際際滷

際際滷Share a Scribd company logo

Henry cavendish english

Download as DOC, PDF
Riri Mardayeni
Riri Mardayeni

Henry Cavendish (1731-1810) was a highly distinguished British scientist regarded as the most eminent man of science of his day. He made several important scientific achievements, including demonstrating the existence of hydrogen, proving water is a compound, and determining the density of the Earth. Though he published little, after his death Clerk Maxwell found over 20 packages of Cavendish's manuscripts on electricity, which had quietly presaged many important results of the following century. Cavendish was an extremely shy man who lived as a recluse, yet participated in London's intellectual life as a fellow of the Royal Society and trustee of the British Museum.

1 of 4
Henry Cavendish (17311810) As a fellow-scientist wrote, Henry Cavendish possessed a clarity of comprehension and an acuteness of reasoning that have been the lot of very few of his predecessors since the days of Newton. At home and abroad he was regarded as the most distinguished British man of science of his day. Among his many achievements are the demonstration of the existence of hydrogen as a distinct substance, the demonstration that water is a compound and the determination of the density of the earth. He was also one of the pioneers of electrical research, presaging much of the work of Coulomb, Faraday and Ohm. Clerk Maxwell, who edited some of his papers, was fascinated by his character: Cavendish cared more for investigation than publication. He would undertake the most laborious researches in order to clear up a difficulty which no-one but himself could appreciate, or was even aware of. And we cannot doubt that the result of his enquiries, when successful, gave him a certain degree of satisfaction. But it did not excite in him that desire to communicate the discovery to others which, in the case of ordinary men of science, generally ensures the publication of their results. Lord Charles Cavendish, the third son of the second Duke of Devonshire, married Lady Anne Grey, the fourth daughter of Henry, Duke of Kent. She was living in Nice, owing to frail health, when her first child Henry was born on October 10, 1731. A second child, Frederick, was born in England two years later, but their mother died shortly afterwards. Little is known of the early years of the two boys, except that they attended the Hackney Academy, a London school well thought of in its day for the education of children of the upper classes in sound classical learning. Each of the brothers went up to the University of Cambridge, matriculated as a nobleman and resided there for four years, but left without taking a degree. The college to which they belonged was St Peters, commonly known as Peterhouse. Shortly after the younger brother had left Cambridge they made the customary tour on the continent; apart from Paris, it is not known where they went. Henry may well have studied mathematics and physics when he was in Paris. The brothers did not have much to do with each other later in life, although they remained on good terms. After returning to England, Henry Cavendish went to live with his father at a house in Great Marlborough Street, in the Soho district of London, and apparently continued to do so until his father died. It was during this period of almost thirty years that he carried out the fundamental electrical research which so impressed Clerk Maxwell. He began his research career by assisting his father, a gifted experimental physicist, who was a prominent fellow of the Royal Society. Lord Charles made some valuable investigations into heat, electricity and terrestrial magnetism. Franklin remarked that It were to be wished that this noble philosopher would communicate more of his experiments to the world, as he makes many, and with great accuracy. Lord Charles was not a wealthy man but the financial allowance he made to his eldest son was so small as to be described as niggardly by contemporaries. It is not known just where the money came from, but, in 1783,
when his father died, or even before, Henry Cavendish became extremely wealthy, apparently through a succession of legacies from relatives. However, by this time he had become accustomed to living parsimoniously. His large library of scientific works, housed in Bedford Square, was open to any serious scholars. At one time it was in a somewhat neglected state, so, having been told of a German scholar in straitened circumstances who was capable of classifying the books in a satisfactory manner, Cavendish arranged for him to act as his librarian; in return Cavendish gave him the princely sum of 贈10 000, with which to purchase an annuity. He could be remarkably generous when he felt so inclined. Cavendishs principal residence was a large villa at Clapham, then just a village south of London. Most of its rooms