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.

In December 2021, someone from the South Australia Department of Mines and Energy posted a historical note on LinkedIn., with pictures of survey aircraft VH-BUR. It brought vividly to mind the sight, and odour, of her companion, VH-MIN

A paper published in 2014 shows two possible locations for the Owen Stanley Fault Zone in eastern Papua, one based on gravity, the other on geology. Which is right?

In mid-October 2021 an image of the geoid based on data from NASA’s GRACE satellite was posted on LinkedIn. It was an object lesson in the perils of attempting to disseminate science via a platform that restricts posts to 2500 characters and comments to 1250 characters.

One milligal is approximately one millionth of the Earth’s gravity field, so it would seem that the periods of pendulums used for measuring gravity would have to be measured to a few millionths of a second for the results to be useful. This was simply not possible in the early nineteenth century, but pendulums were being used then to obtain results accurate to a few tens of milligal. How was it done?

Between April 1791 and January 1794, officers of Alejandro Malaspina’s mission to the Pacific measured gravity at no fewer than 17 different locations. It was the first truly global gravity survey, but how accurate was it?