principal+lines

SUBJECT AREA: Broadcasting, Electronics and information technology, Recording

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After education in Hungary and a period as an assistant at the Technische Hochschule, Berlin, Goldmark moved to England, where he joined Pye of Cambridge and worked on an experimental thirty-line television system using a cathode ray tube (CRT) for the display. In 1936 he moved to the USA to work at Columbia Broadcasting Laboratories. There, with monochrome television based on the CRT virtually a practical proposition, he devoted his efforts to finding a way of producing colour TV images: in 1940 he gave his first demonstration of a working system. There then followed a series of experimental field-sequential colour TV systems based on segmented red, green and blue colour wheels and drums, where the problem was to find an acceptable compromise between bandwidth, resolution, colour flicker and colour-image breakup. Eventually he arrived at a system using a colour wheel in combination with a CRT containing a panchromatic phosphor screen, with a scanned raster of 405 lines and a primary colour rate of 144 fields per second. Despite the fact that the receivers were bulky, gave relatively poor, dim pictures and used standards totally incompatible with the existing 525-line, sixty fields per second interlaced monochrome (black and white) system, in 1950 the Federal Communications Commission (FCC), anxious to encourage postwar revival of the industry, authorized the system for public broadcasting. Within eighteen months, however, bowing to pressure from the remainder of the industry, which had formed its own National Television Systems Committee (NTSC) to develop a much more satisfactory, fully compatible system based on the RCA three-gun shadowmask CRT, the FCC withdrew its approval.

While all this was going on, Goldmark had also been working on ideas for overcoming the poor reproduction, noise quality, short playing-time (about four minutes) and limited robustness and life of the long-established 78 rpm 12 in. (30 cm) diameter shellac gramophone record. The recent availability of a new, more robust, plastic material, vinyl, which had a lower surface noise, enabled him in 1948 to reduce the groove width some three times to 0.003 in. (0.0762 mm), use a more lightly loaded synthetic sapphire stylus and crystal transducer with improved performance, and reduce the turntable speed to 33 1/3 rpm, to give thirty minutes of high-quality music per side. This successful development soon led to the availability of stereophonic recordings, based on the ideas of Alan Blumlein at EMI in the 1930s.

In 1950 Goldmark became a vice-president of CBS, but he still found time to develop a scan conversion system for relaying television pictures to Earth from the Lunar Orbiter spacecraft. He also almost brought to the market a domestic electronic video recorder (EVR) system based on the thermal distortion of plastic film by separate luminance and coded colour signals, but this was overtaken by the video cassette recorder (VCR) system, which uses magnetic tape.

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See also: Baird, John Logie

SUBJECT AREA: Land transport, Railways and locomotives

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Gresley was the son of the Rector of Netherseale, Derbyshire; he was educated at Marlborough and by the age of 13 was skilled at making sketches of locomotives. In 1893 he became a pupil of F.W. Webb at Crewe works, London \& North Western Railway, and in 1898 he moved to Horwich works, Lancashire \& Yorkshire Railway, to gain drawing-office experience under J.A.F.Aspinall, subsequently becoming Foreman of the locomotive running sheds at Blackpool. In 1900 he transferred to the carriage and wagon department, and in 1904 he had risen to become its Assistant Superintendent. In 1905 he moved to the Great Northern Railway, becoming Superintendent of its carriage and wagon department at Doncaster under H.A. Ivatt. In 1906 he designed and produced a bogie luggage van with steel underframe, teak body, elliptical roof, bowed ends and buckeye couplings: this became the prototype for East Coast main-line coaches built over the next thirty-five years. In 1911 Gresley succeeded Ivatt as Locomotive, Carriage \& Wagon Superintendent. His first locomotive was a mixed-traffic 2–6–0, his next a 2–8–0 for freight. From 1915 he worked on the design of a 4–6–2 locomotive for express passenger traffic: as with Ivatt's 4 4 2s, the trailing axle would allow the wide firebox needed for Yorkshire coal. He also devised a means by which two sets of valve gear could operate the valves on a three-cylinder locomotive and applied it for the first time on a 2–8–0 built in 1918. The system was complex, but a later simplified form was used on all subsequent Gresley three-cylinder locomotives, including his first 4–6–2 which appeared in 1922. In 1921, Gresley introduced the first British restaurant car with electric cooking facilities.

With the grouping of 1923, the Great Northern Railway was absorbed into the London \& North Eastern Railway and Gresley was appointed Chief Mechanical Engineer. More 4–6– 2s were built, the first British class of such wheel arrangement. Modifications to their valve gear, along lines developed by G.J. Churchward, reduced their coal consumption sufficiently to enable them to run non-stop between London and Edinburgh. So that enginemen might change over en route, some of the locomotives were equipped with corridor tenders from 1928. The design was steadily improved in detail, and by comparison an experimental 4–6–4 with a watertube boiler that Gresley produced in 1929 showed no overall benefit. A successful high-powered 2–8–2 was built in 1934, following the introduction of third-class sleeping cars, to haul 500-ton passenger trains between Edinburgh and Aberdeen.

