142. . EARTHQUAKES. 



head of a monstrous catfish (Namadzu), which by its writh- 

 ings causes the shakings so often felt in this part of the 

 world.^ 



Prof. D. S. Martin, writing on the earthquake of New 

 England in 1874, says that it was felt at four points ; it 

 was felt in the heart of Brooklyn all within a circle of 

 half a mile across ; ' and this fact would suggest that a 

 ridge of rock perhaps approaches the surface at that 

 point, though none is known to appear.' ^ 



The subject of special districts, which are more or less 

 protected from severe shakings, will be again referred to, 

 and it will be seen that after a seismic survey has been 

 made even of a country like Japan, where there are on 

 the average at least two earthquakes per day, it is possible 

 to choose a place to build in as free from earthquakes as 

 Great Britain. 



General examples of earthquake effects. — The fol- 

 lowing examples of earthquake effects are drawn from 

 Mallet's account of the Neapolitan earthquake of 1857. 



At a town called Polla there was great destruction. 

 Judging from the fissures in the parts that remained 

 standing it seemed that the emergence of the shock had 

 been more vertical in the upper part of the town than in 

 the lower, proving that whatever had been the angle 

 below, the hill had itself vibrated, which, being horizontal, 

 had modified the angle of the fissures. 



Diano suffered but little, partly because it was well 

 built, and partly on account of its situation, which was 

 such that before the shock reached it the disturbance 

 had to pass from beds of clay into nearly vertically placed- 

 beds of limestone. Also a great portion of the shock was 

 cut off by the Vallone del Eaccio to the north and north- 



1 See chapter ' Causes of Earthquakes ' for details of this myth. 



2 Am. Jou. Set. vol. X. p. 191. 



