1116 EXPLORATION GEOPHYSICS 



2,165,013 Issued July 4, 1939. C. Schlumberger. "Method and Apparatus for 

 Identifying the Nature of the Formations in a Bore Hole." 



2,165,213 Issued July 11, 1939. L. W. Blau and L. Statham. "Electrical Transient 

 Well Logging." 



2,167,066 Issued July 25, 1939. D. W. Elliott. "Locating Water Strata in Oil Wells." 



2,167,630 Issued July 25, 1939. C. B. Bazzoni and Jos. Razek. "Electrical Prospecting 

 Methods and Apparatus." 



2,170,857 Issued Aug. 29, 1939. R. D. Elliott. "Recording Apparatus and Method." 



2,174,638 Issued Oct. 3, 1939. C. Schlumberger. "Method and Apparatus for Elec- 

 trical Survey of the Formations Cut by a Bore Hole." 



2,176,169 Issued Oct. 17, 1939. H. G. Doll. "Method and Arrangement for Deter- 

 mining the Direction and Value of the Dip of Beds Cut by a Bore Hole." 



2,183,565 Issued Dec. 19, 1939. P. F. Hawley. "Two-well Method of Electrical 

 Logging and Apparatus Therefor." 



2,184,338 Issued Dec. 26, 1939. G. H. Ennis. "Method of Apparatus for Locating 

 Water Leakages in Wells." 



2,189,900 Issued Feb. 13, 1940. David G. Hawthorne & John E. Owen. "Drill Stem 

 Circuit Tester." 



2,190,686 Issued Feb. 20, 1940. L. B. Slichter. "Mineral Exploration." 



2.191.119 Issued Feb. 20, 1940. Conrad Schlumberger. "Method and Apparatus for 

 Surveying the Formations Traversed by a Bore Hole." 



2.191.120 Issued Feb. 20, 1940. L. B. Slichter. "Method of Geological Survey." 



2.191.121 Issued Feb. 20, 1940. L. B. Slichter. "Geological Surveying Apparatus." 

 2,197,493 Issued April 16, 1940. L. G. Ellis and J. W. Millington. "Electrical Pros- 

 pecting Apparatus." 



2,199,367 Issued April 30, 1940. L. F. Athy and H. R. Prescott. "Method of Logging 



Bore Holes." 

 2,199,705 Issued May 7, 1940. J. C. Karcher. "Apparatus for Making Electrical 



Surveys of Bore Holes." 

 2,202,656 Issued May 28, 1940. C. J. Haynes. "Well-Logging Electrode." 



2.206.863 Issued July 9, 1940. R. T. Cloud. "Electrical Logging of Earth Formations." 



2.206.864 Issued July 9, 1940. R. T. Cloud. "Electrical Logging of Earth Formations." 



2.206.890 Issued July 9, 1940. P. F. Hawley. "Electrical Logging of Wells." 



2.206.891 Issued July 9, 1940. P. F. Hawley. "Electrical Logging of Earth 

 Formations." 



2.206.892 Issued July 9, 1940. P. F. Hawley. "Electrical Logging of Earth 

 Formations." 



2.206.893 Issued July 9, 1940. P. F. Hawley. "Method and Apparatus for Logging 

 Wells." 



2.206.894 Issued July 9, 1940. D. Silverman. "Method and Apparatus for Logging 

 Wells." 



2.207.280 Issued July 9, 1940. L. F. Athy, et al. "Method of Electrical Logging." 



2.207.281 Issued July 9, 1940. L. F. Athy and H. R. Prescott. "Seismic Method of 

 Logging Bore Holes." 



2,210,795 Issued Aug. 6, 1940. R. T. Cloud. "Method and Apparatus for Electrical 

 Logging." 



2.211.124 Issued Aug. 13, 1940. J. J. Jakosky. "Method for Continuously Explonng 

 Bore Holes." 



2.211.125 Issued Aug'. 13, 1940. J. J. Jakosky. "Method and Apparatus for the Elec- 

 trical Exploration of the Subsurface." 



2.212.273 Issued Aug. 20, 1940. Oscar Martienssen. "Arrangement for Measuring 

 the Local Specific Resistance of Bore Hole Strata." 



2.212.274 Issued Aug. 20, 1940. Oscar Martienssen. "Method of Exploring the 

 Porosity of Geologic Strata Traversed by Bore Holes." 



2,214,786 Issued Sept. 17, 1940. B. P. Bishop. "Apparatus for Logging Holes while 

 Drilling." 



2,219,274 Issued Oct. 22, 1940. S. A. Scherbatskoy. "Well Survey Method and 

 Apparatus." 



2,220,070 Issued Nov. 5, 1940. C. B. Aiken. "Method of and Apparatus for Magneti- 

 cally Exploring Earth Strata." 



2,220,788 Issued Nov. 5, 1940. R. W. Lohman. "Method and Apparatus for Investi- 

 gating Subterranean Strata by Means of Electromagnetic Measurements." 



