REPORT OF THE SECRETARY. 7 



on for a hundred years. We have learned that slow movements of 

 the land must precede many large earthquakes, and monuments are 

 now being set up in California to enable us to discover future move- 

 ments of the land and thus to anticipate future earthquakes. This, I 

 think, is the most important step so far taken toward the prediction 

 of earthquakes. 



COOPERATION. 



Seismological work is too large to be prosecuted successfully by the 

 universities, but requires some central office under government super- 

 vision to encourage theoretical and observational studies and to col- 

 lect and study information from all available sources. The various 

 departments of the Government could offer material help. The 

 Weather Bureau could furnish information regarding felt shocks 

 and could maintain seismographs at some of their stations. Post- 

 masters throughout the country could also report felt earthquakes. 

 The Coast and Geodetic Surve}' could maintain instruments and 

 adapt their surveys and tidal observations to the detection of slow 

 earth movements. The army could give information regarding 

 earthquakes felt at their outlying posts, the navy regarding 

 earthquakes felt at sea. The Geological Survey could furnish infor- 

 mation regarding the geological structure of earthquake regions. 



SEISMOLOGICAL CLEARING HOUSE AND FOREICN COOPERATION. 



The seismological laboratory would collect and study all this infor- 

 mation. It would serve as a clearing house for the whole country. 

 It would also be the link to connect seismological work in this country 

 with the work done in other parts of the world. Its director should 

 represent the United States in the International Seismological Asso- 

 ciation which this country has joined through the Department of 

 State. 



GOVERNMENT WORK IN FOREIGN COUNTRIES. 



Germany, Italy, Hungary, Eoumania, Bulgaria, and Japan have 

 maintained for some 3'ears offices for the collection and study of earth- 

 quake material. Chile and Mexico have recently established them. 

 The work in England is under the direction of the Ro} r al Society. 

 Many other countries maintain stations for seismological observa- 

 tions. This is the only important country subject to destructive 

 earthquakes whose government does not support the study of earth- 

 quakes. 



WORK OF THE LABORATORY. 



1. Collection and study of all information regarding earthquakes 

 in the United States and its possessions. The preparation of maps 

 showing the distribution of earthquakes and their relation to geo- 

 logical structure. 



