THE JAMAICA EAETHQUAKE 



399 



Fig. 15. Nearer View of Submergence at Port Royal, looking south. Mostot the area 

 now covered by water in the photograph was formerly land. 



or so of the cable had to be abandoned. The preliminary tremors were 

 heard before being felt and probably were slower than sound-waves. 

 With the increase of speed that comes with the augmentation of in- 

 tensity of earthquakes, it is probable that the rate of the major vibra- 

 tions was about ten thousand feet per second. 



As has been previously stated the shock was a double one; the 

 first climax apparently came from the west, while the second one, less 

 disputive and more undulating in its character, apparently came more 

 from the southward of Kingston. These two directions of vibration 

 resulted in an almost universal gyratory movement of columns, statues, 

 piers, sections of brick chimneys, and even of buildings, in a counter- 

 clockwise (Fig. 10) fashion. 



Geologically, earthquakes often are not very important. In the 

 case of the earthquake at Jamaica, however, there apparently was a 



Fig. 10. Twisting of Rails and Tilting of Buildings in Victoria Battery, 



Port^Royal, by Subsidence. 



