EARTHQUAKES IN GEOLOGY 



and tremblings for days, weeks, or months afterwards. 

 Some of these are of considerable force, though they do 

 not inflict the devastation of the principal earthquake. 

 The greatest earthquakes are not always those which 

 wreak the largest amount of destruction. Evidently an 

 earthquake, the centre of which is situated near a great 

 city, is more appalling in its effects than one which takes 

 place in some desert place like the steppes of Siberia. 

 Recent earthquakes in Italy and near San Francisco were 

 regarded as great earthquakes because they took place in 

 thickly populated neighbourhoods. In cities, writes Pro- 

 fessor W. H. Hobbs, to the rumbling of the earthquake 

 is quickly added the crash of falling masonry, and to this 

 succeeds an uncanny grey darkness as the air becomes 

 filled with the dust from broken bricks, mortar, and 

 plaster. ... In places the ground opens and swallows 

 the objects which lie upon it. Ponds are sucked down 

 and disappear, and great fountains of water gush out 

 and flood the country. During the New Madrid earth- 

 quakes of 1811 and 1812 water was shot upwards in 

 vertical sheets and carried to the tops of the highest 

 trees. Near Lake Baikal, during the earthquake on 

 January 26th, 1862, the surface of the steppe, over two 

 hundred square miles, was suddenly dropped; fountains 

 opened at many parts within the sunken area, and water 

 shot up to heights of twenty feet. The water gushed 

 also in great volume from the open wells, and where these 

 were tightly covered by wooden caps, their lids were shot 

 up into the air like corks from champagne bottles. On 

 the night of September 5th, 1896, during heavy earth- 



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