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101 altimeter
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102 amplifier
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103 analyzer
анализатор; специалист по анализу; испытательное устройство; тестер; дефектоскоп -
104 Bain, Alexander
[br]b. October 1810 Watten, Scotlandd. 2 January 1877 Kirkintilloch, Scotland[br]Scottish inventor and entrepreneur who laid the foundations of electrical horology and designed an electromagnetic means of transmitting images (facsimile).[br]Alexander Bain was born into a crofting family in a remote part of Scotland. He was apprenticed to a watchmaker in Wick and during that time he was strongly influenced by a lecture on "Heat, sound and electricity" that he heard in nearby Thurso. This lecture induced him to take up a position in Clerkenwell in London, working as a journeyman clockmaker, where he was able to further his knowledge of electricity by attending lectures at the Adelaide Gallery and the Polytechnic Institution. His thoughts naturally turned to the application of electricity to clockmaking, and despite a bitter dispute with Charles Wheatstone over priority he was granted the first British patent for an electric clock. This patent, taken out on 11 January 1841, described a mechanism for an electric clock, in which an oscillating component of the clock operated a mechanical switch that initiated an electromagnetic pulse to maintain the regular, periodic motion. This principle was used in his master clock, produced in 1845. On 12 December of the same year, he patented a means of using electricity to control the operation of steam railway engines via a steam-valve. His earliest patent was particularly far-sighted and anticipated most of the developments in electrical horology that occurred during the nineteenth century. He proposed the use of electricity not only to drive clocks but also to distribute time over a distance by correcting the hands of mechanical clocks, synchronizing pendulums and using slave dials (here he was anticipated by Steinheil). However, he was less successful in putting these ideas into practice, and his electric clocks proved to be unreliable. Early electric clocks had two weaknesses: the battery; and the switching mechanism that fed the current to the electromagnets. Bain's earth battery, patented in 1843, overcame the first defect by providing a reasonably constant current to drive his clocks, but unlike Hipp he failed to produce a reliable switch.The application of Bain's numerous patents for electric telegraphy was more successful, and he derived most of his income from these. They included a patent of 12 December 1843 for a form of fax machine, a chemical telegraph that could be used for the transmission of text and of images (facsimile). At the receiver, signals were passed through a moving band of paper impregnated with a solution of ammonium nitrate and potassium ferrocyanide. For text, Morse code signals were used, and because the system could respond to signals faster than those generated by hand, perforated paper tape was used to transmit the messages; in a trial between Paris and Lille, 282 words were transmitted in less than one minute. In 1865 the Abbé Caselli, a French engineer, introduced a commercial fax service between Paris and Lyons, based on Bain's device. Bain also used the idea of perforated tape to operate musical wind instruments automatically. Bain squandered a great deal of money on litigation, initially with Wheatstone and then with Morse in the USA. Although his inventions were acknowledged, Bain appears to have received no honours, but when towards the end of his life he fell upon hard times, influential persons in 1873 secured for him a Civil List Pension of £80 per annum and the Royal Society gave him £150.[br]Bibliography1841, British patent no. 8,783; 1843, British patent no. 9,745; 1845, British patent no.10,838; 1847, British patent no. 11,584; 1852, British patent no. 14,146 (all for electric clocks).1852, A Short History of the Electric Clocks with Explanation of Their Principles andMechanism and Instruction for Their Management and Regulation, London; reprinted 1973, introd. W.Hackmann, London: Turner \& Devereux (as the title implies, this pamphlet was probably intended for the purchasers of his clocks).Further ReadingThe best account of Bain's life and work is in papers by C.A.Aked in Antiquarian Horology: "Electricity, magnetism and clocks" (1971) 7: 398–415; "Alexander Bain, the father of electrical horology" (1974) 9:51–63; "An early electric turret clock" (1975) 7:428–42. These papers were reprinted together (1976) in A Conspectus of Electrical Timekeeping, Monograph No. 12, Antiquarian Horological Society: Tilehurst.J.Finlaison, 1834, An Account of Some Remarkable Applications of the Electric Fluid to the Useful Arts by Alexander Bain, London (a contemporary account between Wheatstone and Bain over the invention of the electric clock).J.Munro, 1891, Heroes of the Telegraph, Religious Tract Society.J.Malster \& M.J.Bowden, 1976, "Facsimile. A Review", Radio \&Electronic Engineer 46:55.D.J.Weaver, 1982, Electrical Clocks and Watches, Newnes.T.Hunkin, 1993, "Just give me the fax", New Scientist (13 February):33–7 (provides details of Bain's and later fax devices).See also: Bakewell, Frederick C.DV / KF -
105 Galilei, Galileo
SUBJECT AREA: Photography, film and optics[br]b. 15 February 1564 Pisa, Italyd. 8 January 1642 Arcetri, near Florence, Italy[br]Italian mathematician, astronomer and physicist who established the principle of the pendulum and was first to exploit the telescope.[br]Galileo began studying medicine at the University of Pisa but soon turned to his real interests, mathematics, mechanics and astronomy. He became Professor of Mathematics at Pisa at the age of 25 and three years later moved to Padua. In 1610 he transferred to Florence. While still a student he discovered the isochronous property of the pendulum, probably by timing with his pulse the swings of a hanging lamp during a religious ceremony in Pisa Cathedral. He later designed a pendulum-controlled clock, but it was not constructed until after his death, and then not successfully; the first successful pendulum clock was made by the Dutch scientist Christiaan Huygens in 1656. Around 1590 Galileo established the laws of motion of falling bodies, by timing rolling balls down inclined planes and not, as was once widely believed, by dropping different weights from the Leaning Tower of Pisa. These and other observations received definitive treatment in his Discorsi e dimostrazioni matematiche intorno a due nuove scienzi attenenti alla, meccanica (Dialogues Concerning Two New Sciences…) which was completed in 1634 and first printed in 1638. This work also included Galileo's proof that the path of a projectile was a parabola and, most importantly, the development of the concept of inertia.In astronomy Galileo adopted the Copernican heliocentric theory of the universe while still in his twenties, but he lacked the evidence to promote it publicly. That evidence came with the invention of the telescope by the Dutch brothers Lippershey. Galileo heard of its invention in 1609 and had his own instrument constructed, with a convex object lens and concave eyepiece, a form which came to be known as the Galilean telescope. Galileo was the first to exploit the telescope successfully with a series of striking astronomical discoveries. He was also the first to publish the results of observations with the telescope, in his Sidereus nuncius (Starry Messenger) of 1610. All the discoveries told against the traditional view of the universe inherited from the ancient Greeks, and one in particular, that of the four satellites in orbit around Jupiter, supported the Copernican theory in that it showed that there could be another centre of motion in the universe besides the Earth: if Jupiter, why not the Sun? Galileo now felt confident enough to advocate the theory, but the advance of new ideas was opposed, not for the first or last time, by established opinion, personified in Galileo's time by the ecclesiastical authorities in Rome. Eventually he was forced to renounce the Copernican theory, at least in public, and turn to less contentious subjects such as the "two new sciences" of his last and most important work.[br]Bibliography1610, Sidereus nuncius (Starry Messenger); translation by A.Van Helden, 1989, Sidereus Nuncius, or the Sidereal Messenger; Chicago: University of Chicago Press.1623, Il Saggiatore (The Assayer).1632, Dialogo sopre i due massimi sistemi del mondo, tolemaico e copernicano (Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican); translation, 1967, Berkeley: University of California Press.1638, Discorsi e dimostrazioni matematiche intorno a due nuove scienzi attenenti allameccanica (Dialogues Concerning Two New Sciences…); translation, 1991, Buffalo, New York: Prometheus Books (reprint).Further ReadingG.de Santillana, 1955, The Crime of Galileo, Chicago: University of Chicago Press; also 1958, London: Heinemann.H.Stillman Drake, 1980, Galileo, Oxford: Oxford Paperbacks. M.Sharratt, 1994, Galileo: Decisive Innovator, Oxford: Blackwell.J.Reston, 1994, Galileo: A Life, New York: HarperCollins; also 1994, London: Cassell.A.Fantoli, 1994, Galileo: For Copemicanism and for the Church, trans. G.V.Coyne, South Bend, Indiana: University of Notre Dame Press.LRD -
