CATALOGUE OF THE MECHANICAL ENGINEERING COLLECTION, 



27 



and exhaust pipes, which branch off from trunk lines so as to ex- 

 tend to each side of the cylinder, terminate in a steel-lined head or 

 block which fits closely to the steel surfaces mentioned above. The 

 openings in these blocks are of the proper diameter and distance 

 from each other, so that all steam connections are shut off when the 

 piston is at the end of its stroke and open when it is in the middle of 

 its stroke. The changes of steam are made without any movement 

 of the steam-conducting headpieces, but by the movement of the 

 cylinder alone. Cat. No. 251,293 U.S.N.M. 



Model of W. Sellers Oscillating Steam Engine. TJ. S. Patent, No. 127928, 

 June 11, 1872. Transferred from United States Patent Office. 



The engine is equipped with a curved link or arc, concave toward 

 the axis of oscillation of the cylinder, which is provided with a 



FIG. 7.— WORTHINGTON STEAM PUMP, 18.59. 



means of varying and adjusting the degree of its obliquity; an ec- 

 centric which operates this link; and a sliding block or die which 

 transmits motion to the valve of the engine. The objects attained 

 are, first, providing an improved means of operating the valve of 

 the engine; and, second, providing an improved means of guiding 

 the piston rod and diminishing the wear upon the stuffing box. 



Cat. No. 251,296 U.S.N.M. 



Model of H. E. Worthington Steam Pumping Engine, TJ. S. Patent, No. 

 24838, July 18, 1859. Transferred from United States Patent Office, 



The engine consists of two direct-acting pumping engines so com- 

 bined that the steam and exhaust valves of each engine govern the 



