TRACTION ENGINES 



439 



upon it. It is obvious that this puts undue strain upon 

 the boiler shell at a point where it is the weakest. The 

 weight of the boiler and the engine is thrown upon these 

 brackets and in such a manner that it has a tendency 

 to throw the inside of the axle down and the outside up. 

 This will tend to throw the tops of the drive wheels to- 

 gether and the bottoms apart. The weight is also thrown 

 upon these axles so that that part of the hub of the fly- 

 wheel next to the engine will wear faster than the middle, 

 and as a result the wheels will tend to become wobbly 

 in action and wear the teeth of the transmission gearing 

 unevenly. A truss bar similar to that of Fig. 318 re- 

 moves a great deal of the strain from the water leg, and 



FIG. 319 



also tends to hold the axles in line with each other, and 

 thus keep the drive wheels more nearly vertical. An- 

 other method of side mounting an engine is shown in 



