(fyapt&i 26 



SEISMIC 



John C. Hollister 



and 



W. P. Hasbrouck 



The first proposal to obtain subsurface geological information by recording 

 the seismic impulses from an artificial earthquake was made by Robert Mallet 

 to the Royal Irish Academy in 1846 (Weatherby, 1940). In the next two years, 

 he developed a mercury -bowl seismoscope and measured the velocity of artificially 

 produced earth waves through the granites of Dalkey Island. According to De- 

 Golyer (1935), there is little doubt that Mallet discovered the seismic refraction 

 method. 



The large explosive charge studies of General H. L. Abbott in 1876, the 

 the falling weight or "thumper" of Milne and Gray in 1885, the theoretical studies 

 of C. G. Knott in 1899 and of Wiechert and Zoeppritz in 1907, and the nine- 

 mechanical-seismograph profile of 0. Hecker in 1900 constituted significant 

 steps in the early progress of the seismic methods. 



The first use of reflected energy was made in 1914 by Reginald Fessenden 

 while using his Sonic Sounder to find ocean depths. Three years later, W. P. 

 Haseman and J. C. Karcher of the National Bureau of Standards considered 

 the feasibility of using reflected seismic waves in the location of potential oil 

 structures. Preliminary experiments in a rock quarry in Washington, D. C. 

 resulted in the first successful reflection seismogram. In 1921 with D. W. Ohern, 

 Irving Perrine, and W. C. Kite, Haseman and Karcher set out to test the re- 

 flection method. After initial failure on what was later to be recoginzed as the 



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