-
1 Davy, Sir Humphry
[br]b. 17 December 1778 Penzance, Cornwall, Englandd. 29 May 1829 Geneva, Switzerland[br]English chemist, discoverer of the alkali and alkaline earth metals and the halogens, inventor of the miner's safety lamp.[br]Educated at the Latin School at Penzance and from 1792 at Truro Grammar School, Davy was apprenticed to a surgeon in Penzance. In 1797 he began to teach himself chemistry by reading, among other works, Lavoisier's elementary treatise on chemistry. In 1798 Dr Thomas Beddoes of Bristol engaged him as assistant in setting up his Pneumatic Institution to pioneer the medical application of the newly discovered gases, especially oxygen.In 1799 he discovered the anaesthetic properties of nitrous oxide, discovered not long before by the chemist Joseph Priestley. He also noted its intoxicating qualities, on account of which it was dubbed "laughing-gas". Two years later Count Rumford, founder of the Royal Institution in 1800, appointed Davy Assistant Lecturer, and the following year Professor. His lecturing ability soon began to attract large audiences, making science both popular and fashionable.Davy was stimulated by Volta's invention of the voltaic pile, or electric battery, to construct one for himself in 1800. That enabled him to embark on the researches into electrochemistry by which is chiefly known. In 1807 he tried decomposing caustic soda and caustic potash, hitherto regarded as elements, by electrolysis and obtained the metals sodium and potassium. He went on to discover the metals barium, strontium, calcium and magnesium by the same means. Next, he turned his attention to chlorine, which was then regarded as an oxide in accordance with Lavoisier's theory that oxygen was the essential component of acids; Davy failed to decompose it, however, even with the aid of electricity and concluded that it was an element, thus disproving Lavoisier's view of the nature of acids. In 1812 Davy published his Elements of Chemical Philosophy, in which he presented his chemical ideas without, however, committing himself to the atomic theory, recently advanced by John Dalton.In 1813 Davy engaged Faraday as Assistant, perhaps his greatest service to science. In April 1815 Davy was asked to assist in the development of a miner's lamp which could be safely used in a firedamp (methane) laden atmosphere. The "Davy lamp", which emerged in January 1816, had its flame completely surrounded by a fine wire mesh; George Stephenson's lamp, based on a similar principle, had been introduced into the Northumberland pits several months earlier, and a bitter controversy as to priority of invention ensued, but it was Davy who was awarded the prize for inventing a successful safety lamp.In 1824 Davy was the first to suggest the possibility of conferring cathodic protection to the copper bottoms of naval vessels by the use of sacrificial electrodes. Zinc and iron were found to be equally effective in inhibiting corrosion, although the scheme was later abandoned when it was found that ships protected in this way were rapidly fouled by weeds and barnacles.[br]Principal Honours and DistinctionsKnighted 1812. FRS 1803; President, Royal Society 1820. Royal Society Copley Medal 1805.Bibliography1812, Elements of Chemical Philosophy.1839–40, The Collected Works of Sir Humphry Davy, 9 vols, ed. John Davy, London.Further ReadingJ.Davy, 1836, Memoirs of the Life of Sir Humphry Davy, London (a classic biography). J.A.Paris, 1831, The Life of Sir Humphry Davy, London (a classic biography). H.Hartley, 1967, Humphry Davy, London (a more recent biography).J.Z.Fullmer, 1969, Cambridge, Mass, (a bibliography of Davy's works).ASD -
2 Wilde, Henry
SUBJECT AREA: Electricity[br]b. 1833 Manchester, Englandd. 28 March 1919 Alderley Edge, Cheshire, England[br]English inventor and pioneer manufacturer of electrical generators.