Neuchâtel

Neuchâtel ⇒ Towns and cities, Swiss cantons pr n Neuchâtel ; the canton of Neuchâtel le canton de Neuchâtel.

1) Общая лексика: Нёвшатель (название кантона в Швейцарии), Ньюшатель (название кантона в Швейцарии)

2) География: (г.) Невшатель (Швейцария)

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SUBJECT AREA: Horology

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When Breguet was 11 years old his father died and his mother married a Swiss watchmaker who had Paris connections. His stepfather introduced him to horology and this led to an apprenticeship in Paris, during which he also attended evening classes in mathematics at the Collège Mazarin. In 1775 he married and set up a workshop in Paris, initially in collaboration with Xavier Gide. There he established a reputation among the aristocracy for elegant and innovative timepieces which included a perpétuelle, or self-winding watch, which he developed from the ideas of Perrelet. He also enjoyed the patronage of Marie Antoinette and Louis XVI. During the French Revolution his life was in danger and in 1793 he fled to Neuchâtel. The two years he spent there comprised what was intellectually one of his most productive periods and provided many of the ideas that he was able to exploit after he had returned to Paris in 1795. By the time of his death he had become the most prestigious watchmaker in Europe: he supplied timepieces to Napoleon and, after the fall of the Empire, to Louis XVIII, as well as to most of the crowned heads of Europe.

Breguet divided his contributions to horology into three categories: improvements in appearance and functionality; improvements in durability; and improvements in timekeeping. His pendule sympathique was in the first category and consisted of a clock which during the night set a watch to time, regulated it and wound it. His parachute, a spring-loaded bearing, made a significant contribution to the durability of a watch by preventing damage to its movement if it was dropped. Among the many improvements that Breguet made to timekeeping, two important ones were the introduction of the overcoil balance spring and the tourbillon. By bending the outside end of the balance spring over the top of the coils Breguet was able to make the oscillations of the balance isochronous, thus achieving for the flat spring what Arnold had already accomplished for the cylindrical balance spring. The timekeeping of a balance is also dependent on its position, and the tourbillon was an attempt to average-out positional errors by placing the balance wheel and the escapement in a cage that rotated once every minute. This principle was revived in a simplified form in the karussel at the end of the nineteenth century.

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SUBJECT AREA: Photography, film and optics

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Guinand received little formal education and followed his father's trade of joiner. He specialized in making clock cases, but after learning how to cast metals he took up the more lucrative work of making watch cases. When he was about 20 years old, in a customer's house he caught sight of an English telescope, a rarity in a Swiss mountain village. Intrigued, he obtained permission to examine it. This aroused his interest in optical matters and he began making spectacles and small telescopes.

Achromatic lenses were becoming known, their use being to remove the defect of chromatic aberration or coloured optical images, but there remained defects due to imperfections in the glass itself. Stimulated by offers of prizes by scientific bodies, including the Royal Society of London, for removing these defects, Guinand set out to remedy them. He embarked in 1784 on a long and arduous series of experiments, varying the materials and techniques for making glass. The even more lucrative trade of making bells for repeaters provided the funds for a furnace capable of holding 2 cwt (102 kg) of molten glass. By 1798 or so he had succeeded in making discs of homogeneous glass. He impressed the famous Parisian astronomer de Lalande with them and his glass became well enough known for scientists to visit him. In 1805 Fraunhofer persuaded Guinand to join his optical-instrument works at Benediktheurn, in Bavaria, to make lenses. After nine years, Guinand returned to Brenets with a pension, on condition he made no more glass and disclosed no details of his methods. After two years these conditions had become irksome and he relinquished the pension. On 19 February 1823 Guinand described his discoveries in his classic "Memoir on the making of optical glass, more particularly of glass of high refractive index for use in the production of achromatic lenses", presented to the Société de Physique et d'Histoire Naturelle de Genève. This gives details of his experiments and investigations and discusses a suitable pot-clay stirrer and stirring mechanism for the molten glass, with temperature control, to overcome optical-glass defects such as bubbles, seeds, cords and colours. Guinand was hailed as the man in Europe who had achieved this and has thus rightly been called the founder of the era of optical glassmaking.

