340 



Scientific Proceedings, Ro!/(tl Dublin Society. 



From the results in these three tables we see that the harder the wire or 

 the greater the rigidity the greater is the fatigue, and, also, that as the 

 longitudinal load increases, the fatigue decreases. Thus, when the load ou the 

 wire is doubled the decrease in tlie maximum fatigue is 65 per cent, for the 

 high rigidity, 51 per cent, for the middle value of rigidity, and 31 percent, 

 for the lowest rigidity. 



In order to show at a glance how the fatigue of nickel wire varies or 

 changes with the rigidity, and also to show the rate of fatigue, the results 

 obtained witli the smallest load in each of tlie three eases are here, in fig. 1, 

 put in the form of curves. Tlie abscissae represent the time in minutes tliat 

 the alternating magnetic field was applied, and the ordinates represent the 

 corresponding fatigue. The top curve is that obtained with the wire of 

 greatest rigidity, and the lowest curve with the wire of least rigidity. 



4 6 



Minutes 



The limits between which the nickel wire is and is not sensitive to fatigue 