In 1932 the need to meet increasing road competition had resulted in the end of a long-standing agreement between East Coast and West Coast railways, that train journeys between London and Edinburgh by either route should be scheduled to take 8 1/4 hours. Seeking to accelerate train services, Gresley studied high-speed, diesel-electric railcars in Germany and petrol-electric railcars in France. He considered them for the London \& North Eastern Railway, but a test run by a train hauled by one of his 4–6–2s in 1934, which reached 108 mph (174 km/h), suggested that a steam train could better the railcar proposals while its accommodation would be more comfortable. To celebrate the Silver Jubilee of King George V, a high-speed, streamlined train between London and Newcastle upon Tyne was proposed, the first such train in Britain. An improved 4–6–2, the A4 class, was designed with modifications to ensure free running and an ample reserve of power up hill. Its streamlined outline included a wedge-shaped front which reduced wind resistance and helped to lift the exhaust dear of the cab windows at speed. The first locomotive of the class, named Silver Link, ran at an average speed of 100 mph (161 km/h) for 43 miles (69 km), with a maximum speed of 112 1/2 mph (181 km/h), on a seven-coach test train on 27 September 1935: the locomotive went into service hauling the Silver Jubilee express single-handed (since others of the class had still to be completed) for the first three weeks, a round trip of 536 miles (863 km) daily, much of it at 90 mph (145 km/h), without any mechanical troubles at all. Coaches for the Silver Jubilee had teak-framed, steel-panelled bodies on all-steel, welded underframes; windows were double glazed; and there was a pressure ventilation/heating system. Comparable trains were introduced between London Kings Cross and Edinburgh in 1937 and to Leeds in 1938.

Gresley did not hesitate to incorporate outstanding features from elsewhere into his locomotive designs and was well aware of the work of André Chapelon in France. Four A4s built in 1938 were equipped with Kylchap twin blast-pipes and double chimneys to improve performance still further. The first of these to be completed, no. 4468, Mallard, on 3 July 1938 ran a test train at over 120 mph (193 km/h) for 2 miles (3.2 km) and momentarily achieved 126 mph (203 km/h), the world speed record for steam traction. J.Duddington was the driver and T.Bray the fireman. The use of high-speed trains came to an end with the Second World War. The A4s were then demonstrated to be powerful as well as fast: one was noted hauling a 730-ton, 22-coach train at an average speed exceeding 75 mph (120 km/h) over 30 miles (48 km). The war also halted electrification of the Manchester-Sheffield line, on the 1,500 volt DC overhead system; however, anticipating eventual resumption, Gresley had a prototype main-line Bo-Bo electric locomotive built in 1941. Sadly, Gresley died from a heart attack while still in office.

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See also: Bulleid, Oliver Vaughan Snell

SUBJECT AREA: Broadcasting, Electronics and information technology, Telecommunications

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Hartley obtained his BA in 1909 from the University of Utah, then gained a Rhodes Scholarship to Oxford University, England. After obtaining a further BA and a BSc in 1912 and 1913, respectively, he returned to the USA and took a job with the Western Electric Laboratories of the Bell Telephone Company, where he was in charge of radio-receiver development. In 1915 he invented the Hartley oscillator, analogous to that invented by Colpitts. Subsequently he worked on carrier telephony at Western Electric and then at Bell Laboratories. There he concen-trated on information theory, building on the pioneering work of Nyquist, in 1926 publishing his law that related information capacity, frequency bandwidth and time. Forced to give up work in 1929 due to ill health, he returned to Bell in 1939 as a consultant on transmission problems. During the Second World War he worked on various projects, including the use of servo-mechanisms for radar and fire control, and finally retired in 1950.

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SUBJECT AREA: Broadcasting, Telecommunications

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Brought up in poor, almost Dickensian, circumstances, at the age of 13 years Heaviside, a nephew by marriage of Sir Charles Wheatstone, went to Camden House Grammar School. There he won a medal for science, but he was forced to leave because his parents could not afford the fees. After a year of private study, he began his working life in Newcastle in 1870 as a telegraph operator for an Anglo-Dutch cable company, but he had to give up after only four years because of increasing deafness. He therefore proceeded to spend his time studying theoretical aspects of electrical transmission and communication, and moved to Devon with his parents in 1889. Because the operation of many electrical circuits involves transient phenomena, he found it necessary to develop what he called operational calculus (which was essentially a form of the Laplace transform calculus) in order to determine the response to sudden voltage and current changes. In 1893 he suggested that the distortion that occurred on long-distance telephone lines could be reduced by adding loading coils at regular intervals, thus creating a matched-transmission line. Between 1893 and 1912 he produced a series of writings on electromagnetic theory, in one of which, anticipating a conclusion of Einstein's special theory of relativity, he put forward the idea that the mass of an electric charge increases with its velocity. When it was found that despite the curvature of the earth it was possible to communicate over very great distances using radio signals in the so-called "short" wavebands, Heaviside suggested the presence of a conducting layer in the ionosphere that reflected the waves back to earth. Since a similar suggestion had been made almost at the same time by Arthur Kennelly of Harvard, this layer became known as the Kennelly-Heaviside layer.

