Fig. 195 illustrates a portable gasoline lamp in which a convenient and efficient form of generating mechanism is combined with an attractively proportioned exterior. The lamp works on the principle of the hollow-wire system, the base serving as a storage and pressure tank, the frame of the lamp acting as the tube for supplying the lamp with gasoline, and the canopy containing the generating mechanism. [Illustration: FIG. 195.--Portable gasoline mantle lamp.] The tank in the base is filled with gasoline at the opening _E_, which is made air-tight by a screw-plug. The plug also contains an attachment piece for the air pump, which furnishes the pressure to the gasoline. The hollow standard reaches to the bottom of the tank and through it the gasoline is forced to the point marked _A_, where the gasoline enters the generating mechanism. This part of the lamp, which is entirely concealed by the lamp canopy, is shown in detail in Fig. 196. The reference letters in Fig. 195 apply to the same parts in the detail drawing. The gasoline enters an asbestos-packed tube _F_ at the point _A_, and after percolating through the tube, reaches the regulating valve at the point _G_. The hand-wheel _B_ opens and closes the valve, and thus controls the entrance of the gasoline to the generating tube _H_, where it is converted into the vapor. The vapor now needs only the addition of air to make it the desired gas for illuminating the mantle. The vapor from the generating tube escapes at the small hole _K_, located directly under the mixing chamber _M_. The supply of air is received through the tube _C_, provided with a regulator, which is readily accessible from the outside of the lamp. The mixture of gasoline vapor and air is accomplished as in the other lamps described, through the Bunsen tube _N_. In this case, the Bunsen tube is extended and increased in size to produce a mixing chamber of considerable volume. The mantle is attached to the tip _O_. The tip, like the one already described, is made of German silver and constructed to produce a flame that will entirely fill the mantle. This lamp is provided with a special means of keeping the opening _K_ free from accumulations. The opening _K_, through which the gasoline vapor escapes from the generator, is very small and a slight stoppage will materially interfere with the flow of the vapor and thus impair the illuminating effect of the light. A lever _D_ operates an eccentric which engages the piece _P_, to which is attached a pin that readily enters an opening _K_, when the lever is turned. Any accumulation which may lodge in the opening is instantly removed and the needle returned to its place by a turn of the lever _D_. [Illustration: FIG. 196.--Sectional view of the generator for the American hollow-wire gasoline lamp.]