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POPULAR SCIENCE MONTHLY 



Fig. 8, a. East and West Gable Ends destroyed by Shock. 



From the data available, the dependence of earthquakes in intensity 

 upon topography is well emphasized. Loosely compacted fringing and 

 alluvial plains extended the intensity farther than the more compact 

 and elastic mountain regions. Not only do these less elastic plains 

 give a greater amplitude to the waves and cause greater destruction, 

 but apparently the earth-waves are affected by plains indented in hills 

 as sea-waves change their direction in entering the arm of a bay. The 

 arrows (Fig. 1, a) indicate generally the direction of the wave motion. 

 In the middle of the Hope Eiver Valley at Mona Plantation an ob- 

 server noticed the motion pass him and then saw the landslide occur 

 at the mouth of the river to the southward. As the wave passed over 

 the cane-fields, a motion was observed similar to that produced in a 

 field of grain by the wind. The direction here was at right angles to 

 the path of the wave-motion only five miles away at Kingston, situ- 

 ated on the western slopes of Long Mountain. The motion approached 

 the island from the soutlnvest, changing on the land its direction and 

 intensity with the change in the nature of the material through which 

 it passed. In the lower part of the city of Kingston the path of the 

 movement was well marked by the overthrowing of walls, piers, statues, 

 monuments, large chimneys and a similar movement toward the east of 

 even large marble slabs covering graves (Figs. 3-9). Northward from 

 the city the motion appeared to come more from the south, and the 

 northern walls showed the greatest damage; and westward, the path of 

 motion appeared to swing so that it came from Kingston. The absence 

 of any large buildings, away from the villages and cities, made the plot- 

 ting of directions rather difficult, for the lightly-built mud-wattled huts 

 were not affected by the shock and tests by hearing are very unreliable. 

 But there was a general diminution in intensity away from Kingston; 



