US2427421A
|
|
Apparatus and method for making and analyzing geophysical records
|
US2261563A
|
|
System for measuring earth conductivity
|
US2337414A
|
|
Method and apparatus for testing lubricating oils
|
US2051153A
|
|
Method and apparatus for recording elastic waves
|
US1981665A
|
|
Earth bore surveying instrument
|
US1836397A
|
|
Method of and apparatus for locating the direction of sound
|
US1782445A
|
|
System and method for geophysical exploration
|
US1902184A
|
|
Vibration sensitive system
|
US1780567A
|
|
Method and apparatus for recording explosive shocks
|
US1902183A
|
|
System for receiving and recording vibrations
|
US1919480A
|
|
Translating device
|
US1867098A
|
|
Method and means for radiating vibratory mechanical impulses into solids, liquids, and the like
|
US1776009A
|
|
Apparatus for transforming mechanical vibrations into electrical fluctuations
|
US1827371A
|
|
Method and means for geological explorations
|
US1499551A
|
|
Alternating-current system
|