The famed Henry Cavendish, the scientist who performed the first experiment which allowed the mass of the planet Earth to be calculated. Scientist Henry Cavendish was of exceptionally wealthy and noble birth. Namely, his grandfather was William Cavendish, the Duke of Devonshire and one of the highest-ranking British aristocrats. The Cavendish family was very influential in England since the Middle Ages, and in the 16th century it became one of the wealthiest and politically most important families in the whole of Britain. They received two ducal titles (Devonshire and Newcastle).
Indeed, the dukes of Devonshire were, along with the marquesses of Salisbury and the earls of Derby, politically the most influential aristocrats in Britain. One of the most well-known members of that family was Georgina Cavendish, Duchess of Devonshire. A movie was made about her in 2008, starring Keira Knightley.
The scientist Henry Cavendish, born on this day in 1731, invested his huge inherited wealth into scientific research. He discovered the chemical element Hydrogen (H) and called it “flammable air”. He calculated the Earth’s mass with the help of a special instrument which contained two large lead balls and two smaller ones. By using Newton’s Law of Gravity and by knowing the torsion of the wire from which the balls were suspended, one could measure the gravitational constant, and thus the mass of Earth. Henry Cavendish died in 1810 as one of the wealthiest people in Britain, despite the large amount of money he had invested in his scientific experiments.