1909.] THEIR CAUSES AND EFFECTS. 253 



like statues, columns and chimneys and had a noticeable effect on 



buildings. 



According to Professor Brown: 



The dip of the angling cracks at Kingston points to a locus of dis- 

 turbance much to the west of that city, while the lines of isoseismals indicate 

 the intensity area to be in the eastern half of Kingston. . . . The only 

 conclusion then is that the eastern end of the Liguanea plain was the 

 nearest area to the real epicenter that by nature of material would give 

 the greatest amplitude to the destructive epifocal waves. Further, the angle 

 of emergence at Kingston coordinated with the proximity of a probable 

 epicenter together with the limited area of disturbance indicates a shallow 

 origin of about three miles. 



As is demanded by theory and observed in fact the vibrations 

 increase in violence on passing from an elastic to an inelastic 

 medium — the destruction wrought in Messina, San Francisco and 

 other places has been worse in the sections built upon alluvial or 

 other loose soil than in those built upon rock, and Kingston was 

 entirely upon such loose material. The experiences of these and 

 other regions show that the destructiveness of an earthquake is not 

 necessarily greatest in the epifocal area. If the locus of disturbance 

 is in or under an elastic rock-mass and the shock is propagated into 

 a region of inelastic loose material, the destruction in the latter may 

 exceed that in the real epicenter. The fault which was the locus of 

 the San Francisco quake is some miles from the city. 



The shock of the Kingston earthquake was not sensible on the 

 island of Haiti to the east or on Grand Cayman to the west, but 

 Santiago de Cuba, 120 miles to the north, felt it slightly. This in- 

 dicates an ellipse as being the generalized form of curve for the 

 isoseismals, with the longer axis extending approximately north and 

 south. At Annotta and Buff Bays on the north shore of Jamaica, 

 opposite Kingston, the destruction wrought w^as almost as severe as 

 at the capital city. The inference is that renewed faulting along 

 north-south fault lines caused the earthquake. 



The building construction of Kingston was as bad as the founda- 

 tion upon which the city rested. Brick structures predominated, 

 but for the most part it was evident that the brick had been laid dry 

 in poor mortar. Such buildings collapsed under the shock. Those 

 that were properly put together withstood the quake better. Wooden 

 houses with good braces and well fastened together were not thrown 



