270 SEE— TEMPERATURE, SECULAR COOLING fApril 20, 



served in the same region after the earthquake which shook ^gion, 

 December 26, 1861, may possibly have been due to the settlement 

 of the alluvium, but it is much more probable that it arose from a 

 sinking of the crust along the line of a hidden fault, similar to that 

 which so severely rent the ground under Bura in 373 B.C. 



It is usually stated that Bura was covered by the sea like Helike, 

 but some of the ancient authors correctly imply that the ruin was 

 mainly due to the opening of fissures of the earth, which caused the 

 houses to be engulfed. Others say that it was also covered by the 

 sea, but both here and at Helike some objects remained above the 

 water. Bura, however, was built on a hill and ruins of it are still 

 extant at considerable elevation above the sea level. 



The land which sank when Helike was submerged beneath the 

 waves was evidently similar to that now seen along the southern 

 shore of the gulf of Corinth. A railroad now traverses this shore 

 alrnost the entire length of the gulf. While on a visit to Delphi 

 early in April, 1891, the writer crossed the gulf in a sail boat, and 

 took the train for Olympia near this ancient site of Helike and 

 Bura. The lay of the land is gentle and nowhere is the ascent 

 other than very gradual. The mountains of Arcadia are quite a 

 distance away, but usually visible to the traveler. From my own 

 observations of the southern shore of the gulf, along the region 

 where Helike now lies beneath the waves, I feel sure that the land 

 of this entire region is too solid to experience appreciable settling 

 under the shaking of an earthquake. What then was the cause of 

 the disaster of 373 B.C. ? 



In the paper on the cause of earthquakes, we have seen that in 

 world-shaking seismic disturbances lava moves beneath the crust, 

 and usually is expelled from under the bed of the sea. After the 

 crust is thus undermined, the sea bottom frequently subsides, and 

 the sinking of the bed of the sea draws the water away from the 

 shore and causes the seismic sea waves. The gulf of Corinth is a 

 sea trough, with high mountains on both sides; and in 373 B.C. 

 lava was expelled from under it and pushed under the mountains 

 to the north or south — most likely under the Arcadian mountains 

 to the south; and after the lava was expelled the bed of the 

 trough sank down, carrying with it the shores on which Helike 

 stood. 



