The Cavendish experiment is always interpreted now as a measurement of G, the universal gravitational constant, but that is an interpretation that Cavendish did not make. He thought that he had measured the mean density of the Earth, and he was only one of many experimenters measuring the density of the Earth by many methods during the 18th century.
Full
Published Online: 04 June 1998
Accepted: April 1986
The Cavendish experiment as Cavendish knew it
American Journal of Physics 55, 210 (1987);
https://doi.org/10.1119/1.15214