The experiment described by George Airy in his 1857 paper entitled “Account of pendulum experiments undertaken in the Harton colliery, for the purpose of determining the mean density of the Earth” produced an estimate of the mean density of the Earth that was 20% in error. Why was this?
After his failure to measure the mean density of the Earth in the Dolcoath mine in Cornwall in 1826, George Airy waited 30 years before making another attempt. For this he went to the Harton Pit near South Shields and used innovations such as electrical signalling. But was he any more successful?
The Republic of Croatia can lay claim to being the homeland of two scientists whose names are, if not exactly household words, have at least integrated themselves into the international vocabulary., but until April 2022, only one of them had a statue in Zagreb.
Between 1967 and 1913 aeromagnetic surveys were flown over eastern Papua New Guinea, but the results only became available during the country’s transition to full independence. Overlooked at the time, they now seem to have been largely forgotten
In early 1963 Australia’s Bureau of Mineral Resources, the BMR. carried out the first airborne proton magnetometer survey in the country, using the instrument designed and largely built by John Newman.
The availability of very detailed topographic grids has provided geologists of new ways of looking at areas. Sometimes the results can be spectacular.