34 Dr. C. Davison on the Method of Determining 



Station. 



Mean Depth in Fathoms obtained from 



Velocity of Sea-waye. 



Soun dings. 



Galle 



2120 

 1445 

 1880 

 1700 

 1700 

 1400 

 1820 

 1580 

 1770 

 1650 

 1710 

 1770 

 2430 

 2120 

 2245 

 2040 

 2660 

 2520 

 2050 

 2640 

 2420 

 2640 



2400 



2380 



2300 



2300 



2200 



2150 



2100 



2300 



2300 



1700 



2150 



2150 



2600? 



2300? 



2300? 



2300? 



2300 



2300 



2300 



2300 



2300 



2300 



Colombo 



*Madras 





*Dublat 

















*Port AKred 



*Table Bay 

















Thus in every case, except along the paths to the six 

 French and English stations, the mean depth obtained from 

 the velocity of the sea-waves is less than that obtained from 

 the soundings. Capt. Wharton does not, however, regard 

 the evidence afforded by any of the six gauges as conclusive. 

 The disturbance in all of them is very slight ; though, on the 

 other hand, "looking at them collectively, and seeing the fair 

 accordance of the speed of the waves — which would travel on 

 the same course — the evidence is strongly in favour of the 

 disturbances on these gauges being the effect of one and the 

 same cause, and one which originated at a great distance." 



Similar calculations have been made from the waves which 

 accompanied the Iquique earthquake of May 9, 1877 f. The 

 disagreement between the mean depths calculated by Dr. 

 G-einitz and Prof. Milne is chiefly due to the different positions 

 of the origin assigned by them to the sea-waves. The values 



t Dr. E. Geinitz, " Das Erdbeben von Iquique am 9 Mai, 1877, und die 

 durch dasselbe verursachte Erdbebennuth in Grossen Ocean," Nova Acta 

 der Ksl. Leop.-Carol.-Deutschen Akademie der Naturforscher, Bd zl. 

 1878, pp. 385-444. 



Prof. J. Milne, " The Peruvian Earthquake of May 9th, 1877." Japan 

 Seismol. Soc. Trans, vol. ii. 1880, pp. 50-96. Also * Earthquakes and 

 other Earth Movements,' 1886, pp. 182-186. 