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See also: Appleton, Sir Edward Victor

SUBJECT AREA: Electricity, Electronics and information technology, Telecommunications

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At the age of 17 Hertz entered the Gelehrtenschule of the Johaneums in Hamburg, but he left the following year to obtain practical experience for a year with a firm of engineers in Frankfurt am Main. He then spent six months at the Dresden Technical High School, followed by year of military service in Berlin. At this point he decided to switch from engineering to physics, and after a year in Munich he studied physics under Helmholtz at the University of Berlin, gaining his PhD with high honours in 1880. From 1883 to 1885 he was a privat-dozent at Kiel, during which time he studied the electromagnetic theory of James Clerk Maxwell. In 1885 he succeeded to the Chair in Physics at Karlsruhe Technical High School. There, in 1887, he constructed a rudimentary transmitter consisting of two 30 cm (12 in.) rods with metal balls separated by a 7.5 mm (0.3 in.) gap at the inner ends and metallic plates at the outer ends, the whole assembly being mounted at the focus of a large parabolic metal mirror and the two rods being connected to an induction coil. At the other side of his laboratory he placed a 70 cm (27½ in.) diameter wire loop with a similar air gap at the focus of a second metal mirror. When the induction coil was made to create a spark across the transmitter air gap, he found that a spark also occurred at the "receiver". By a series of experiments he was not only able to show that the invisible waves travelled in straight lines and were reflected by the parabolic mirrors, but also that the vibrations could be refracted like visible light and had a similar wavelength. By this first transmission and reception of radio waves he thus confirmed the theoretical predictions made by Maxwell some twenty years earlier. It was probably in his experiments with this apparatus in 1887 that Hertz also observed that the voltage at which a spark was able to jump a gap was significantly reduced by the presence of ultraviolet light. This so-called photoelectric effect was subsequently placed on a theoretical basis by Albert Einstein in 1905. In 1889 he became Professor of Physics at the University of Bonn, where he continued to investigate the nature of electric discharges in gases at low pressure until his death after a long and painful illness. In recognition of his measurement of radio and other waves, the international unit of frequency of an oscillatory wave, the cycle per second, is now universally known as the Hertz.

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See also: Heaviside, Oliver

SUBJECT AREA: Ports and shipping

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King was educated at the High School of Glasgow, and then served an apprenticeship with the Port Glasgow shipyard of Russell \& Co. This was followed by experience in drawing offices in Port Glasgow, Hull and finally in Belfast, where he was responsible for the separate White Star Line drawing office of Harland \& Wolff Ltd, which was then producing the plans for the Atlantic passenger liners Majestic and Teutonic. Following certain unpopular government shipping enactments in 1890, a protest from shipbuilders and shipowners in Ireland, Liverpool and the West of Scotland led to the founding of a new classification society to compete against Lloyd's Register of Shipping. It became known as the British Corporation Register and had headquarters in Glasgow. King was recruited to the staff and by 1903 had become Chief Surveyor, a position he held until his retirement thirty-seven years later. By then the Register was a world leader, with hundreds of thousands of tons of shipping on its books; it acted as consultant to many governments and international agencies. Throughout his working life, King did everything in his power to quantify the risks and problems of ship operation: his contribution to the Load Lines Convention of 1929 was typical, and few major enactments in shipping were designed without his approval. During the inter-war period the performance of the British Corporation outshone that of all rivals, for which King deserved full credit. His especial understanding was for steel structures, and in this respect he ensured that the British Corporation enabled owners to build ships of strengths equal to any others despite using up to 10 per cent less steel within the structure. In 1949 Lloyd's Register of Shipping and the British Corporation merged to form the largest and most influential ship classification society in the world.

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SUBJECT AREA: Paper and printing

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Although reared in a farming community, Lanston was able to develop his mechanical talent. After serving in the American Civil War he secured a clerkship in the Pensions Office in Washington, where he remained for twenty-two years. He studied law in his spare time and was called to the Bar. At the same time, he invented a whole variety of mechanical devices, many of which he patented. Around 1883 Lanston began taking an interest in machines for composing printers' type, probably stimulated by Ottmar Mergenthaler, who was then in Washington and working in this field. Four years' work were rewarded on 7 June 1887 by the grant of a patent, followed by three more, for a machine "to produce justified lines of type". The machine, the Monotype, consisted of two components: first a keyboard unit produced a strip of paper tape with holes punched in patterns corresponding to the characters required; this tape controlled the matrices in the caster, the second and "hot metal" component, from which types were ejected singly and fed to an assembly point until a complete line of type had been formed. Lanston resigned his post and set up the Lanston Type Machine Company in Washington. He laboured for ten years to convert the device defined in his patents into a machine that could be made and used commercially. In 1897 the perfected Monotype appeared. The company was reorganized as the Lanston Monotype Manufacturing Company of Philadelphia, and Lanston devoted himself to promoting and improving the machine. Monotype, with Mergenthaler's Linotype, steadily supplanted hand-setting and the various inadequate mechanical methods that were then in use, and by the 1920s they reigned supreme, until the 1960s, when they themselves began to be superseded by computer-controlled photosetting methods.

