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ILLINOIS ACADEMY OF SCIENCE. 



eight daily and weekly papers, and upon fifty-five letters from 

 editors of newspapers. Information has been received from about 

 150 localities in and about the affected area. 



The distribution of intensities in an earthquake such as that 

 which occurred on January 2 is conveniently studied by the 

 so-called Rossi-Forel scale of intensity. According to this scale, 

 intensities are denoted increasingly by the numerals from one to 

 ten. The scale is not often seen in print, and since the author has 

 made some additions to the scale, it has been inserted at the end 

 of this paper. 



The author believes that the data collected concerning this 

 earthquake are sufficiently complete to determine with a fair 

 degree of accuracy the intensities at about ninety-five cities. At 

 thirty-five of these cities the disturbance is described as being 

 "not noticed," while for the remaining sixty the accounts are 

 more or less complete. The following isoseismal chart of the 

 earthquake is based upon the intensities as determined for these 

 cities according to the Rossi-Forel scale. 



It will be seen on the accompanying map that the intensities 

 vary from one to six. The general appearance of the isoseismal 



Figure 1. Map of earthquake of January 2, 1912. Full lines = isoseis- 

 mals of January 3, 1912 earthquake. Broken lines=isoseismals of May 

 26, 1909 earthquake. 