106 Huygens, Christiaan
SUBJECT AREA: Horology[br]b. 14 April 1629 The Hague, the Netherlandsd. 8 June 1695 The Hague, the Netherlands[br]Dutch scientist who was responsible for two of the greatest advances in horology: the successful application of both the pendulum to the clock and the balance spring to the watch.[br]Huygens was born into a cultured and privileged class. His father, Constantijn, was a poet and statesman who had wide interests. Constantijn exerted a strong influence on his son, who was educated at home until he reached the age of 16. Christiaan studied law and mathematics at Ley den University from 1645 to 1647, and continued his studies at the Collegium Arausiacum in Breda until 1649. He then lived at The Hague, where he had the means to devote his time entirely to study. In 1666 he became a Member of the Académie des Sciences in Paris and settled there until his return to The Hague in 1681. He also had a close relationship with the Royal Society and visited London on three occasions, meeting Newton on his last visit in 1689. Huygens had a wide range of interests and made significant contributions in mathematics, astronomy, optics and mechanics. He also made technical advances in optical instruments and horology.Despite the efforts of Burgi there had been no significant improvement in the performance of ordinary clocks and watches from their inception to Huygens's time, as they were controlled by foliots or balances which had no natural period of oscillation. The pendulum appeared to offer a means of improvement as it had a natural period of oscillation that was almost independent of amplitude. Galileo Galilei had already pioneered the use of a freely suspended pendulum for timing events, but it was by no means obvious how it could be kept swinging and used to control a clock. Towards the end of his life Galileo described such a. mechanism to his son Vincenzio, who constructed a model after his father's death, although it was not completed when he himself died in 1642. This model appears to have been copied in Italy, but it had little influence on horology, partly because of the circumstances in which it was produced and possibly also because it differed radically from clocks of that period. The crucial event occurred on Christmas Day 1656 when Huygens, quite independently, succeeded in adapting an existing spring-driven table clock so that it was not only controlled by a pendulum but also kept it swinging. In the following year he was granted a privilege or patent for this clock, and several were made by the clockmaker Salomon Coster of The Hague. The use of the pendulum produced a dramatic improvement in timekeeping, reducing the daily error from minutes to seconds, but Huygens was aware that the pendulum was not truly isochronous. This error was magnified by the use of the existing verge escapement, which made the pendulum swing through a large arc. He overcame this defect very elegantly by fitting cheeks at the pendulum suspension point, progressively reducing the effective length of the pendulum as the amplitude increased. Initially the cheeks were shaped empirically, but he was later able to show that they should have a cycloidal shape. The cheeks were not adopted universally because they introduced other defects, and the problem was eventually solved more prosaically by way of new escapements which reduced the swing of the pendulum. Huygens's clocks had another innovatory feature: maintaining power, which kept the clock going while it was being wound.Pendulums could not be used for portable timepieces, which continued to use balances despite their deficiencies. Robert Hooke was probably the first to apply a spring to the balance, but his efforts were not successful. From his work on the pendulum Huygens was well aware of the conditions necessary for isochronism in a vibrating system, and in January 1675, with a flash of inspiration, he realized that this could be achieved by controlling the oscillations of the balance with a spiral spring, an arrangement that is still used in mechanical watches. The first model was made for Huygens in Paris by the clockmaker Isaac Thuret, who attempted to appropriate the invention and patent it himself. Huygens had for many years been trying unsuccessfully to adapt the pendulum clock for use at sea (in order to determine longitude), and he hoped that a balance-spring timekeeper might be better suited for this purpose. However, he was disillusioned as its timekeeping proved to be much more susceptible to changes in temperature than that of the pendulum clock.