STRAIN ON THE PHYSICAL PROPERTIES OF MATTER. 
837 
being very low for nickel, so that with this metal it is difficult to avoid “ elastic 
fatigue.” 
10. Mechanical shocks and rapid fluctuations of tempeiature beyond certain limits 
may increase very considerably the internal friction, and, though to a much less 
extent, diminish the torsional elasticity. 
11. The logarithmic decrement is independent both of the length and of the 
diameter of the wire. 
