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POPULAR SCIENCE MONTHLY 



marine valley, to the west of which is a high mountain which does not 

 rise to the surface of the ocean. In the channel between the cape and 

 the submerged mountain the earthquake rift may be supposed to run. 

 In this channel numerous earthquake shocks have been recorded by 

 different passing vessels. If not itself a center of disturbance, it 

 records the line along which great disturbances have frequently passed. 



The rift struck the land at the mouth of Alder Creek, above Point 

 Arena. It crept over the hill as a deep furrow in the black, sticky 

 adobe, veering a little to left or right according to the resistance of the 

 soil, but always keeping in a straight line in its general direction. It 

 may be imagined as a sort of devouring dragon, leaving its trail on the 

 hills and destroying the works of man wherever it passes. It is hard 

 in following its course, not to think of it as endowed with a sort of 

 wicked life. Its movement is properly from north to south, but the 

 openyig of the great fault seems to have been really instantaneous. It 

 took place at 5 :13 a.m. and the waves lasted forty-seven seconds. It 

 may be noted in passing that the complication of the waves at any one 

 point was mainly due to the great length of the rift. A point imme- 

 diately near the crack felt mainly the first great shock, its wave and 

 the return wave. A point farther away felt the wave and its return 

 jolt, followed at once by waves from farther to the north and farther 

 to the south, these waves becoming more and more opposed to one an- 

 other. The waves would then augment, neutralize, override and other- 

 wise modify one another, the final result being the violent twisting 

 motion, the most remarkable trait of the latter portion of the earth- 

 quake in question. 



Coming over the first ridge, from the sea, the rift passed under the 

 long bridge over Alder Creek. The land on the west side of the bridge 



Point Arena. Picket fence was in one continuous line. Photograph shows short section 

 put in to fill up offset by land on the west side. 



