362 POPULAR SCIENCE MONTHLY. 



MODERN STUDIES OF EARTHQUAKES. 



Br GEORG GERALAND. 



nnHE investigation of earthquakes, seismology, has become in the 

 -L- present day an independent subject of scientific interest. In 

 lands where earthquakes are frequent, as in Italy and Japan, seismic 

 observations have been officially systematized over the whole country, 

 with central and branch stations at which the work is never still. A 

 net of seismic observations of all nations is being more and more 

 closely woven over the whole earth, and there are yearly and monthly 

 collations of observations of even the slightest shocks. Seismic 

 literature is, therefore, nearly inexhaustible, and theory and praxis 

 are in constant vogue; in short, seismics has grown to be a separate 

 branch of science, and to demand independent treatment, calling for 

 the energy and labor of many students. What gives it so great im- 

 portance? What is the condition of our present knowledge and its 

 history? What will be reached in the future through the competi- 

 tion of the nations? These questions possess a high scientific as well 

 as culture-historical interest. We here attempt to answer them. 



The first really scientific description of an earthquake — that of 

 Lisbon — with its far-reaching accompanying phenomena, was the 

 work of the greatest contemporary thinker, Kant, and it is not too 

 much to say that his paper opened a new epoch in the knowledge of 

 earthquakes. That terrible event and the extreme terror which it 

 caused everywhere were followed in 1783 by the likewise extremely 

 destructive earthquake of Calabria. The attention of the people was 

 thus directed to this mysterious mighty activity of the earth, and was 

 kept especially lively in Italy, the country of Europe most subject 

 to earthquakes. The newly rising science of geology therefore found 

 in the last third of the last century in these phenomena a problem 

 of prominent importance. Geologists were the first to apply them- 

 selves to seismic studies, as the most widely current explanation of 

 the phenomena is still a geological one. The scientific interest of the 

 question prevailed over the practical. More attentive observation 

 was given to earthquakes, the accounts of them scattered through the 

 ancient chronicles were collated, and the already very numerous 

 seismic notes of great earthquake manifestations — such as those by 

 Hoff, Perry, Mallet, Volger, Fuchs, etc. — constituted a very im- 

 portant factor in the study. One of the earliest results of the inquiry 

 was to show that directly perceptible earthquakes are not perceptible 

 everywhere; that they are most common on the great upfoldings of 

 the earth's crust on the mountain chains, such as the Andes, Alps, 

 and Himalayas; and that, further, they are connected with the shores 



