xxx Proceedings, &c, for 1868. 



from submarine disturbance near the shore. It might also happen 

 from the breaking-down of the submarine embankments, for which 

 great force would not be required. In support of this he would 

 remark that soundings taken after the appearance of such wave, had 

 differed materially from those taken previously on the same spot. 



Professor Wilson said the discussion on this subject opened up 

 the whole theory of the eruption of volcanoes. It must be allowed 

 that molten lava was beneath the earth, and the hydrostatic power 

 beneath the molten lava necessary to cause these eruptions must be 

 of different degrees of force to act upon the different materials. 

 For instance, Vesuvius was of a sandy character, while in South 

 America many of the mountains were of solid stone, and the power 

 required to upheave these would be immense. It was true that hot 

 lava coming into contact with water would explode, but that was 

 the consequence and not the cause. 



Mr. D. Eees inquired if there was any other mode of 

 accounting for the transmission of the wave than that given by 

 Professor Wilson; The President could not say, and referred to 

 some observations by Dr. Hector on the subject. 



Professor Wilson explained, by a diagram, the motions of a wave 

 at the velocity indicated, 200 miles an hour, or fifty miles in 

 fifteen minutes, and showed that from the gentle character of the 

 slope it would be almost imperceptible to a ship crossing its track, 

 while the power at the point where it touched the land would be 

 very great. 



Some other discussion ensued. 



Mr. William Walker inquired whether the formation of a single 

 wave was not a physical impossibility. W 7 aves were formed by wind 

 and other forces ; when the wind ceased the waves subsided. The 

 tremulous motion felt by ships might be attributed to electricity, 

 the copper bottoms of which formed an excellent conductor. 



Professor Wilson said he had been informed that when the 

 " Royal George" was blown up, the shock w.as felt by a boat before 

 the column of water consequent on the explosion was seen ; and 

 Mr. Ellery related a similar case occurring on the Saltwater River 

 when he, with others, were testing a torpedo. The shock felt was 

 that of a blow, not of a vibrating motion usually attendant upon 

 electrical concussion. 



Mr. Walker contended that the shock was due to electricity : and 

 after a further discussion, in which the action of the Gymnotus or 

 Electric Eel formed the principal topic, the meeting adjourned. 



(Signed) Robt. L. J. Ellery .- 



November 9, 1868. 