[br]After completing a mechanical engineering apprenticeship Wilde commenced in business as a telegraph and lightning conductor specialist in Lancashire. Several years spent on the design of an alphabetic telegraph resulted in a number of patents. In 1864 he secured a patent for an electromagnetic generator which gave alternating current from a shuttle-wound armature, the field being excited by a small direct-current magneto. Wilde's invention was described to the Royal Society by Faraday in March 1866. When demonstrated at the Paris Exhibition of 1867, Wilde's machine produced sufficient power to maintain an arc light. The small size of the generator provided a contrast to the large and heavy magnetoelectric machines also exhibited. He discovered, by experiment, that alternators in synchronism could be connected in parallel. At about the same time John Hopkinson arrived at the same conclusions on theoretical grounds.Between 1866 and 1877 he sold ninety-four machines with commutators for electroplating purposes, a number being purchased by Elkingtons of Birmingham. He also supplied generators for the first use of electric searchlights on battleships. In his early experiments Wilde was extremely close to the discovery of true self-excitation from remnant magnetism, a principle which he was to discover in 1867 on machines intended for electroplating. His patents proved to be financially successful and he retired from business in 1884. During the remaining thirty-five years of his life he published many scientific papers, turning from experimental work to philosophical and, finally, theological matters. His record as an inventor established him as a pioneer of electrical engineering, but his lack of scientific training was to restrict his later contributions.[br]Principal Honours and DistinctionsFRS 1886.Bibliography1 December 1863, British patent no. 3,006 (alternator with a magneto-exciter).1866, Proceedings of the Royal Society 14:107–11 (first report on Wilde's experiments). 1900, autobiographical note, Journal of the Institution of Electrical Engineers 29:3–17.Further ReadingW.W.Haldane Gee. 1920, biography, Memoirs, Manchester Literary and Philosophical Society 63:1–16 (a comprehensive account).P.Dunsheath, 1962, A History of Electrical Engineering, London: Faber \& Faber, pp. 110–12 (a short account).GW
См. также в других словарях:
discover — discoverable, adj. discoverably, adv. /di skuv euhr/, v.t. 1. to see, get knowledge of, learn of, find, or find out; gain sight or knowledge of (something previously unseen or unknown): to discover America; to discover electricity. 2. to notice… … Universalium
Electricity meter — Typical North American domestic analog electricity meter … Wikipedia
Hydro-Québec's electricity transmission system — is an expansive, international power transmission system located in Quebec, Canada with extensions into the Northeastern United States. Major expansion of the network began with the commissioning of the alternating current 735,000 volt (735 kV)… … Wikipedia
The History and Present State of Electricity — (1767), by eighteenth century British polymath Joseph Priestley, is a survey of the study of electricity up until 1766 as well as a description of experiments by Priestley himself. [Priestley, Joseph. The History and Present State of Electricity … Wikipedia
Kids Discover — Infobox Magazine title = Kids Discover image size = image caption = editor = editor title = previous editor = staff writer = frequency = Monthly circulation = 350,000cite web |url=http://www.schoollibraryjournal.com/article/CA6438277.html |title … Wikipedia
The History and Present State of Electricity — Page de titre de la troisième édition de The History and Present State of Electricity. The History and Present State of Electricity (traduction française : Histoire de l électricité par Mathurin Jacques Brisson[1]), publié … Wikipédia en Français
Hydro-Québec — Type Government owned corporation Industry Electric Utilities Founded … Wikipedia
History of Physics — History of Physics † Catholic Encyclopedia ► History of Physics The subject will be treated under the following heads: I. A Glance at Ancient Physics; II. Science and Early Christian Scholars; III. A Glance at Arabian Physics; IV.… … Catholic encyclopedia
science, history of — Introduction the history of science from its beginnings in prehistoric times to the 20th century. On the simplest level, science is knowledge of the world of nature. There are many regularities in nature that mankind has had to… … Universalium
Ireland — This article is about the island. For the sovereign state of the same name, see Republic of Ireland. For the constituent country of the United Kingdom, see Northern Ireland. For other uses, see Ireland (disambiguation). Coordinates … Wikipedia
electromagnetism — /i lek troh mag ni tiz euhm/, n. 1. the phenomena associated with electric and magnetic fields and their interactions with each other and with electric charges and currents. 2. Also, electromagnetics. the science that deals with these phenomena.… … Universalium