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SUBJECT AREA: Land transport, Railways and locomotives

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Sir John MacNeill became a pupil of Thomas Telford and served under him as Superintendent of the Southern Division of the Holyhead Road from London to Shrewsbury. In this capacity he invented a "Road Indicator" or dynamometer. Like other Telford followers, he viewed the advent of railways with some antipathy, but after the death of Telford in 1834 he quickly became involved in railway construction and in 1837 he was retained by the Irish Railway Commissioners to build railways in the north of Ireland (Vignoles received the commission for the south). Much of his subsequent career was devoted to schemes for Irish railways, both those envisaged by the Commissioners and other private lines with more immediately commercial objectives. He was knighted in 1844 on the completion of the Dublin \& Drogheda Railway along the east coast of Ireland. In 1845 MacNeill lodged plans for over 800 miles (1,300 km) of Irish railways. Not all of these were built, many falling victim to Irish poverty in the years after the Famine, but he maintained a large staff and became financially embarrassed. His other schemes included the Grangemouth Docks in Scotland, the Liverpool \& Bury Railway, and the Belfast Waterworks, the latter completed in 1843 and subsequently extended by Bateman.

MacNeill was an engineer of originality, being the person who introduced iron-lattice bridges into Britain, employing the theoretical and experimental work of Fairbairn and Eaton Hodgkinson (the Boyne Bridge at Drogheda had two such spans of 250ft (76m) each). He also devised the Irish railway gauge of 5 ft 2 in. (1.57 m). Consulted by the Board of Trinity College, Dublin, regarding a School of Engineering in 1842, he was made an Honorary LLD of the University and appointed the first Professor of Civil Engineering, but he relinquished the chair to his assistant, Samuel Downing, in 1846. MacNeill was a large and genial man, but not, we are told, "of methodical and business habit": he relied heavily on his subordinates. Blindness obliged him to retire from practice several years before his death. He was an early member of the Institution of Civil Engineers, joining in 1827, and was elected a Fellow of the Royal Society in 1838.

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SUBJECT AREA: Civil engineering, Land transport, Railways and locomotives

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Palmer was an assistant to Thomas Telford for ten years from 1816. In 1818 he arranged a meeting of young engineers from which the Institution of Civil Engineers originated. In the early 1820s he invented a monorail system, the first of its kind, in which a single rail of wood, with an iron strip spiked on top to form a running surface, was supported on posts. Wagon bodies were supported pannier fashion from a frame attached to grooved wheels and were propelled by men or horses. An important object was to minimize friction, and short lines were built on this principle at Deptford and Cheshunt. In 1826 Palmer was appointed Resident Engineer to the London Docks and was responsible for the construction of many of them. He was subsequently consulted about many important engineering works.

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See also: Lartigue, Charles François Marie-Thérèse

SUBJECT AREA: Electricity, Ports and shipping

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The youngest son of the Earl of Rosse, he came from a family well known in scientific circles, the six boys growing up in an intellectual atmosphere at Birr Castle, the ancestral home in Ireland, where a forge and large workshop were available to them. Charles, like his brothers, did not go to school but was educated by private tutors of the character of Sir Robert Ball, this type of education being interspersed with overseas holiday trips to France, Holland, Belgium and Spain in the family yacht. In 1871, at the age of 17, he went to Trinity College, Dublin, and after two years he went on to St John's College, Cambridge. This was before the Engineering School had opened, and Parsons studied mechanics and mathematics.

In 1877 he was apprenticed to W.G.Armstrong \& Co. of Elswick, where he stayed for four years, developing an epicycloidal engine that he had designed while at Cambridge. He then moved to Kitson \& Co. of Leeds, where he went half shares in a small experimental shop working on rocket propulsion for torpedoes.

In 1887 he married Katherine Bethell, who contracted rheumatic fever from early-morning outdoor vigils with her husband to watch his torpedo experiments while on their honeymoon! He then moved to a partnership in Clarke, Chapman \& Co. at Gateshead. There he joined the electrical department, initially working on the development of a small, steam-driven marine lighting set. This involved the development of either a low-speed dynamo, for direct coupling to a reciprocating engine, or a high-speed engine, and it was this requirement that started Parsons on the track of the steam turbine. This entailed many problems such as the running of shafts at speeds of up to 40,000 rpm and the design of a DC generator for 18,000 rpm. He took out patents for both the turbine and the generator on 23 April 1884. In 1888 he dissolved his partnership with Clarke, Chapman \& Co. to set up his own firm in Newcastle, leaving his patents with the company's owners. This denied him the use of the axial-flow turbine, so Parsons then designed a radial-flow layout; he later bought back his patents from Clarke, Chapman \& Co. His original patent had included the use of the steam turbine as a means of marine propulsion, and Parsons now set about realizing this possibility. He experimented with 2 ft (61 cm) and 6 ft (183 cm) long models, towed with a fishing line or, later, driven by a twisted rubber cord, through a single-reduction set of spiral gearing.

