2 Reynolds, On the SUpperiness of Ice. 



That surfaces of machines would not slip over each 

 other without grease was well known and followed out, 

 but the physical significance of the action was apparently 

 not questioned until, in 1884, Mr. Beauchamp Tower,* while 

 making experiments as to the resistance of a railway 

 journal, accidentally came across a fact of very striking 

 significance. 



In this experiment, instead of using an axle, Mr. 

 Tower used an overhanging shaft driven by a steam 

 engine, the shaft being supported on bearings in the 

 usual manner. The overhanging portion of the shaft was 

 turned to the same shape as one of the journals of a 

 railway wheel, four inches in diameter and six inches long. 

 On this journal the ordinary axle-box was suspended, the 

 load to correspond with the proportion of the weight of 

 a loaded truck being suspended from the axle-box under- 

 neath the shaft. The axle-box had the usual brass 

 wearing-piece, and the provision for lubrication was, as 

 usual, an oil or grease cup communicating through a 

 vertical oil-hole, so that the oil might descend by gravi- 

 tation through the brass on to the surface of the journal, 

 and thence escape, after being used, to the ground. This 

 was in the first instance, but, after experimenting in this 

 way, Mr. Tower proceeded to find what would be the 

 effect on the resistance if, instead of allowing the oil or 

 grease to escape freely from underneath the journal, the 

 whole under side of the journal was encased in a vessel, 

 so as to form a bath of oil in which the journal would be 

 completely covered. 



In commencing these experiments with the bath, Mr. 

 Tower noticed with surprise that, although the oil in the 

 bath did not cover the top of the brass when the journal 

 was at rest, when in motion the oil escaped upward against 



'' Proc. Inst. M. E., Nov. 1883 and Jan., 1884. 



