CATALOG OF THE MECHANICAL COLLECTIONS 171 



throttle valve. A conical piece of wire gauze directly above the jet 

 acted to assist the "atomization" and subsequent vaporization of the 

 mixture which impinged upon the gauze. 



CARBURETOR OF THE MANLY ENGINE, 1901 



Plate 34, Figube 3 



U.S.N.M. no. 310194 ; original ; deposited by the Smithsonian Institution ; photo- 

 graph no. 18081. 



This is an elementary type of surface carburetor. It consists of a 

 large copper tank (approximately 10 by 18 by 24 inches) filled with 

 small pieces of a porous, cellular wood (tupelo wood) and fitted with 

 a gasoline inlet valve, two gasoline drains, a great many small air- 

 inlet tubes, and a large outlet from which the mixture was drawn by 

 the suction of the engine. 



This carburetor was adopted by Charles Manly in 1901 for the 

 engine of the Langley Aerodrome after testing the various mixing 

 valves and float-feed carburetors then available. It performed satis- 

 factorily in the attempted flight and kept the engine running after 

 the aerodrome turned over on its back. 



ZENITH CARBURETOR, MODEL U5, 1921 



U.S.N.M. no. 308362; original; gift of the Zenith-Detroit Corporation; not 

 illustrated. 



In this carburetor two fuel nozzles are employed in combination to 

 obtain automatic regulation of the strength of the mixture regardless 

 of the changes in suction, due to variations of the speed and load of 

 the engine. One nozzle flows a constant amount of fuel regardless of 

 suction and alone would produce a mixture growing leaner and leaner 

 as the suction increased. The other nozzle flows more fuel as the 

 suction increases and alone would produce a richer mixture as the 

 suction increased. The two in combination give an average mixture 

 of correct proportions. This principle was developed by M. Baverey, 

 of France, 1906-1908. 



The carburetor consists of three compartments : The float chamber, 

 the mixing chamber, and a small gravity chamber. Gasoline feeds to 

 the bottom of the float chamber through a needle valve controlled by a 

 float to maintain a constant level of fuel within the carburetor. 

 Within the mixing chamber are a main gasoline nozzle surrounded 

 by a second annular nozzle and a small orifice just opposite the 

 edge of the disk throttle valve. The small orifice and the annular 

 nozzle are in permanent comnmnication with the small gravity 

 chamber, which is open to the air and which is supplied with gaso- 

 line at a slow but constant rate from the float chamber. At starting, 

 the gravity chamber is full of gasoline, and a rich mixture is ob- 