The first trials of the Turbinia took place in 1894 but were disappointing due to cavitation, a little-understood phenomenon at the time. He used an axial-flow turbine of 2,000 shp running at 2,000 rpm. His work resulted in a far greater understanding of the phenomenon of cavitation than had hitherto existed. Land turbines of up to 350 kW (470 hp) had meanwhile been built. Experiments with the Turbinia culminated in a demonstration which took place at the great Naval Review of 1897 at Spithead, held to celebrate Queen Victoria's Diamond Jubilee. Here, the little Turbinia darted in and out of the lines of heavy warships and destroyers, attaining the unheard of speed of 34.5 knots. The following year the Admiralty placed their first order for a turbine-driven ship, and passenger vessels started operation soon after, the first in 1901. By 1906 the Admiralty had moved over to use turbines exclusively. These early turbines had almost all been direct-coupled to the ship's propeller shaft. For optimum performance of both turbine and propeller, Parsons realized that some form of reduction gearing was necessary, which would have to be extremely accurate because of the speeds involved. Parsons's Creep Mechanism of 1912 ensured that any errors in the master wheel would be distributed evenly around the wheel being cut.

Parsons was also involved in optical work and had a controlling interest in the firm of Ross Ltd of London and, later, in Sir Howard Grubb \& Sons. He he was an enlightened employer, originating share schemes and other benefits for his employees.

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SUBJECT AREA: Mechanical, pneumatic and hydraulic engineering

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Jesse Ramsden was the son of an innkeeper but received a good general education: after attending the free school at Halifax, he was sent at the age of 12 to his uncle for further study, particularly in mathematics. At the age of 16 he was apprenticed to a cloth-worker in Halifax and on completion of the apprenticeship in 1755 he moved to London to work as a clerk in a cloth warehouse. In 1758 he became an apprentice in the workshop of a London mathematical instrument-maker named Burton. He quickly gained the skill, particularly in engraving, and by 1762 he was able to set up on his own account. He married in 1765 or 1766 the youngest daughter of the optician John Dollond FRS (1706– 61) and received a share of Dollond's patent for making achromatic lenses.

Ramsden's experience and reputation increased rapidly and he was generally regarded as the leading instrument-maker of his time. He opened a shop in the Haymarket and transferred to Piccadilly in 1775. His staff increased to about sixty workers and apprentices, and by 1789 he had constructed nearly 1,000 sextants as well as theodolites, micrometers, balances, barometers, quadrants and other instruments.

One of Ramsden's most important contributions to precision measurement was his development of machines for obtaining accurate division of angular and linear scales. For this work he received a premium from the Commissioners of the Board of Longitude, who published his descriptions of the machines. For the trigonometrical survey of Great Britain, initiated by General William Roy FRS (1726–90) and continued by the Board of Ordnance, Ramsden supplied a 3 ft (91 cm) theodolite and steel measuring chains, and was also engaged to check the glass tubes used to measure the fundamental base line.

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SUBJECT AREA: Land transport, Railways and locomotives

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John Urpeth Rastrick, son of an engineer, was initially articled to his father and then moved to Ketley Ironworks, Shropshire, c. 1801. In 1808 he entered into a partnership with John Hazledine at Bridgnorth, Shropshire: Hazledine and Rastrick built many steam engines to the designs of Richard Trevithick, including the demonstration locomotive Catch-Me-Who-Can. The firm also built iron bridges, notably the bridge over the River Wye at Chepstow in 1815–16.

Between 1822 and 1826 the Stratford \& Moreton Railway was built under Rastrick's direction. Malleable iron rails were laid, in one of the first instances of their use. They were supplied by James Foster of Stourbridge, with whom Rastrick went into partnership after the death of Hazledine. In 1825 Rastrick was one of a team of engineers sent by the committee of the proposed Liverpool \& Manchester Railway (L \& MR) to carry out trials of locomotives built by George Stephenson on the Killingworth Waggonway. Early in 1829 the directors of the L \& MR, which was by then under construction, sent Rastrick and James Walker to inspect railways in North East England and report on the relative merits of steam locomotives and fixed engines with cable haulage. They reported, rather hesitantly, in favour of the latter, particularly the reciprocal system of Benjamin Thompson. In consequence the Rainhill Trials, at which Rastrick was one of the judges, were held that October. In 1829 Rastrick constructed the Shutt End colliery railway in Worcestershire, for which Foster and Rastrick built the locomotive Agenoria; this survives in the National Railway Museum. Three similar locomotives were built to the order of Horatio Allen for export to the USA.

From then until he retired in 1847 Rastrick found ample employment surveying railways, appearing as a witness before Parliamentary committees, and supervising construction. Principally, he surveyed the southern part of the Grand Junction Railway, which was built for the most part by Joseph Locke, and the line from Manchester to Crewe which was eventually built as the Manchester \& Birmingham Railway. The London \& Brighton Railway (Croydon to Brighton) was his great achievement: built under Rastrick's supervision between 1836 and 1840, it included three long tunnels and the magnificent Ouse Viaduct. In 1845 he was Engineer to the Gravesend \& Rochester Railway, the track of which was laid through the Thames \& Medway Canal's Strood Tunnel, partly on the towpath and partly on a continuous staging over the water.