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SUBJECT AREA: Electronics and information technology, Horology

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After serving an apprenticeship with a clock-maker in Blaubeuren, Hipp worked for various clockmakers before setting up his own workshop in Reutlingen in 1840. In 1842 he made his first electric clock with an ingenious toggle mechanism for switching the current, although he claimed that the idea had occurred to him eight years earlier. The switching mechanism was the Achilles' heel of early electric clocks. It was usually operated by the pendulum and it presented the designer with a dilemma: if the switch made a firm contact it adversely affected the timekeeping, but if the contact was lightened it sometimes failed to operate due to dirt or corrosion on the contacts. The Hipp toggle switch overcame this problem by operating only when the amplitude of the pendulum dropped below a certain value. As this occurred infrequently, the contact pressure could be increased to provide reliable switching without adversely affecting the timekeeping. It is an indication of the effectiveness of the Hipp toggle that it was used in clocks for over one hundred years and was adopted by many other makers in addition to Hipp and his successor Favag. It was generally preferred for its reliability rather than its precision, although a regulator made in 1881 for the observatory at Neuchâtel performed creditably. This regulator was enclosed in an airtight case at low pressure, eliminating errors due to changes in barometric pressure. This practice later became standard for observatory regulators such as those of Riefler and Shortt. The ability of the Hipp toggle to provide more power when the clock was subjected to an increased load made it particularly suitable for use in turret clocks, whose hands were exposed to the vagaries of the weather. Hipp also improved the operation of slave dials, which were advanced periodically by an electrical impulse from a master clock. If the electrical contacts "chattered" and produced several impulses instead of a single sharp impulse, the slave dials would not indicate the correct time. Hipp solved this problem by producing master clocks which delivered impulses that alternated in polarity, and slave dials which only advanced when the polarity was changed in this way. Polarized impulses delivered every minute became the standard practice for slave dials used on the European continent. Hipp also improved Wheatstone's chronoscope, an instrument that was used for measuring very short intervals of time (such as those involved in ballistics).

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queso Neuchatel.

SUBJECT AREA: Horology, Metallurgy

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Guillaume came from a family of clock-and watchmakers. He was educated at the Gymnasium in Neuchâtel and at Zurich Polytechnic, from which he received his doctorate in 1883 for a thesis on electrolytic capacitors. In the same year he joined the International Bureau of Weights and Measures at Sèvres in France, where he was to spend the rest of his working life. He retired as Director in 1936. At the bureau he was involved in distributing the national standards of the metre to countries subscribing to the General Conference on Weights and Measures that had been held in 1889. This made him aware of the crucial effect of thermal expansion on the lengths of the standards and he was prompted to look for alternative materials that would be less costly than the platinum alloys which had been used. While studying nickel steels he made the surprising discovery that the thermal expansion of certain alloy compositions was less than that of the constituent metals. This led to the development of a steel containing about 36 per cent nickel that had a very low thermal coefficient of expansion. This alloy was subsequently named "invar", an abbreviation of invariable. It was well known that changes in temperature affected the timekeeping of clocks by altering the length of the pendulum, and various attempts had been made to overcome this defect, most notably the mercury-compensated pendulum of Graham and the gridiron pendulum of Harrison. However, an invar pendulum offered a simpler and more effective method of temperature compensation and was used almost exclusively for pendulum clocks of the highest precision.

Changes in temperature can also affect the timekeeping of watches and chronometers, but this is due mainly to changes in the elasticity or stiffness of the balance spring rather than to changes in the size of the balance itself. To compensate for this effect Guillaume developed another more complex nickel alloy, "elinvar" (elasticity invariable), whose elasticity remained almost constant with changes in temperature. This had two practical consequences: the construction of watches could be simplified (by using monometallic balances) and more accurate chronometers could be made.

