84 



BULLETIN 119, U. S, NATIONAL MUSEUM. 



is a large spur wheel. This cog engages two cogs on either side of it 

 secured to the axles of the middle wheels of the trucks, and through 

 cranks on the extremities of these axles and connecting rods the 

 power is communicated to the outside wheel axles. Thus all eight 

 wheels are driving wheels. Cat. No. 251,271 U.S.N.M. 



Model of Locomotive Invented by M. W. Baldwin. U. S. Patent No. 2759, 

 August 25, 1842. Transferred from the United States Patent OfSce. 



This locomotive contains features which will permit the wheels 

 and axles to adapt themselves to the curves and undulations of the 



FIG. 39. ASA WHITNEY LOCOMOTIVE, 1840. 



railway bed. An adjustable pin is fixed vertically above the axles 

 and to the frame on each side of the boiler, and extends downward and 

 through a vibrating bar, terminating on the upper surface of the 

 multileaf spring. The fore and aft ends of the spring are connected 

 to the boxes in which the wheel axles revolve. The boxes are made 

 so that they swivel in the plumber blocks which receive them, by 

 boring cylindrical recesses in the blocks. These blocks are secured 

 to the vibrating bar so that the parallelism of the axles is undis- 

 turbed. Cat. No. 251,274 U.S.N.M. 



Model of Locomotive Invented by G. H. NicoUs, 1848. TJ. S. Patent No. 

 5532. Transferred from the United States Patent Office. 



The object of this invention was to maintain the tractive power of 

 a locomotive on ascending grades. The nature of the invention con- 