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See also: Stephenson, Robert

SUBJECT AREA: Electronics and information technology

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After early education at the Jonkoping elementary school and the Weixo Gymnasium, George Scheutz entered the University of Lund, gaining a degree in law in 1805. Following five years' legal work, he moved to Stockholm in 1811 to work at the Supreme Court and, in 1814, as a military auditor. In 1816, he resigned, bought a printing business and became editor of a succession of industrial and technical journals, during which time he made inventions relating to the press. It was in 1830 that he learned from the Edinburgh Review of Babbage's ideas for a difference engine and started to make one from wood, pasteboard and wire. In 1837 his 15-yearold student son, Edvard Raphael Scheutz, offered to make it in metal, and by 1840 they had a working machine with two five-digit registers, which they increased the following year and then added a printer. Obtaining a government grant in 1851, by 1853 they had a fully working machine, now known as Swedish Difference Engine No. 1, which with an experienced operator could generate 120 lines of tables per hour and was used to calculate the logarithms of the numbers 1 to 10,000 in under eighty hours. This was exhibited in London and then at the Paris Great Exhibition, where it won the Gold Medal. It was subsequently sold to the Dudley Observatory in Albany, New York, for US$5,000 and is now in a Chicago museum.

In England, the British Registrar-General, wishing to produce new tables for insurance companies, and supported by the Astronomer Royal, arranged for government finance for construction of a second machine (Swedish Difference Engine No. 2). Comprising over 1,000 working parts and weighing 1,000 lb (450 kg), this machine was used to calculate over 600 tables. It is now in the Science Museum.

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SUBJECT AREA: Medical technology, Photography, film and optics

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Snellen took his degree in medicine at Utrecht in 1857, and after continued study was appointed Lecturer in Ophthalmology and Surgeon to the Hospital for Diseases of the Eye. In 1877 he succeeded Franciscus Cornelius Donders, an outstanding figure in the development of the understanding of the optics and physiology of vision, as Professor. He held this post until 1899 when he was succeeded by his son.

Although involved in virtually all aspects of the speciality, he particularly laid the basis for the scientific recording of visual acuity with the publication of his Optotypes in 1862. Optotypes were based on the concept of an average standard of vision permitting the discrimination of separate objects which subtended an angle of one minute of arc on the retina. While the concept does not take into account aspects of vision such as perception, it has stood the test of time in terms of practicality, even when abstract figures such as Landolt's rings replace the lines of single letters of the original.

Snellen originated many other advances of a surgical nature, his procedure for eyelid deformity is still practised, and he developed the use of glass in the manufacture of artificial eyes.

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SUBJECT AREA: Chemical technology, Synthetic materials

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Staudinger studied chemistry at the universities of Halle, Darmstadt and Munich, originally as a preparation for botanical studies, but chemistry claimed his full attention. He followed an academic career, with professorships at Karlsruhe in 1908, Zurich in 1912 and Freiberg from 1926 until his retirement in 1951. Staudinger began his work as an organic chemist by following well-established lines of research, but from 1920 he struck out in a new direction. Until that time, rubber and other apparently non-crystalline materials with high molecular weight were supposed to consist of a disordered collection of small molecules. Staudinger investigated the structure of rubber and realized that it was made up of very large molecules with many basic groups of atoms held together by normal chemical bonds. Substances formed in this way are known as "polymers". Staudinger's views first met with opposition, but he developed methods of determining the molecular weights of these "high polymers". Finally, the introduction of X-ray crystallographic investigation of chemical structure confirmed his views. This discovery has proved to be the basis of a new branch of chemistry with momentous consequences for industry. From it stemmed the synthetic rubber, plastics, fibres, adhesives and other industries, with all their multifarious applications in everyday life. The Staudinger equation, linking viscosity with molecular weight, is still widely used, albeit with some reservations, in the polymer industry.

During the 1930s, Staudinger turned his attention to biopolymers and foresaw the discovery some twenty years later that these macromolecules were the building blocks of life. In 1953 he belatedly received the Nobel Prize in Chemistry.

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SUBJECT AREA: Photography, film and optics

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Educated at Harrow, where he first showed an interest in science, and at Cambridge, Talbot was an outstanding scholar and a formidable mathematician. He published over fifty scientific papers and took out twelve English patents. His interests outside the field of science were also wide and included Assyriology, etymology and the classics. He was briefly a Member of Parliament, but did not pursue a parliamentary career.

Talbot's invention of photography arose out of his frustrating attempts to produce acceptable pencil sketches using popular artist's aids, the camera discura and camera lucida. From his experiments with the former he conceived the idea of placing on the screen a paper coated with silver salts so that the image would be captured chemically. During the spring of 1834 he made outline images of subjects such as leaves and flowers by placing them on sheets of sensitized paper and exposing them to sunlight. No camera was involved and the first images produced using an optical system were made with a solar microscope. It was only when he had devised a more sensitive paper that Talbot was able to make camera pictures; the earliest surviving camera negative dates from August 1835. From the beginning, Talbot noticed that the lights and shades of his images were reversed. During 1834 or 1835 he discovered that by placing this reversed image on another sheet of sensitized paper and again exposing it to sunlight, a picture was produced with lights and shades in the correct disposition. Talbot had discovered the basis of modern photography, the photographic negative, from which could be produced an unlimited number of positives. He did little further work until the announcement of Daguerre's process in 1839 prompted him to publish an account of his negative-positive process. Aware that his photogenic drawing process had many imperfections, Talbot plunged into further experiments and in September 1840, using a mixture incorporating a solution of gallic acid, discovered an invisible latent image that could be made visible by development. This improved calotype process dramatically shortened exposure times and allowed Talbot to take portraits. In 1841 he patented the process, an exercise that was later to cause controversy, and between 1844 and 1846 produced The Pencil of Nature, the world's first commercial photographically illustrated book.

