Plate 18. 



Bottom of rearing car, showing detail of lower portion of the propeller shaft and 

 its socket in the floor of the car. Propeller shaft, long ascending portion made 

 of gaspipe 1 ; short descending portion of shaft made of steel to fit into the socket 

 2 ; four way pipe coupling 3 ; gaspipe to which the blades are strapped 4 ; strap 

 holding propeller blades tight 5 ; socket which receives lower end of the shaft 

 6 ; flange screwed to the floor 7 ; upper steel portion of the propeller shaft discon- 

 nected from the lower one and hanging down from the shaft-beam 8 ; view of 

 shaft-beam from under side 9 ; window in bottom of car 10 ; base of propeller 

 blade showing in section the shape of the long bevel 11. 



Plate 19. 



Detail of a coupling connecting the two parts of the propeller shaft, 1 and 2, 

 long shaft beam; 3, 4, upper portion of shaft connected with gears; 5, set screws; 

 6, 7, 8, solid steel shafting, coupling, and gas pipe shafting, respectively; 9, meas- 

 uring stick, with joints six inches long. 



Plate 20. 



Detail of gears at junction of transverse, 1 and 3 and 4, and longitudinal shafts. 

 2, 5, gear on longitudinal shaft 2, reduces speed one half, sludge pan, 6. 



Plate 21, 22. 



Detail of device for throwing propeller in and out of gear. By pulling the lever 

 the propeller shaft and its gear drop. 