[br]Principal Honours and DistinctionsFRS 1663. Member of the Académie Royale des Sciences 1666.BibliographyFor his complete works, see Oeuvres complètes de Christian Huygens, 1888–1950, 22 vols, The Hague.1658, Horologium, The Hague; repub., 1970, trans. E.L.Edwardes, AntiquarianHorology 7:35–55 (describes the pendulum clock).1673, Horologium Oscillatorium, Paris; repub., 1986, The Pendulum Clock or Demonstrations Concerning the Motion ofPendula as Applied to Clocks, trans.R.J.Blackwell, Ames.The balance spring watch was first described in Journal des Sçavans 25 February 1675, and translated in Philosophical Transactions of the Royal Society (1675) 4:272–3.Further ReadingH.J.M.Bos, 1972, Dictionary of Scientific Biography, ed. C.C.Gillispie, Vol. 6, New York, pp. 597–613 (for a fuller account of his life and scientific work, but note the incorrect date of his death).R.Plomp, 1979, Spring-Driven Dutch Pendulum Clocks, 1657–1710, Schiedam (describes Huygens's application of the pendulum to the clock).S.A.Bedini, 1991, The Pulse of Time, Florence (describes Galileo's contribution of the pendulum to the clock).J.H.Leopold, 1982, "L"Invention par Christiaan Huygens du ressort spiral réglant pour les montres', Huygens et la France, Paris, pp. 154–7 (describes the application of the balance spring to the watch).A.R.Hall, 1978, "Horology and criticism", Studia Copernica 16:261–81 (discusses Hooke's contribution).DV -
107 Mackenzie, Sir James
SUBJECT AREA: Medical technology[br]b. 12 April 1853 Scone, Perthshire, Scotlandd. 26 January 1925 London, England[br]Scottish physician and clinical researcher, inventor of the "polygraph" for the investigation of normal and abnormal cardiac rhythms.[br]Mackenzie graduated in medicine from Edinburgh University in 1878. The next year he moved to a practice in Burnley, Lancashire, where he began the exhaustive clinical studies into irregularities of cardiac rhythm that he was to continue for the rest of his life. In 1907 he moved to London and in 1913 was appointed physician to the London Hospital.It was while engaged in the heavy industrial practice in Burnley that he developed, with the aid of a Lancashire watchmaker, the "polygraph" apparatus, which by recording vascular pulses permitted analysis of cardiac function and performance. He also investigated herpes zoster (shingles) and was a pioneer in the treatment of heart disease with digitalis. He himself suffered from angina pectoris for the last fifteen years of his life and his views on the condition were published in a book in 1923. When shown the electrocardiogram (ECG) machine of Einthoven, he expressed reservations as to its future utility.[br]Principal Honours and DistinctionsKnighted 1915. FRS 1915.Bibliography1902, The Study of the Pulse, Edinburgh. 1908, Diseases of the Heart, London. 1925, Heart, London.Further ReadingM.Wilson, 1926, The Beloved Physician: Sir James Mackenzie.MG -
108 Tossach, William
SUBJECT AREA: Medical technology[br]b. c. 1700 probably Perthshire, Scotlandd. after 1771 Alloa, Scotland[br]Scottish surgeon, the first to report a case of artificial respiration by mouth.[br]Little is known of Tossach (a Tossach matriculated at Glasgow University in 1727), but in 1771 he published an account of the resuscitation of a miner, James Blair, who had been rescued from a coal-mine fire. Tossach found "there was not the least pulse in either heart or arteries and not the least breathing could be observed; so that he was in all appearance dead, I applied my mouth close to his, and blowed my breath as strong as I could: but having neglected to close his nostrils all the air came out of them: Wherefore taking hold of them with one hand and holding my other on his breast at the left pap I blew again my breath as strong as I could, raising his chest fully with it; and immediately I felt six or seven very quick beats of the heart." Blair recovered consciousness in an hour and walked home within four.[br]Bibliography1771, "A man dead in appearance recovered by distending the lungs with air", Medical Essays and Observations, Edinburgh.Further Reading1794, Transactions of the Royal Humane Society from 1774–1784, London. J.P.Griffin, 1990, "The origins of the Royal Humane Society", Journal of the RoyalSociety of Medicine 83.MG
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