632 EXPLORATION GEOPHYSICS 



672,309 Issued Apr. 16, 1901. Fred Harvey Brown. "Process of Locating Metallic 



Minerals." 

 681,654 Issued Aug. 27, 1901. A. F. McClatchey. "Electric Prospecting Apparatus." 

 686,632 Issued Nov. 12, 1901. A. F. McClatchey. "Apparatus for Locating Minerals, 



Metals, Ores, Etc." 

 689,849 Issued Dec. 31, 1901. Fred Harvey Brown. "Apparatus for Detecting and 



Locating Metallic Ores, Minerals, Etc." 

 714,775 Issued Dec. 2, 1902. Fred Harvey Brown. "Electrical Process of Locating 



Running Water in the Earth." 

 727,077 Issued May 5, 1903. Fred Harvey Brown. "Apparatus for Locating Metals, 



Minerals, Buried Treasures, etc., without Digging." 

 736,411 Issued Aug. 18, 1903. George I. Leonard. "Method of Locating Minerals." 

 792,025 Issued June 13, 1905. John Hamilton, Jr. "Means for Protecting Electric 



Circuits." 

 817,736 Issued April 10, 1906. Leo_ Daft and Alfred Williams. "Apparatus for 



Detecting and Localizing Mineral Deposits." 

 840,018 Issued Jan. 1, 1907. Max Von Schultz. "Apparatus for Searching of 



Sunken Bodies." 

 841,188 Issued Jan. 15, 1907. Adolf Schmidt. "Device for Detecting Subterranean 



Waters." 

 1,045,572 Issued Nov. 26, 1912. Nils D. Levin. "Switch and Connecting Device for 



Electric Conductors." 



1.045.575 Issued Nov. 26, 1912. Heinrich Lowy. "Method of Locating Subterranean 

 Strata." 



1,092,065 Issued Mar. 31, 1914. Heinrich Lowy. "Method for Ascertaining the 



Nature of Subterranean Strata." 

 1,126,027 Issued Jan. 26, 1915. Max Jullig. "Apparatus for Detecting Pipe-Leads 



or Other Metallic Masses Embedded in Masonry." 

 1,163,469 Issued Dec. 7, 1915. Conrad Schlumberger. "Location of Ores in the 



Subsoil." 

 1,212,763 Issued Jan. 16, 1917. Frank J. Gregory. "Device for Locating Concealed 



Conductors." 

 1.237,559 Issued Aug. 21, 1917. Shiro Sano. "Balancer." 



1,241,197 Issued Sept. 25, 1917. Harry R. Conklin. "Method & Apparatus for Deter- 

 mining Subterraneous Conductors." 

 1,241,963 Issued Oct. 2, 1917. Edward H. Grove. "Electrical Means for Locating 



Concealed Pipes." 

 1,248,380 Issued Nov. 27, 1917. Rupert Nelson. "Method of and Apparatus for De- 

 tecting the Presence of Ore Deposits in the Earth." 

 1,287,251 Issued Dec. 10, 1918. William S. Darley. "Method for Locating Concealed 



Conductors." 

 1,297,929 Issued Mar. 18, 1919. John B. Taylor. "Differentially-Connected Exploring 



Coils." 

 1,325,554 Issued Dec. 23, 1919. Wendell L. Carlson and Earl C. Hanson. "Means 



for Locating Ore Bodies by Audio-Frequency Currents." 

 1,334,118 Issued Mar. 16, 1920. Chester W. Rice. "System for Amplification of 



Small Currents." 

 1,419,674 Issued June 13, 1922. Harry W. Hitchcock. "Electrical Measuring 



Apparatus." 

 1,461,492 Issued July 10, 1923. John F. Moody. "Electrical Testing Instrument." 

 1,465,352 Issued Aug. 21, 1923. George G. Dobson. "Electrical Testing System." 

 1,471,383 Issued Oct. 23, 1923. Alva B. Clark. "Method of and Aleans for Measuring 



Unbalance." 

 1,475,240 Issued Nov. 27, 1923. Harold S. Osborne. "Low-Frequency Measuring 



Device." 

 1,491,900 Issued April 29, 1924. Daniel G. Chilson. "Process of and Device for 



Locating Ore." 

 1,492,300 Issued Apr. 29, 1924. Heinrich Lowy. "Means for Electroaviatic Proof 



and Measuring of the Distance of Electric Conductive Bodies." 

 1,496,786 Issued June 10, 1924. William T. Shackelton. "Portable Impedance Bridge." 



1.501.576 Issued July 15, 1924. Donald F. Whiting. "Electrical Testing System." 

 1,507,016 Issued Sept. 2, 1924. Lee de Forest. "Radiosignaling System." 



