is called the nozzle or nipple. The burners of the Weston, Milwaukee, and many other American cars are practically similar to the Locomobile, and so is that of the Reading, but in this latter burner the vapour is injected from the centre of the bottom plate, so that the half-inch air-tubes have no break in their disposition, and if the petrol be inadvertently left turned on, there is no chance of it flooding the burner and being ignited when the burner is lighted, as it runs out on to the ground.
Vaporising the Fuel.—The petrol is forced from the petrol tank to the burner by air pressure, a cylindrical vessel is connected with the petrol tank, and it is pumped to about 45 lbs. pressure in the Locomobile and most cars of similar type. The pressure is obtained by means of an ordinary bicycle pump, and it occasionally requires a few strokes of the pump to maintain it as the petrol is used up. An air-pump driven by steam can be fitted to the Locomobile, so that the hand-pump need not be used. To vaporise the liquid, it is passed by means of a tube up through the boiler across the top of it, and down again through another tube, the heat of the boiler being found sufficient to transform the liquid into gas. Thence it passes into the burner. This is the Locomobile arrangement. In the Weston the petrol is pumped through a tube which runs straight across the fire-box, or circular case containing the burner, the heat of the fire vaporising it. In the Reading it is passed in tubes through the boiler once, and also over the fire. It will be seen that these methods, which are mentioned as examples, all require that the burner shall be in operation before the process of vaporising can be commenced, and as the burner can only consume vapour, some additional method is necessary to obtain the initial heat.
Starting the Burner.—The Weston starting apparatus is fed by a separate tube from that which supplies the main burner. Its working is as follows:—The tap a (fig. 3) is opened so that the petrol flows through the tube f, and by opening a small tap b the spirit runs into a little square box, outside the fire-box by the pipe f1. In this box, g, is a small cup,
