1731 Henry Cavendish was born on 10 October, in Niece, France, four years later after Newton’s death. He was one of the greatest scientists of England that contributed to rigorous scientific contribution of Physics and Chemistry. His father, Lord Charles Cavendish, Duke of Dovonshire, was a philosopher who was concerned of scientific research field.
1733 This year, his mother, Ane Grey, fourth daughter of Henry Grey, Duke of Kent, has died, just three months after giving birth to her second son, Frederick. Henry was only two years and remained in the care of his father.
1742 At age 11, Henry follows Hackney Academy, a private school in London.
1748 This year, he entered the University of Cambridge, at St. Peter's College, now known as Peterhouse, but gave up three years later on 23 February 1751, without ever taking a diploma, returning to his father in London. Even if he was a member of an aristocratic family, Henry Cavendish had only a small part of his parents’ fortune during youth. Yet, he refused all public positions that he could have because of his origin, in order to have time for his scientific researches. It is told that at Royal Society club dinners, Cavendish had in the pocket only five shillings to pay the dish and not more. It happened that one of his uncles, who had made a big fortune in Indies (discontent because the family had neglected his grandson who had remarkable skills), left him his entire riches. So, Cavendish became the richest scientist. This fact did not change his habits and the simplicity of life. He established a big library and a Cabinet of Physics equipped with all existing devices at that time. Both library and cabinet were available for those who wanted this. It is said that he did reserve any benefits for him and he borrowed his own books fulfilling the same formalities as the other people. He sustained and supported many young people that were interested in studying and research. One day, the man charged with inventory preserving and guarding of the Cabinet told him that a young man had broken one of those expensive devices. Cavendish answered: “Young people must break devices to learn how to use them; take action to manufacture another one”.
1762 Benjamin Franklin, in a letter send on this year, appreciate his father's research on heated glass conductivity.
Cavendish hardly contributed to Chemistry field, being one of founders of “defined proportions” law and of hydrogen and argon discoveries. Cavendish demonstrated that water is formed by hydrogen’s burn. Regarding Physics he concluded by experience that different gases have approximately the same expansion coefficient. Cavendish was due to the notion of “the capacity of a conductor” and the results of done experiments by him regarding electricity represent an anticipation of almost half a century of Ohm’s law.
But, his most famous experience is that by which he “determined Earth’s density”. The idea was not his, it was Mitchell’s, like the device he used; Mitchell died without using the device.
Cavendish perfected the device making it stronger and more precisely; he considered that Earths’ average density compared to water is 5.48. Nowadays, the approximate value is 5.52 due to the fact that gravity acceleration is 9.81/s2.
Cavendish was also interested in other Physics issues: energy, stimulus, thermometry, heat’s nature, but what must be admired is the rigorous accuracy he wanted to do each experience, accuracy that led him to discoveries that had not been noticed by great scientists like Scheele and Priestley. It can be said that he started a new age of science, period from quantitative experiences to qualitative ones because his assumptions are based on measurements and not uncontrolled admitted.
Nowadays Cavendish can be an example regarding the way to work and passion for scientific research.
1810 On 24 February, Henry Cavendish, passed away in London, England.[1]
Bibliography:
