CATALOGUE OF THE MECHANICAL ENGINEERING COLLECTION. 79 



hibited at the Centennial Exhibition, 1876, and at the Exposition of 

 Railroad Appliances, Chica<^o, 1883, It was placed in the United 

 States National Museum in 1885, where it remained until 1893, when 

 (April 17-22) it was run under steam from New York to the AVorld's 

 Columbian Exposition, where for a time it made daily trips upon the 

 exposition tracks. On December 13, 1893, it was returned to Wash- 

 ington, D. C, having made the last trip under steam on that datfe. 



The original dimensions were us follows: Weight, 10 tons (22.425 

 pounds). Boiler, 13 feet long, 3 feet G inches in diameter. Cylinders, 

 9 by 20 inches. Driving wheels, 4 feet 6 inches in diameter ; cast-iron 

 hubs ; locust spokes ; tire of wrought iron, shrunk on ; flange, 1^ inches 

 deep. Sixty-two flues, 7 feet 6 inches long, 2 inches in diaineter. 

 Furnace, 3 feet 7 inches by 3 feet 2 inches high. Steam ports, 1^ by 

 6^ inches; exhaust ports, 1^ by 6^ inches. Throw of eccentric, 3^ 

 inches. Grate surface, 10.08 square feet. Fire-box surface, 36 square 

 feet. Flue surface, 213 square feet. Cat. No. 180, 001 U.S.N.M. 



Fir.. 35. '• JOHN BILL." AND TRAIN, 1831. 



Model of Locomotive " John Bull " and Train. Made in the Museum. 



This model represents the locomotive and train as it originally 

 appearecl on the date of the initial trip, November 12, 1831. By 

 comparing the locomotive model with the actual engine as it now 

 stands, the outstanding feature to be observed is the absence in the 

 former of the pilot or " cowcatcher." The necessity for a pilot to 

 remove obstructions off the track caused Isaac Dripps, master 

 mechanic of the railroad, to design and add this forecarriage, which 

 not only performed its specified duty but also carried some weight 

 off the front driving wheels and performed, in a way, the functions 

 of the swiveling truck. 



Again, it will be observed that in the model the driving wheels 

 are connected by rods (one on each side), while these are absent 

 in the full-size machine. These rods were never used, owing to the 

 sharp curves on the road. 



The passenger coaches used were simply stage coaches, common at 

 that time, equipped with flanged wheels. Cat. No. 233,510 U.S.N.M. 



