634 



EXPLORATION GEOPHYSICS 



1,766,378 



1,775,502 



1,775,686 



1,791,933 

 1,792,910 



1,794,666 



1,797,545 

 1,803,405 



1,805,900 

 1,808,397 



1,811,547 

 1,812,392 

 1,813,845 

 1,816,958 

 1,818,331 

 1,820,953 

 1,826,736 

 1,832,969 

 1,838,371 

 1,839,732 



1,840,635 

 1,841,376 



1,841,975 



1,841,976 



1,841,977 



1,842,361 



1,842,362 



1,843,407 

 1,847,127 

 1,848,134 

 1,859,005 



1,861,052 

 1,863,542 



1,864,024 

 1,876,324 



Issued June 24, 1930. Edward H. Guilford. "Method of Locating Unknown 

 Conductive Bodies." 



Issued Sept. 9, 1930. Manfred Schleicher, Dieter Albrecht, Wilhelm Gaarz 

 and Georg Keinath. "Apparatus for Measuring Earth Resistances." 

 Issued Sept. 16, 1930. Joseph W. Milnor. "Measuring Resistance of Ground 

 Connections." 



Issued Feb. 10, 1931. Emil E. Mueser. "Electrical Prospecting." 

 Issued Feb. 17, 1931. John J. Jakosky. "Method and Apparatus for Lo- 

 cating Conductive Bodies." 



Issued Mar. 3, 1931. E. S. Bieler & H. G. Watson. "Apparatus for Use 

 in Discovering and Determining Ore Bodies." 

 Issued Mar. 24, 1931. William B. Churcher. "Vehicle Wheel." 

 Issued May 5, 1931. Norman H. Ricker. Electromagnetic Method of Under- 

 ground Exploration." 



Issued May 19, 1931. R. Ambronn. "Method of Exploring the Subsoil." 

 Issued June 2, 1931. L. C. Billotte, Revere & E. Lipson. "Method and 

 Apparatus for Locating Deposits of Oil, Gas and other Dielectric Sub- 

 terranean Bodies." 



Issued June 23, 1931. John J. Jakosky. "Method and Apparatus for 

 Locating Unknown Conductive Bodies." 



Issued June 30, 1931. T. Zuschlag. "Method of and Apparatus for Locating 

 Terrestrial Conducting Bodies." 



Oliver H. Gish. "Apparatus for the Study of the 



Alva B. Clark & Fred H. Best. "Transmission 



"Method for Determining the 



Lindblom. "Method and 



"Alter- 



E. Miller. "Process for Determining 

 a Different Electrical Conductivity 



Issued July 7, 1931 

 Earth's Crust." 

 Issued Aug. 4, 1931. 

 Measuring System." 



Issued Aug. 11, 1931. John J. Jakosky 

 Character of Ore Bodies." 



Issued Sept. 1, 1931. K. Sundberg and E. D 

 Apparatus for Subsoil Investigating." 



Issued Oct. 13, 1931. Alder F. Connery and Ronald S. Wisehart 

 nating Current Balance Indicator." 



Issued Nov. 24, 1931. Paul G. Edwards and Harold W. Herrington. 

 "Testing System." 



Issued Dec. 29, 1931. Ralph W. Deardorff. "Electromagnetic Wave 

 Explorer." 



Issued Jan. 5, 1932. C. H. Beal and C 

 the Location of Substances having 

 from Surrounding Media." 

 Issued Jan. 12, 1932. Henry C. Parker, "Electrical Measuring Instrument." 

 Issued Jan. 19, 1932. Charles R. Nichols and Samuel H. Williston. "Elec- 

 trical Prospecting." 



Issued Jan. 19, 1932. Charles R. Nichols and Samuel H. Williston. "Elec- 

 trical Prospecting." 



Issued Jan. 19, 1932. C. R. Nichols and S. H. Williston. "Electrical 

 Prospecting." 



Issued Jan. 19, 1932. C. R. Nichols and S. H. Williston. "Electrical 

 Prospecting." 

 Issued Jan. 19, 1932. 

 Prospecting." 



Issued Jan. 19, 1932. C. R. Nichols and S. H. Williston. "Electrical 

 Prospecting." 

 Issued Feb. 2, 1932. 

 Issued Mar. 1, 1932. 

 Issued Mar. 8, 1932. 

 Issued May 17, 1932. 

 and Measuring Electromagnetic Fields.' 

 Issued May 31, 1932. William Dubilier. "Variometer." 

 Issued June 14, 1932. Charles R. Nichols and Samuel H. Williston. "Elec- 

 trical Prospecting." 



Issued June 21, 1932. Heinrich Lowy. "Method of Exploring Ground." 

 Issued Sept, 6, 1932, Stephen W. Borden. "Ground Resistance Meter." 



C. R. Nichols and S. H, Williston. "Electrical 



Karl Sundberg. "Underground Strata Prospecting." 

 Hans Mayer. "Electrical Testing System." 

 Kenneth B. Lambert. "Electrical Testing System.'' 

 Norman H. Ricker. "Means and Method of Observing 



