262 



EARTHQUAKES. 



quakes which occurred in various parts of the world 

 between the years 1850 and 1857, made by Kluge, it is 

 found that both for the northern and southern hemi- 

 spheres the observations which were made during the night 

 generally exceed those which were made during the day. 





Number of Earthquakes 



In the Northern Hemisphere . 

 In the Southern Hemisphere . 



Day 

 938 

 292 



Night 

 1692 



357 



1 



In the northern hemisphere the greatest number were 

 observed between 10 p.m. and 12 p.m. (360 shocks), and 

 the fewest between 12 and 2 p.m. (139 shocks). In the 

 southern hemisphere, the greatest number were observed 

 at night between 12 and 1, and the smallest number 

 between 1 and 2 and 4 and 5 in the afternoon.^ These 

 distinctions, however, are less distinctly marked as we 

 approach the Equator. Schmidt found for the earth- 

 quakes of the Orient between 1774 and 1873, that shocks 

 had been most frequent about half-past two a.m., and less 

 frequent about 1 P.M. With regard to these conclusions, 

 which have been reached with much labour, we might be 

 inclined to think that they are partially to be explained 

 on the supposition that more observations are made during 

 the night than during the day — the personal experience 

 of residents in an earthquake country being, that many 

 earthquakes which occur during the day are passed by 

 unnoticed, whilst those which occur during the night are 

 recorded by thousands of observers. Such a view is cer- 

 tainly confirmed by the instrumental records obtained in 

 Japan. From 1872 to 1880 inclusive there were 261 

 shocks recorded, 132 of which occurred between the hours 

 of 6 P.M. and 6 a.m. 



Fuchs, Die Vulhai 



Ersclieinungen der Erde, p. 424. 