were equipped with scientific apparatus. It was at Clapham that he made his discovery of the composition of water and measured by means of a torsion balance the density of the earth. There was a ladder up a large tree in the garden, from the top of which he made astronomical and meteorological observations. He was very much a man of habit, invariably dining off leg of mutton and taking exactly the same walk every day on his own. His pathologically shy and nervous disposition, on which anyone who had any contact with Henry Cavendish was apt to remark, has been attributed to his comparative poverty during the first forty years of his life. In appearance Cavendish was tall and thin, his face intelligent and mild. His voice was hesitant and somewhat shrill. He retained the dress of his youth faded violet suit with high collar, frilled shirt-wrists and a knocker-tailed periwig. Each year on a fixed day his tailor provided him with a new suit that was a replica of the old one. When out-of-doors he was to be seen wearing a three-cornered hat. He would often be accompanied by Sir Charles Blagden, who for seven years acted as his assistant. As secretary of the Royal Society, Blagden made frequent visits to the continent, usually to Paris, where he was a friend of Berthollet and Laplace, amongst others, and courted the lively widow of Antoine Lavoisier. When eventually Cavendish parted with Blagdens services he provided him with an annuity of 贈500 and left him a legacy of 贈15 000 in his will. Cavendishs interests extended over a wide field of natural philosophy, and every subject of investigation was subjected to a rigorous quantitative examination. The results he obtained with simple methods and apparatus were amazing. He was not only a highly skilled experimentalist but also a capable mathematician. In common with others in England during this period, he employed the methods of Newton, for example the fluxional notation for differentiation. In chemistry he adhered to the old caloric theory of heat, although the experiments he performed were helping to undermine it. Like Newton, he had a deep dislike of controversy. As a result he published remarkably little; for example only two research papers on electricity, although, when Clerk Maxwell was editing Cavendishs electrical researches for publication, after his death, he found twenty packages full of manuscripts on mathematical and experimental electricity.
The vast bulk of the Cavendish papers must have given Maxwell pause, but, once he had begun, he found them fascinating. Cavendish had quietly presaged many of the important results of the following century. He had performed some extraordinarily accurate experiments with the crudest of equipment, using a pair of pithballs, on strings, which repelled each other to measure charge and his own body to measure resistance. In going through the papers Maxwell found many of the experiments mentioned so original that they seemed worth repeating, checking or improving. Cavendish had done his experiments by making himself part of the electric circuit and noticing how intense the electric shocks he felt under different circumstances were. To check his conclusions he would summon his servant Richard to replace him and then observe his servants reactions. Visitors to his laboratory were often pressed into taking part instead of Richard; Cavendish offended a visiting American physicist, who refused to act as a guinea pig and went off saying when an English man of science comes to the United States we do not treat him like that. Although Franklins work had been published twenty years earlier, Cavendishs paper An attempt to explain some of the principal phenomena of electricity by means of an elastic fluid involves basically the same idea, but gives it a mathematical treatment, quantitative rather than qualitative. Both Cavendish and Franklin served on a committee of the Royal Society to report on the best way of protecting buildings from lightning; they recommended the installation of pointed conductors. However, others were in favour of blunt ends, and George III agreed.Anotorious controversy erupted, with political overtones, since pointed ends were thought somehow to be unpatriotic. Although Cavendish mainly lived as a recluse owing to a morbid dislike of society, he nevertheless participated in the intellectual life of London. He was a member of the Royal Society of Arts, a trustee of the British Museum, a fellow of the Society of Antiquaries, a manager of the Royal Institution and a foreign associate of the Paris Academy. Like his father, he was prominent in the Royal Society, to which he was elected in 1760, served on the Council and some of its committees; and regularly attended the Dining Club, to which he often brought guests. They were advised that it was useless to try to engage him in conversation on any non-scientific topic. The only