CATALOG OF THE MECHANICAL COLLECTIONS 129 



the direction of the axis of the tube and is adjusted by a hand wheel 

 at the side of the injector, the shaft of which projects into the 

 injector and carries a small pinion that meshes with a short rack 

 formed on the tube. Packing around the sliding tube is dispensed 

 with by forming the tube in two parts, a fixed part and a sliding 

 part, and proportioning the two parts so that the ends of the sliding 

 part will be "opposite that part of the passing current where it has 

 attained its highest velocity; and by this arrangement the passing 

 liquid has no tendency to escape but rather to draw in air or fluid." 



GIFFARD-SELLERS INJECTOR, 1868 



TJ.S.N.M. no. 309372 ; original patent model ; transferred from the United States 

 Patent OflBce ; not illustrated. 



This model was submitted with the application for the patent? 

 issued to William Sellers, of Philadelphia, Pa., March 3, 1868, no. 

 75059. 



The objects of the improvements incorporated in this design of 

 injector were to enable injectors to throw a smaller quantity of water 

 without affecting their maximum capacity, to permit them to draw 

 water from a lower level, and to make the waste orifice self-closing. 



FRIEDMAN INJECTOR, 1869 



U.S.N.M. no. 308G79 ; original patent model ; transferred from the United States 

 Patent OflBce; not illustrated. 



This model was submitted with the application for the patent 

 issued to Alexander Friedman, of Vienna, Austria, April 6, 1869, 

 no. 88620. 



The model represents a steam injector designed for elevating or 

 forcing water and reducing the shock produced by the sudden con- 

 densation of steam when brought into contact with the water. 



The injector is of the usual form with the addition of a small 

 auxiliary steam jet, or ejector, which serves to draw water into the 

 mixing chamber before the main steam valve is opened. A safety 

 cock is also provided, which permits a part of the water to escape as 

 the pressure is being raised to the degree sufficient to overcome the 

 resistance against which the injector is working. 



SELLERS SELF-ADJUSTING INJECTOR, 1876 



U.S.N.M. no. 309558; original; gift of William Sellers & Co., Inc.; not illus- 

 trated. 

 This is the 1876 commercial form of the floating combining tube, 

 self-adjusting injector first patented in 1865 (see above). It is 

 constructed for convenient operating and repairing and is started, 



