SEISMIC METHODS 937 



2,404,786 Issued July 30, 1946. L. G. Bostwick. "Moisture Control in an Electro- 

 mechanical Device." 



2.405.226 Issued Aug. 6, 1946. W. P. Mason. "Low Frequency Projector or 

 Hydrophone." 



2.405.227 Issued Aug. 6, 1946. W. P. Mason. "Geometrical Instrument." 

 2,406,014 Issued Aug. 20, 1946. W. R. Harry. "System for Locating the Source 



of an Explosion Wave." 

 2,406,391 Issued Aug. 27, 1946. W. P. Mason. "Compressional Wave Directional, 



Prismatic, and Focusing System." 

 2,407,363 Issued Sept. 10, 1946. W. H. Bussey. "Electrical Apparatus." 

 2,407,662 Issued Sept. 17, 1946. H.M.Hart. "Method and Apparatus for Submarine 



Signaling." 

 2,408,001 Issued Sept. 24, 1946. E. J. Shimek and W. B. Hemphill. "Gain-Control 



System for Seismic Amplifiers." 

 2,408,125 Issued Sept. 24, 1946. H. J. Rolfes. "Means of Safeguarding Electric 



Igniters of Blasting Detonators against Accidental Firing." 

 2,408,189 Issued Sept. 24, 1946. A. W. Baker. "Waterproof Explosive Cartridge." 

 2,416,321 Issued Feb. 25, 1947. E. T. Jones. "Automatic Volume Control in Voice 



Frequency Circuits." 

 2,417,077 Issued March 11, 1947. H. Hoover, Jr. "Seismometer." 

 2,418,953 Issued April 15, 1947. R. W. Raitt. "Transducing System." 

 2,420,025 Issued May 6, 1947. W. W. Young. "Vibration Recorder." 

 2,420,868 Issued May 20, 1947. M. G. Crosby. "Diversity Combining Circuit." 



2.423.970 Issued July 15, 1947. L. W. Gardner. "Geophone Polarity Indicator." 

 2,424,724 Issued July 29, 1947. J. F. Folk. "Position-Dampened Seismometer." 

 2,428,168 Issued Sept. 30, 1947. G. B. Loper. "Seismic-Wave Detector." 

 2,431,307 Issued Nov. 25, 1947. P. K. Chatterjea and C. T. Scully. "Thermionic 



Valve Amplifier." 



2,431,600 Is_sued_ Nov. 25. 1947. A. Wolf. "Seismic Exploration with Control of 

 Directional Sensitivity." 



2,435,903 Issued Feb. 10, 1948. O. F. Ritzmann. "Method and Apparatus for Ex- 

 hibiting Seismograph Signals." 



2,438,217 Issued March 23, 1948. C. H. Johnson. "Method for Elimination of 

 Periodic Stray Signals from Seismic Signals." 



2,438,526 Issued March 30, 1948. C. H. Waterman. "System for Determining the 

 Direction of a Source of Sound." 



2.438.755 Issued March 30, 1948. E. W. Larsen. "Vibrating Apparatus." 



2.438.756 Issued March 30, 1948. E. W. Larsen. "Vibrating Apparatus." 



2.440.971 Issued May 4, 1948. E. M. Palmer. "Seismograph Recording Apparatus." 

 2,444,676 Issued July 6, 1948. F. W. Roberts and R. C. Curtis. "Sound Recording 



and Reproducing Control System." 

 2,445,014 Issued July 13, 1948. L. Wolff. "Vibratory Mechanical System." 

 2,446,195 Issued August 8, 1948. S. L. Shive. "Tester for Electrical Shieldings." 

 2,446,818 Issued August 10, 1948. S. Flam. "Vibrator." 

 2,448,812 Issued Sept. 7, 1948. J. Lemire. "Electric Timing Motor." 

 2,449,921 Issued Sept. 21, 1948. A. Wolf. "Seismic Method of Locating Faults." 

 2,450,352 Issued Sept. 28, 1948. R. G. Piety. "Seismic Wave Correction Means 



and Method." 

 2,450,366 Issued Sept. 28, 1948. J. D. Williams. "Apparatus and Method of Seis- 



mographic Exploration Shooting." 

 2,456,401 Issued Dec. 14, 1948. R. P. Gilmore. "Interference Eliminator for Seismic 



Recording Systems." 

 2,457,214 Issued Dec. 28, 1948. H. G. Doll and G. K. Miller. "Recording Device." 

 2,457,712 Issued Dec. 28, 1948. H. F. Olson and J. Preston. "Method and Apparatus 



for Noise Control of Reproduced Sound." 

 2,461,005 Issued February 8, 1949. G. C. Southworth. "Ultra High Frequency Trans- 

 mission." 

 2,462,764 Issued February 22, 1949. W. J. O'Brien. "Navigation System." 

 2,463,474 Issued March 1, 1949. H. G. Busignies. "Air Navigation System." 

 2,463,476 Issued March 1, 1949. H. G. Busignies. "Radio Navigation System." 

 2,461,187 Issued February 8, 1949. W. Steinmann. "Direction Finding Apparatus." 

 2,461,213 Issued February 8, 1949. W. D. Herschberger. "Distance Measuring 



Device." 