known portrait of him, now in the British Museum, was drawn surreptitiously at one of the club dinners. Henry, later Lord, Brougham recalled seeing him at a Royal Society Conversazione and hearing the shrill cry he uttered as he shuffled quickly from room to room, seeming to be annoyed if looked at, but sometimes approaching to hear what was passing among others. His walk was quick and uneasy. He probably uttered fewer words in the course of his life than any man who lived to fourscore years, not at all excepting the monks of La Trappe. Of the many stories told about his idiosyncrasies, one concerns a distinguished foreign scientist who said that he wished to meet one of the greatest intellectual ornaments of this country, and one of the most profound
philosophers of all time. Cavendish was so embarrassed that he was reduced to total silence and escaped in his carriage at the first opportunity. Cavendish made a number of journeys by carriage within Britain, always in the summer, when conditions of travel were least difficult, and generally accompanied by Blagden. Although usually their main purpose was to visit other men of science, generally some scientific work was done en route; for example they studied the variation of barometric pressure with altitude, or collected specimens of minerals to be examined at leisure on their return. They inspected many of the places where science was being applied in industry, as the industrial revolution began to gather momentum. Often the people he met were later guests of his at the Royal Society Dining Club. Cavendish died on February 24, 1810, at the age of seventy-eight, and was buried in All Saints Church, Derby, now designated the cathedral, where his famous ancestor Bess of Hardwick had built an elaborate tomb for herself. Owing to his frugal life-style, he had accumulated a fortune of over a million pounds, a huge sum in those days; he was one of the richest men in England. When he died none of this wealth went directly to support scientific research; he believed that it should return to the family from which it came. However, many years later the University of Cambridge benefited from the generosity of the Cavendish family through the endowment of the Cavendish Professorship of Experimental Physics and the Cavendish Laboratory. Charles Augustin Coulomb (17361806) The end of the Thirty Years War left France the most powerful nation in Europe. Although the golden age of French science was yet to come, some remarkable physicists were already distinguishing themselves before the end of the ancien r 卒egime. One of the first was Coulomb, the subject of our next profile. He has been described as the complete physicist, rivalled in the eighteenth century only by Henry Cavendish, combining experimental skill, accuracy of measurement and great originality with mathematical powers adequate to all his demands. He invented the torsion balance and used it to show that the force between electrically charged particles is proportional to the product of their charges and inversely proportional to the distance between them. This fundamental result is known as Coulombs law; the unit of electrical charge is also named after him.

More Related Content

Henry cavendish english

  • 1. Henry Cavendish (17311810) As a fellow-scientist wrote, Henry Cavendish possessed a clarity of comprehension and an acuteness of reasoning that have been the lot of very few of his predecessors since the days of Newton. At home and abroad he was regarded as the most distinguished British man of science of his day. Among his many achievements are the demonstration of the existence of hydrogen as a distinct substance, the demonstration that water is a compound and the determination of the density of the earth. He was also one of the pioneers of electrical research, presaging much of the work of Coulomb, Faraday and Ohm. Clerk Maxwell, who edited some of his papers, was fascinated by his character: Cavendish cared more for investigation than publication. He would undertake the most laborious researches in order to clear up a difficulty which no-one but himself could appreciate, or was even aware of. And we cannot doubt that the result of his enquiries, when successful, gave him a certain degree of satisfaction. But it did not excite in him that desire to communicate the discovery to others which, in the case of ordinary men of science, generally ensures the publication of their results. Lord Charles Cavendish, the third son of the second Duke of Devonshire, married Lady Anne Grey, the fourth daughter of Henry, Duke of Kent. She was living in Nice, owing to frail health, when her first child Henry was born on October 10, 1731. A second child, Frederick, was born in England two years later, but their mother died shortly afterwards. Little is known of the early years of the two boys, except that they attended the Hackney Academy, a