Concerned that some of his photographs were prone to fading, Talbot later began experiments to combine photography with printing and engraving. Using bichromated gelatine, he devised the first practicable method of photo engraving, which was patented as Photoglyphic engraving in October 1852. He later went on to use screens of gauze, muslin and finely powdered gum to break up the image into lines and dots, thus anticipating modern photomechanical processes.

Talbot was described by contemporaries as the "Father of Photography" primarily in recognition of his discovery of the negative-positive process, but he also produced the first photomicrographs, took the first high-speed photographs with the aid of a spark from a Leyden jar, and is credited with proposing infra-red photography. He was a shy man and his misguided attempts to enforce his calotype patent made him many enemies. It was perhaps for this reason that he never received the formal recognition from the British nation that his family felt he deserved.

[br]

SUBJECT AREA: Electronics and information technology

[br]

[br]

[br]

Educated at King Edward VI Grammar School, Stourbridge, where he began to make radio sets and read Wireless World, Wilkes went to St John's College, Cambridge, in 1931, graduating as a Wrangler in the Mathematical Tripos in 1934. He then carried out research at the Cavendish Laboratory, becoming a demonstrator in 1937. During the Second World War he worked on radar, differential analysers and operational research at the Bawdsey Research Station and other air-defence establishments. In 1945 he returned to Cambridge as a lecturer and as Acting Director of the Mathematical (later Computer) Laboratory, serving as Director from 1946 to 1970.

During the late 1940s, following visits to the USA for computer courses and to see the ENIAC computer, with the collaboration of colleagues he constructed the Cambridge University digital computer EDSAC (for Electronic Delay Storage Automatic Computer), using ultrasonic delay lines for data storage. In the mid-1950s a second machine, EDSAC2, was constructed using a magnetic-core memory. In 1965 he became Professor of Computer Technology. After retirement he worked for the Digital Electronic Corporation (DEC) from 1981 to 1986, serving also as Adjunct Professor of Computer Science and Electrical Engineering at the Massachusetts Institute of Technology from 1981 to 1985. In 1990 he became a research strategy consultant to the Olivetti Research Directorate.

[br]

See also: Forrester, Jay Wright; Goldstine, Herman H.; Strachey, Christopher

 

сети
Система линий передачи и распределения перекрестно соединенная и эксплуатируемая, чтобы дать возможность осуществлять множественные поставки электроэнергии в любой точке сетей. Сети обычно устанавливаются в городских зонах. Они позволяют быстро восстановить поставки электроэнергии потребителям, переключив их на другую цепь (Термины Рабочей Группы правового регулирования ЭРРА).
[Англо-русский глосcарий энергетических терминов ERRA]

EN

network
A system of transmission and distribution lines cross-connected and operated to permit multiple power supply to any principal point on it. A network is usually installed in urban areas. It makes it possible to restore power quickly to customers by switching them to another circuit (ERRA Legal Regulation Working Group Terms).
[Англо-русский глосcарий энергетических терминов ERRA]

Тематики

• энергетика в целом

EN

• network

 

график сетевой
Документ проекта организации строительства (ПОС), с помощью которого осуществляется управление ходом строительных работ на крупных объектах, представляющий собой технологически связанную сеть графов, вершинами которых являются события (начало и завершение работы), а рёбрами - процессы по подготовке событий
[Терминологический словарь по строительству на 12 языках (ВНИИИС Госстроя СССР)]

Тематики

• сетевое планирование, моделирование
• строительство в целом

EN

• network
• network diagram

DE

• Netzplan
• Netzwerk

FR

• modèle de réseau

 

компьютерная сеть
Совокупность рабочих станций, соединенных между собой с помошью сетевого оборудования и среды передачи данных.
Примеры сочетаний:
network access - доступ к компьютерной сети
network backbone - сетевая магистраль
network database - сетевая СУБД - СУБД, поддерживающая работу в распределенной вычислительной сети
network ID - идентификатор сети - часть IP-адреса, идентифицирующая группу компьютеров и устройств, размещенных в одной локальной сети
network interface - сетевой интерфейс - интерфейс подключения компьютера к локальной сети
network latency - сетевая задержка - время, необходимое для пересылки данных между двумя компьютерами в сети
network transparency - прозрачность сети - свойство ОС или другой службы, позволяющее пользователю обращаться по компьютерной сети к удаленному ресурсу без необходимости знать, локальный он или удаленный.
[ http://www.morepc.ru/dict/]

