Elastic Waves, with Seismological Applications. 83 



1. Condensational-raref actional Wave Incident on the Interface 

 of two Elastic Solids; of which the Rigidities and Com- 

 pressibilities are equal and the Densities as 1 to 2. 



(1) Incident Wave in the less dense medium. 



9. 



A. 



A. 



6'. 



A'. 



0. 



B v 



0'. 



B'. 



0° 



1 



•03 





•97 















14° 2' 



1 



024 



10° 



•970 



8° 



•004 



5° 



•003 



26° 34' 



1 



•010 



18° 



•958 



15° 



■016 



11° 



•on 



45° 



I 



•001 



30° 



•930 



24° 



•039 



17° 



•029 



59° 2' 



1 



•on 



37° 



•881 



30° 



•062 



21° 



■047 



73° 18' 



1 



■1-28 



43° 



•743 



34° 



•071 



23° 



•055 



81° 17' 



1 



•511 



45° 



•410 



35° 



•044 



24° 



•035 



(2) Incident Wave in the denser medium. 



0. 



A. 



A,. 



0'. A'. 



<p. 



B v 



f- 



B'. 



0° 



1 



•03 



•97 











11° 2' 



1 



•025 



20° -966 



8 



•004 



11° 



•006 



: 26° 34' 



1 



015 



39° -939 



15° 



•018 



21° 



■025 



42° 16' 



1 



•020 



72° -767 



23° 



•093 



33° 



•119 



45° 



1 



•444 



90° 



24° 



•244 



35° 



•311 



45° 17' 



1 



•403 



imaginary. 



24° 



•237 



36° 



•302 



48° 



1 



•514 





25° 



•210 



37° 



•266 



59° 2' 



1 



■631 





30° 



•144 



44° 



•167 



73° 18' 



1 



•825 



, 



34° 



•084 



52° 



•089 



84° 17' 



1 



•936 



" 



35° 



•033 



54° 



•032 



The chief points to be noted here are : — (a) The manner in 

 which the energy of the reflected condensational waves, always 

 small at the lower incidences, passes through a minimum 

 value, and the suddenness with which, in the second case, it 

 increases when the angle of total reflexion is reached ; (b) 

 the simultaneous rapid increase, in the region of this critical 

 angle, of the energy of the derivative distortional waves ; (c) 

 the fairly large values of these distortional waves when the 

 condensational wave is incident on the denser medium, more 

 than half the energy taking this form for incidences in the 

 neighbourhood of 45°. 



G2 



