Page:Motors and motor-driving (1902).djvu/147

Rh versa, c is the gauze through which the crude gas and air pass.

(2) The Benz Carburetter.—The second type combines features of the first and third, inasmuch as the principle of carburation is the same as the first, i.e. surface type, and the method of supplying petrol to the carburetter is on the same principle as the third, float feed. The chief examples of this type are to be found in the 'Benz' cars. The apparatus consists of a cylindrical vessel having a small compartment in the bottom through which a portion of the exhaust gases passes. The heat so derived assists in vaporising the petrol. A tube reaching to a point just above the level of the spirit admits the

necessary air, which may be regulated by a cap covering the holes through which the air is drawn. Another pipe projecting into the vessel conveys the carburetted air to the combustion chamber of the cylinder, into which it is drawn by the suction of the piston. The petrol supply pipe enters the side of the carburetter, and is bent downwards. On to the inside of the carburetter a lever is hinged, carrying a cap which closes the inlet pipe, when the opposite end of the lever is raised by a float contained within the carburetter. When the level of the petrol sinks, the float sinks with it, releasing the pressure from the end of the lever, and so admitting a fresh supply of petrol.