Determination of the coefficient of the loss of torsional couple due to the imperfectness of the arrangement. / 8
Elastic Yielding. / 16
General facts. / 16
Rate of the elastic yielding. / 19
Approximate expression for the elastic yielding. / 21
Limit of the elastic yielding. / 22
Effect of temperature. / 23
Modulus of rigidity in virgin piece. / 25
Hooke's law not related to hysteresis. / 25
Hysteresis. / 28
Elastic recovery. / 30
Multiplicity of the modulus of rigidity. / 33
No definite torsion associated with a given couple. / 33
No definite torsional gradient by passing through a given state. / 33
Neutral state and non-twisted state freed from couple. / 33
Neutralization of a twisted piece. / 34
Theories.
Time-lag due to inertia. / 37
Elastic yielding. / 38
Hysteresis due to elastic yielding. / 40
Expression for residual twist. / 41
Elastic recovery. / 42
Total amount of the elastic yielding at any stage after N reversals. / 43
Twist may increase with decreasing twisting couple. / 44
When the centre of symmetry of the cyclic process is fixed,the rate of twisting is greater for greater amplitude of the cycle than for the smaller. / 45
When the amplitude is given,the rate of untwisting is smaller for the cycle whose centre is more remote from the neutral state than for the other. / 46
Conclusions. / 50
Appendix.
Relation between the velocity of propagation and the amplitude of seismic waves. / 52
Deduced from the result of experiments. / 53
Deduced from the theory of elastic yielding. / 53
Summary: Disturbance of smallest amplitude travels quickest
tremors and principal shocks propagate not necessarily through different paths. / 56
Tables of Time-lag,Elastic yielding and Hysteresis-function. / 58