93 



Fig. 4. 



Fig. i. Tests of a Wrought Iron Car Axle. 



Fig. 5. Car Axle. 



Subdivision of Power. By J. J. i^LAXHER. 



While economy in the use of power should be secondary to increased output, 

 yet careful attention to details will often greatly reduce the useless waste of power. 



It is well known among engineers that there is a very great percentage of loss 

 due to shaft friction, which, in shops where the buildings are more or less scat- 

 tered, is probably not far from 75 per cent, of the total power used. In two cases 

 known to the writer these losses are 80 and 9.S per cent, respectively. 



No matter how well a long line of shafting may have been erected, it soon 

 loses its alignment, and the power necessary to rotate it is increased. 



In machine shops with a line of main shafting running down the center of a 

 room, connected by short belts with innumerable countershafts on either side, 

 often by more than one belt, and, as frequently happens, also connected to one 

 or more auxiliary shafts which drive other countershafts, we can see why the 

 power required to drive this shafting should lie so large. 



