ii6 



A. A. MICEELSON 



It is estimated that the errors in the ampHtude ratios are under 

 I per cent. The phase acceleration is probably correct to within 

 0^03, but is so small as to leave some doubt as to whether or not 

 it is real. 



The disagreement between the E.-W. and N.-S. directions has 

 been interpreted by Hecker, who found a similar difference, as 



14 16 



24 26 



Fig. 15.— E.-W. Mean of observations of diurnal Lunar tide, 

 observed values ; full curve, o . 7 of calculated. 



Dotted curve, 



indicating an actual difference in the earth's rigidity in the E.-W. 

 and N.-S. directions. 



Schweydar agrees with A. E. H. Love in attributing the differ- 

 ence to the effect of ocean tides, and shows on the assumption of an 

 ocean covering the earth uniformly to a depth of 5000 meters that 

 the tides have the effect of increasing the elastic earth tides, so that 

 the ratio of the observed amplitudes to the theoretical is diminished 

 by something like 40 per cent. 



The mean values of the ratio adopted by Schweydar are 0.61 

 for E.-W. and 0.46 for N.-S., which should therefore be increased 



