EARTHQUAKES 



supposed. The displacement is rarely more than 

 five millimeters or two-tenths of an inch. A move- 

 ment of three-hundredths of an inch is quite per- 

 ceptible. The destruction caused by such slight 

 movements is due not so much to the amount of 

 displacement as to the time occupied in the dis- 

 placement. These statements regarding movement 

 do not relate to swinging or loose objects, however, 

 or to the displacements along faults or to the slip- 

 ping of unsupported banks of loose earth. 



"EARTHQUAKE WEATHER." One sometimes hears 

 the expression "earthquake weather," implying that 

 either the weather causes the earthquakes, or that 

 an approaching earthquake modifies and determines 

 the weather. But inasmuch as the weather is due 

 to atmospheric conditions, and as earthquakes are 

 produced by disturbances in the rocks of the earth's 

 crust, evidently the relations between them must 

 be very remote and certainly no such relations have 

 been apparent from personal observations. 



REFERENCES 



CARNEGIE INSTITUTION OF WASHINGTON, D. C. 

 1908-10. The California earthquake of April 18, 1906. Rep. 

 State Earthquake Investigation Commission, A. C. 

 Lawson, chairman; 2 vols., pis., maps, diagrams 

 and atlas. 

 DAVISON, C. 



1905. A study of recent earthquakes. (Walter Scott Publ. 



Co., London), 355 pp., illus. 

 DUTTON, C. E. 



1904. Earthquakes. (G. P. Putnams Sons, N. Y.), 314 pp., 



illus. 

 HOBBS, W. H. 



1907. Earthquakes. (D. Appleton & Co., N. Y.), xxx+336 



pp., 24 pis. 

 KNOTT, C. G. 



1908. The physics of earthquake phenomena. (Clarendon 



Press, Oxford), 283 pp., illus. 

 MILNE, J. 



1903. Earthquakes and other earth movements. (D. Apple- 

 ton & Co., New York), 376 pp., illus. 

 MONTESSUS DE BALLORE, COMTE DE. 



1907. La science s6ismologique. (A. Colin, Paris), 579 pp., 

 illus. 



WALKER, G. W. 



1913. Modern Seismology. (Longmans, Green & Co., N. 

 Y.), 88 pp., 12 pis. 



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