When did Henry Cavendish report the measurement of the gravitational constant with the mass and density of the Earth?  

The correct answer is June 1798.

 Key Points

• Henry Cavendish:-
  • He was a brilliant scientist who made significant contributions to chemistry and physics.
  • He discovered hydrogen in 1766 and measured the gravitational constant in 1798.
  • His work on the gravitational constant was particularly important, as it provided the first accurate measurement of the force of gravity between masses in the laboratory.
  • He reported the measurement of the gravitational constant with the mass and density of the Earth in June 1798. His results were published in a 57-page paper in the Transactions of the Royal Society entitled “Experiments to Determine the Density of the Earth.” 
  • Cavendish's experiment was the first to measure the force of gravity between masses in the laboratory and the first to yield accurate values for the gravitational constant. He used a torsion balance to measure the tiny gravitational attraction between two small lead balls and two much larger stationary lead balls.
  • Cavendish's results were surprisingly accurate, and they remained the best available measurement of the gravitational constant for over a century. His experiment is considered to be one of the most important and influential experiments in the history of physics.