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See also: Le Roy, Pierre

SUBJECT AREA: Electronics and information technology, Horology

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Hetzel trained as an electrical engineer at the Federal Polytechnic in Zurich and worked for several years in the field of telecommunications before joining the Bulova Watch Company in 1950. At that time several companies were developing watches with electromagnetically maintained balances, but they represented very little advance on the mechanical watch and the mechanical switching mechanism was unreliable. In 1952 Hetzel started work on a much more radical design which was influenced by a transistorized tuning-fork oscillator that he had developed when he was working on telecommunications. Tuning forks, whose vibrations were maintained electromagnetically, had been used by scientists during the nineteenth century to measure small intervals of time, but Niaudet- Breguet appears to have been the first to use a tuning fork to control a clock. In 1866 he described a mechanically operated tuning-fork clock manufactured by the firm of Breguet, but it was not successful, possibly because the fork did not compensate for changes in temperature. The tuning fork only became a precision instrument during the 1920s, when elinvar forks were maintained in vibration by thermionic valve circuits. Their primary purpose was to act as frequency standards, but they might have been developed into precision clocks had not the quartz clock made its appearance very shortly afterwards. Hetzel's design was effectively a miniaturized version of these precision devices, with a transistor replacing the thermionic valve. The fork vibrated at a frequency of 360 cycles per second, and the hands were driven mechanically from the end of one of the tines. A prototype was working by 1954, and the watch went into production in 1960. It was sold under the tradename Accutron, with a guaranteed accuracy of one minute per month: this was a considerable improvement on the performance of the mechanical watch. However, the events of the 1920s were to repeat themselves, and by the end of the decade the Accutron was eclipsed by the introduction of quartz-crystal watches.

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SUBJECT AREA: Mechanical, pneumatic and hydraulic engineering

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Hans Renold was educated at the cantonal school of his native town and at the Polytechnic in Zurich. He worked in two or three small workshops during the polytechnic vacations and served an apprenticeship of eighteen months in an engineering works at Neuchâtel, Switzerland. After a short period of military service he found employment as a draughtsman in an engineering firm at Saint-Denis, near Paris, from 1871 to 1873. In 1873 Renold moved first to London and then to Manchester as a draughtsman and inspector with a firm of machinery exporters. From 1877 to 1879 he was a partner in his own firm of machine exporters. In 1879 he purchased a small firm in Salford making chain for the textile industry. At about this time J.K.Starley introduced the "safety" bicycle, which, however, lacked a satisfactory drive chain. Renold met this need with the invention of the bush roller chain, which he patented in 1880. The new chain formed the basis of the precision chain industry: the business expanded and new premises were acquired in Brook Street, Manchester, in 1881. In the same year Renold became a naturalized British subject.

Continued expansion of the business necessitated the opening of a new factory in Brook Street in 1889. The factory was extended in 1895, but by 1906 more accommodation was needed and a site of 11 ½ acres was acquired in the Manchester suburb of Burnage: the move to the new building was finally completed in 1914. Over the years, further developments in the techniques of chain manufacture were made, including the invention in 1895 of the inverted tooth or silent chain. Renold made his first visit to America in 1891 to study machine-tool developments and designed for his own works special machine tools, including centreless grinding machines for dealing with wire rods up to 10 ft (3 m) in length.

The business was established as a private limited company in 1903 and merged with the Coventry Chain Company Ltd in 1930. Good industrial relations were always of concern to Renold and he established a 48-hour week as early as 1896, in which year a works canteen was opened. Joint consultation with shop stewards date2 from 1917. Renold was elected a Member of the Institution of Mechanical Engineers in 1902 and in 1917 he was made a magistrate of the City of Manchester.

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