CATALOG OF THE MECHANICAL COLLECTIONS 51 



HIGGINSON STEAM ENGINE, 1877 



U.S.N.M. no. 309194; original patent model; transferred from the United States 

 Patent Office ; not illustrated. 



This model was part of the application for the patent issued to 

 Andrew Higginson, of Liverpool, England, October 23, 1877, no. 

 196451. 



The engine represented in the model is a radial reciprocating engine 

 with three single-acting cylinders. The admission of steam and the 

 exhaust are controlled by ports in the cylinder walls and in the piston. 



A steam and an exhaust port in each cylinder wall are alternately 

 connected to the space above the piston by being uncovered by a single 

 port in the skirt of the piston. The piston oscillates in the cylinder to 

 uncover either port, the direction of rotation of the crank determining 

 which port is opened first. The engine, therefore, will run in either 

 direction in which it is started. The "cylinders" and pistons are 

 rectangular in section. 



VERTICAL STEAM ENGINE 



U.S.N.M. no. 309685; model; gift of Robert E. M. Bain; not iUustrated. 



This is an operating model of a small, high-speed, vertical steam 

 engine, of a type that has been widely used since about 1880 to furnish 

 small powers for general use. They have had a wide application in 

 driving small shops, electric generators, small mine hoists, and flour 

 mills and in larger sizes for rolling mills. They have now been gen- 

 erally replaced by more modern engines and electric drives. 



The model has a double-acting vertical cylinder supported on a 

 tapering columnar frame with openings in the side to allow free ac- 

 cess to all working parts within. The cross-head slide and bearings 

 are cast with the column. A slide valve operates in a steam chest on 

 the side of the cylinder and is driven by an eccentric on the shaft. 

 The crankpin is carried in a counterbalanced crank disk. The engine 

 in the model is direct-connected to a hoisting drum. 



BAKER STEAM ENGINE, 1878 



U.S.N.M. no. 309246; original patent model; transfex-red from the United States 

 Patent Office ; not illustrated. 



This model was submitted with the application for the patent issued 

 to John G. Baker, of Philadelphia, Pa., September 10, 1878, no. 207936. 



The model represents a small vertical single-acting engine in which 

 the connecting rod is attached to the piston by a ball-and-socket joint, 

 and the space enclosed within the cylinder and the face of the piston 

 is alternately opened to the exhaust and to the steam pipes by rotating 

 the piston laterally in the cylinder. The piston is rotated by a simple 

 bent rod, one end of which turns and slides in an opening in the con- 