London school well thought of in its day for the education of children of the upper classes in sound classical learning. Each of the brothers went up to the University of Cambridge, matriculated as a nobleman and resided there for four years, but left without taking a degree. The college to which they belonged was St Peters, commonly known as Peterhouse. Shortly after the younger brother had left Cambridge they made the customary tour on the continent; apart from Paris, it is not known where they went. Henry may well have studied mathematics and physics when he was in Paris. The brothers did not have much to do with each other later in life, although they remained on good terms. After returning to England, Henry Cavendish went to live with his father at a house in Great Marlborough Street, in the Soho district of London, and apparently continued to do so until his father died. It was during this period of almost thirty years that he carried out the fundamental electrical research which so impressed Clerk Maxwell. He began his research career by assisting his father, a gifted experimental physicist, who was a prominent fellow of the Royal Society. Lord Charles made some valuable investigations into heat, electricity and terrestrial magnetism. Franklin remarked that It were to be wished that this noble philosopher would communicate more of his experiments to the world, as he makes many, and with great accuracy. Lord Charles was not a wealthy man but the financial allowance he made to his eldest son was so small as to be described as niggardly by contemporaries. It is not known just where the money came from, but, in 1783,
  • 2. when his father died, or even before, Henry Cavendish became extremely wealthy, apparently through a succession of legacies from relatives. However, by this time he had become accustomed to living parsimoniously. His large library of scientific works, housed in Bedford Square, was open to any serious scholars. At one time it was in a somewhat neglected state, so, having been told of a German scholar in straitened circumstances who was capable of classifying the books in a satisfactory manner, Cavendish arranged for him to act as his librarian; in return Cavendish gave him the princely sum of 贈10 000, with which to purchase an annuity. He could be remarkably generous when he felt so inclined. Cavendishs principal residence was a large villa at Clapham, then just a village south of London. Most of its rooms were equipped with scientific apparatus. It was at Clapham that he made his discovery of the composition of water and measured by means of a torsion balance the density of the earth. There was a ladder up a large tree in the garden, from the top of which he made astronomical and meteorological observations. He was very much a man of habit, invariably dining off leg of mutton and taking exactly the same walk every day on his own. His pathologically shy and nervous disposition, on which anyone who had any contact with Henry Cavendish was apt to remark, has been attributed to his comparative poverty during the first forty years of his life. In appearance Cavendish was tall and thin, his face intelligent and mild. His voice was hesitant and somewhat shrill. He retained the dress of his youth faded violet suit with high collar, frilled shirt-wrists and a knocker-tailed periwig. Each year on a fixed day his tailor provided him with a new suit that was a replica of the old one. When out-of-doors he was to be seen wearing a three-cornered hat. He would often be accompanied by Sir Charles Blagden, who for seven years acted as his assistant. As secretary of the Royal Society, Blagden made frequent visits to the continent, usually to Paris, where he was a friend of Berthollet and Laplace, amongst others, and courted the lively widow of Antoine Lavoisier. When eventually Cavendish parted with Blagdens services he provided him with an annuity of 贈500 and left him a legacy of 贈15 000 in his will. Cavendishs interests extended over a wide field of natural philosophy, and every subject of investigation was subjected to a rigorous quantitative examination. The results he obtained with simple methods and apparatus were amazing. He was not only a highly skilled experimentalist but also a capable mathematician. In common with others in England during this period, he employed the methods of Newton, for example the fluxional notation for differentiation. In chemistry he adhered to the old caloric theory of heat, although the experiments he performed were helping to undermine it. Like Newton, he had a deep dislike of controversy. As a result he published remarkably little; for example only two research papers on electricity, although, when Clerk Maxwell was editing Cavendishs electrical researches for publication, after his death, he found twenty packages full of manuscripts on mathematical and experimental electricity.
