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

PETRÖL C ARBURETTORS. 21 or when a car is running along the side of a cambered road; the effect of this can be seen in the two illustra- tions, Figs. 17 and 18, the latter showing the drop of level in the spray nozzle with a 10 per cent. tilt. For this reason, it is obviously better to fix the float cistern at the side of the carburettor than either in front or rear, although there is a little advantage to be gained by placing it a few inches forward of the spray-nozzle, for the reason that by this means the feed is auto- matically slightly increased on an upgrade. The effect of difference of level in the nozzle due to camber or gradient was first recognised by the firm of De Dion, who introduced in 1900 a form of central-feed float cistern, shown in Fig. 19, in whicli the float t is made in the form of a ring and arranged to surround the choke-tube, consequently the level of the liquid supplied to the spray nozzle is unaffected by tilting of the cistern in either direction by the causes named; in modern practice, it is noteworthy to add, it has become more and more customary to ftt the carburettor with a central feed, or as near to it as possible, notwith- standing the comparative inaccessibility of the float val ve. The simplest adaptation of the central-feed principle is shown in Fig. 20 ; the float in this carburettor, known as the Ware and referred to again, is arranged directly over a weighted feecl valve, and is balanced, inasmuch as the float rests on a pair of spring hinges. In another form (Fig- 21), the Shebler, and in extensive used in America, the float is fork shaped and made from a solid slab of compressed cork with a hinged suspension; in this, the cork is made impervious to petrol by a coating