motor so fitted has the advantage that it can be run on either fuel; but in order to obtain the best results, it is obviously necessary to be able to cut out the vaporizer in starting, as by this means not only can the motor be started with a single pull-over, as with an ordinary petrol car- burettor—the mixture then not having to traverse the vaporizing space, but oan be changed-over to the paraffin feed in less time than when the mixture is drawn through the vaporizer, owing to the cooling effect of the volatilized petrol on the heating surface. Moreover, the motor can, if desired, be run on petrol, and with practically the same efficiency as with an ordinary carburettor of good make. Several forms of carburettor vaporizers have already