  • 3. The vast bulk of the Cavendish papers must have given Maxwell pause, but, once he had begun, he found them fascinating. Cavendish had quietly presaged many of the important results of the following century. He had performed some extraordinarily accurate experiments with the crudest of equipment, using a pair of pithballs, on strings, which repelled each other to measure charge and his own body to measure resistance. In going through the papers Maxwell found many of the experiments mentioned so original that they seemed worth repeating, checking or improving. Cavendish had done his experiments by making himself part of the electric circuit and noticing how intense the electric shocks he felt under different circumstances were. To check his conclusions he would summon his servant Richard to replace him and then observe his servants reactions. Visitors to his laboratory were often pressed into taking part instead of Richard; Cavendish offended a visiting American physicist, who refused to act as a guinea pig and went off saying when an English man of science comes to the United States we do not treat him like that. Although Franklins work had been published twenty years earlier, Cavendishs paper An attempt to explain some of the principal phenomena of electricity by means of an elastic fluid involves basically the same idea, but gives it a mathematical treatment, quantitative rather than qualitative. Both Cavendish and Franklin served on a committee of the Royal Society to report on the best way of protecting buildings from lightning; they recommended the installation of pointed conductors. However, others were in favour of blunt ends, and George III agreed.Anotorious controversy erupted, with political overtones, since pointed ends were thought somehow to be unpatriotic. Although Cavendish mainly lived as a recluse owing to a morbid dislike of society, he nevertheless participated in the intellectual life of London. He was a member of the Royal Society of Arts, a trustee of the British Museum, a fellow of the Society of Antiquaries, a manager of the Royal Institution and a foreign associate of the Paris Academy. Like his father, he was prominent in the Royal Society, to which he was elected in 1760, served on the Council and some of its committees; and regularly attended the Dining Club, to which he often brought guests. They were advised that it was useless to try to engage him in conversation on any non-scientific topic. The only known portrait of him, now in the British Museum, was drawn surreptitiously at one of the club dinners. Henry, later Lord, Brougham recalled seeing him at a Royal Society Conversazione and hearing the shrill cry he uttered as he shuffled quickly from room to room, seeming to be annoyed if looked at, but sometimes approaching to hear what was passing among others. His walk was quick and uneasy. He probably uttered fewer words in the course of his life than any man who lived to fourscore years, not at all excepting the monks of La Trappe. Of the many stories told about his idiosyncrasies, one concerns a distinguished foreign scientist who said that he wished to meet one of the greatest intellectual ornaments of this country, and one of the most profound
  • 4. philosophers of all time. Cavendish was so embarrassed that he was reduced to total silence and escaped in his carriage at the first opportunity. Cavendish made a number of journeys by carriage within Britain, always in the summer, when conditions of travel were least difficult, and generally accompanied by Blagden. Although usually their main purpose was to visit other men of science, generally some scientific work was done en route; for example they studied the variation of barometric pressure with altitude, or collected specimens of minerals to be examined at leisure on their return. They inspected many of the places where science was being applied in industry, as the industrial revolution began to gather momentum. Often the people he met were later guests of his at the Royal Society Dining Club. Cavendish died on February 24, 1810, at the age of seventy-eight, and was buried in All Saints Church, Derby, now designated the cathedral, where his famous ancestor Bess of Hardwick had built an elaborate tomb for herself. Owing to his frugal life-style, he had accumulated a fortune of over a million pounds, a huge sum in those days; he was one of the richest men in England. When he died none of this wealth went directly to support scientific research; he believed that it should return to the family from which it came. However, many years later the University of Cambridge benefited from the generosity of the Cavendish family through the endowment of the Cavendish Professorship of Experimental Physics and the Cavendish Laboratory. Charles Augustin Coulomb (17361806) The end of the Thirty Years War left France the most powerful nation in Europe. Although the golden age of French science was yet to come, some remarkable physicists were already distinguishing themselves before the end of the ancien r 卒egime. One of the first was Coulomb, the subject of our next profile. He has been described as the complete physicist, rivalled in the eighteenth century only by Henry Cavendish, combining experimental skill, accuracy of measurement and great originality with mathematical powers adequate to all his demands. He invented the torsion balance and used it to show that the force between electrically charged particles is proportional to the product of their charges and inversely proportional to the distance between them. This fundamental result is known as Coulombs law; the unit of electrical charge is also named after him.