Тематики

• сети вычислительные

EN

• network

 

расчётная или опытная схема
—
[ http://slovarionline.ru/anglo_russkiy_slovar_neftegazovoy_promyishlennosti/]

Тематики

• нефтегазовая промышленность

EN

• network

 

решетчатая система
решетчатое устройство
—
[ http://slovarionline.ru/anglo_russkiy_slovar_neftegazovoy_promyishlennosti/]

Тематики

• нефтегазовая промышленность

Синонимы

• решетчатое устройство

EN

• network

 

сети
Система линий передачи и распределения перекрестно соединенная и эксплуатируемая, чтобы дать возможность осуществлять множественные поставки электроэнергии в любой точке сетей. Сети обычно устанавливаются в городских зонах. Они позволяют быстро восстановить поставки электроэнергии потребителям, переключив их на другую цепь (Термины Рабочей Группы правового регулирования ЭРРА).
[Англо-русский глосcарий энергетических терминов ERRA]

EN

network
A system of transmission and distribution lines cross-connected and operated to permit multiple power supply to any principal point on it. A network is usually installed in urban areas. It makes it possible to restore power quickly to customers by switching them to another circuit (ERRA Legal Regulation Working Group Terms).
[Англо-русский глосcарий энергетических терминов ERRA]

Тематики

• энергетика в целом

EN

• network

 

сеть 
1. Соединение группы узлов (компьютеров или других устройств).
2. Группа точек, узлов или станций, соединенных коммуникационными каналами и набор оборудования, обеспечивающего соединение станций и передачу между ними информации. Сеть может состоять из любой комбинации локальных (ЛВС) и распределенных (WAN) сетей. 
[ http://www.lexikon.ru/dict/net/index.html]

Тематики

• сети вычислительные

EN

• network

 

сеть
Совокупность станций, входящих в состав данной системы. См. ergodic Markov ~, hypothetical reference ~, Markov ~.
[Л.М. Невдяев. Телекоммуникационные технологии. Англо-русский толковый словарь-справочник. Под редакцией Ю.М. Горностаева. Москва, 2002]

сеть
Ориентированный конечный связный граф без контуров, имеющий начальную точку (“источник”) и конечную точку (“сток”). Как любой граф, С. может быть представлена в различных формах, одной из которых является сетевой график (“графическое представление С.”), другой — матрица связей между ее элементами (матричное представление С.). Часто термин “С.” употребляется также как синоним термина сетевой график, а иногда — и термина граф.
[ http://slovar-lopatnikov.ru/]

Тематики

• экономика
• электросвязь, основные понятия

EN

• chain
• network

 

сеть
Сеть маршрутов между определенными (узловыми) точками. Маршрут – это связующее звено между двумя узлами, являющимися в свою очередь частью большей сети железных дорог и автодорог, а также воздушных и морских коридоров.
[Департамент лингвистических услуг Оргкомитета «Сочи 2014». Глоссарий терминов]

EN

network
Framework of routes within a system of locations, identified as nodes. A route is a single link between two nodes that are part of a larger network that can refer to tangible routes such as roads and rails, or less tangible routes such as air and sea corridors.
[Департамент лингвистических услуг Оргкомитета «Сочи 2014». Глоссарий терминов]

Тематики

• спорт (службы Игр)

EN

• network

 

сеть наблюдений
сеть опорных пунктов
—
[ http://slovarionline.ru/anglo_russkiy_slovar_neftegazovoy_promyishlennosti/]

Тематики

• нефтегазовая промышленность

Синонимы

• сеть опорных пунктов

EN

• network

 

сеть электрических линий или проводов
—
[ http://slovarionline.ru/anglo_russkiy_slovar_neftegazovoy_promyishlennosti/]

Тематики

• нефтегазовая промышленность

EN

• network

 

сеть энергоснабжения
сеть электропитания
—
[Я.Н.Лугинский, М.С.Фези-Жилинская, Ю.С.Кабиров. Англо-русский словарь по электротехнике и электроэнергетике, Москва, 1999 г.]

Тематики

• электротехника, основные понятия

Синонимы

• сеть электропитания

EN

• network
• electrical network
• power network

 

сеть, обеспечивающая услуги общего пользования
—
[Л.Г.Суменко. Англо-русский словарь по информационным технологиям. М.: ГП ЦНИИС, 2003.]

Тематики

• информационные технологии в целом

EN

• network

 

энергосистема
—
[А.С.Гольдберг. Англо-русский энергетический словарь. 2006 г.]

Тематики

• энергетика в целом

EN

• electric power system
• grid
• power grid
• network
• power network

3.48 сеть (network): Совокупность систем связи и систем обработки информации, которая может использоваться несколькими пользователями.

Источник: ГОСТ Р ИСО/ТО 13569-2007: Финансовые услуги. Рекомендации по информационной безопасности

3.48 сеть (network): Совокупность систем связи и систем обработки информации, которая может использоваться несколькими пользователями.

Источник: ГОСТ Р ИСО ТО 13569-2007: Финансовые услуги. Рекомендации по информационной безопасности