Improvements in or relating to apparatus for the complete determination of the direction and strengths of magnetic fields in particular of the natural magnetic field of the earth
GB340245A
Improved apparatus for the calibration and control of alternating current compensation apparatus
GB339964A
Improved process for investigating the geological structure of the sub-soil
US1897688A
Method of and apparatus for electric earth exploration
GB308256A
Improvements in processes of and devices for electrically exploring the ground by means of alternating currents of very low frequency
GB291025A
Improved apparatus for electrically exploring the ground or soil
GB279091A
Improvements in processes of explorating the ground by electricity
GB267501A
Improvements in apparatus for the exploration of the ground by alternating currents
US1936321A
Process of and device for detecting and measuring minimum accelerations
GB219437A
An electrical process for facilitating the discovery of mineral deposits
GB221845A
Improvements in or relating to apparatus for testing long bodies of material that can be magnetised
