Henry Cavendish (1731~ 1810) was an English physicist and chemist. He was born in Nice, France on October 10, 1731. One of Cavendish's major contributions was the completion of the torsion scale experiment for measuring gravitation in 1798, later known as the Cavendish experiment. He improved the torsion scale designed by the English mechanic John Michell (1724~ 1793), attached a small plane mirror to its suspension system, and used a telescope to manipulate and measure at a distance outdoors, preventing air disturbance (there was no vacuum equipment at that time). He hoisted a 6-foot wooden pole with a 39-inch silver-plated copper wire. A small shot ball with a diameter of 2 inches was fixed at each end of the rod, and two large shot balls with a diameter of 12 inches were used to attract them. The oscillation period caused by the attractive force between the shot balls was measured, and the attractive force of the two shot balls was calculated. From the calculated attractive force, the mass and density of the earth were calculated. He calculated that the density of the earth was 5.481 times the density of water (the modern value of the earth's density is 5.517g/cm3). From this, the value of the universal gravitational constant G can be calculated to be 6.754 × 10-11 Nm2/kg2 (the first four digits of the modern value are 6.672). The concept, design and operation of this experiment is very delicate, and the British physicist J.H. Poynting once commented on this experiment: "It ushered in a new era of weak force measurement."

Cavendish published "On Artificial Air" in 1766 and was awarded the Copley Medal of the Royal Society. He produced pure oxygen and determined the amount of oxygen and nitrogen in the air, proving that water was not an element but a compound. He was called "Newton in chemistry". Cavendish worked in his laboratory all his life and was known as "the richest scholar and the most learned millionaire". Cavendish died on February 24, 1810.