difference+engine

1) двигатель, мотор

2) ж.-д. локомотив

3) машина

4) процессор

- automatic-routing engine

- Analytical Engine

- Analytical Engine

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: Electronics and information technology

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George B.Grant was descended from families who came from Britain in the seventeenth century and was educated at the Bridgton (Maine) Academy, the Chandler Scientific School of Dartmouth College and the Lawrence Scientific School of Harvard College, where he graduated with the degree of BS in 1873. As an undergraduate he became interested in calculating machines, and his paper "On a new difference engine" was published in the American Journal of Science in August 1871. He also took out his first patents relating to calculating machines in 1872 and 1873. A machine of his design known as "Grant's Difference Engine" was exhibited at the Centennial Exposition in Philadelphia in 1876. Similar machines were also manufactured for sale; being sturdy and reliable, they did much to break down the prejudice against the use of calculating machines in business. Grant's work on calculating machines led to a requirement for accurate gears, so he established a machine shop for gear cutting at Charlestown, Massachusetts. He later moved the business to Boston and incorporated it under the name of Grant's Gear Works Inc., and continued to control it until his death. He also established two other gear-cutting shops, the Philadelphia Gear Works Inc., which he disposed of in 1911, and the Cleveland Gear Works Inc., which he also disposed of after a few years. Grant's commercial success was in connection with gear cutting and in this field he obtained several patents and contributed articles to the American Machinist. However, he continued to take an interest in calculating machines and in his later years carried out experimental work on their development.

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SUBJECT AREA: Electronics and information technology

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Charles Babbage was the son of a banker, Benjamin Babbage, and was a sickly child who had a rather haphazard education at private schools near Exeter and later at Enfield. Even as a child, he was inordinately fond of algebra, which he taught himself. He was conversant with several advanced mathematical texts, so by the time he entered Trinity College, Cambridge, in 1811, he was ahead of his tutors. In his third year he moved to Peterhouse, whence he graduated in 1814, taking his MA in 1817. He first contributed to the Philosophical Transactions of the Royal Society in 1815, and was elected a fellow of that body in 1816. He was one of the founders of the Astronomical Society in 1820 and served in high office in it.

While he was still at Cambridge, in 1812, he had the first idea of calculating numerical tables by machinery. This was his first difference engine, which worked on the principle of repeatedly adding a common difference. He built a small model of an engine working on this principle between 1820 and 1822, and in July of the latter year he read an enthusiastically received note about it to the Astronomical Society. The following year he was awarded the Society's first gold medal. He submitted details of his invention to Sir Humphry Davy, President of the Royal Society; the Society reported favourably and the Government became interested, and following a meeting with the Chancellor of the Exchequer Babbage was awarded a grant of £1,500. Work proceeded and was carried on for four years under the direction of Joseph Clement.

In 1827 Babbage went abroad for a year on medical advice. There he studied foreign workshops and factories, and in 1832 he published his observations in On the Economy of Machinery and Manufactures. While abroad, he received the news that he had been appointed Lucasian Professor of Mathematics at Cambridge University. He held the Chair until 1839, although he neither resided in College nor gave any lectures. For this he was paid between £80 and £90 a year! Differences arose between Babbage and Clement. Manufacture was moved from Clement's works in Lambeth, London, to new, fireproof buildings specially erected by the Government near Babbage's house in Dorset Square, London. Clement made a large claim for compensation and, when it was refused, withdrew his workers as well as all the special tools he had made up for the job. No work was possible for the next fifteen months, during which Babbage conceived the idea of his "analytical engine". He approached the Government with this, but it was not until eight years later, in 1842, that he received the reply that the expense was considered too great for further backing and that the Government was abandoning the project. This was in spite of the demonstration and perfectly satisfactory operation of a small section of the analytical engine at the International Exhibition of 1862. It is said that the demands made on manufacture in the production of his engines had an appreciable influence in improving the standard of machine tools, whilst similar benefits accrued from his development of a system of notation for the movements of machine elements. His opposition to street organ-grinders was a notable eccentricity; he estimated that a quarter of his mental effort was wasted by the effect of noise on his concentration.

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SUBJECT AREA: Mechanical, pneumatic and hydraulic engineering

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Although known as Clement in his professional life, his baptism at Asby and his death were registered under the name of Joseph Clemmet. He worked as a slater until the age of 23, but his interest in mechanics led him to spend much of his spare time in the local blacksmith's shop. By studying books on mechanics borrowed from his cousin, a watchmaker, he taught himself and with the aid of the village blacksmith made his own lathe. By 1805 he was able to give up the slating trade and find employment as a mechanic in a small factory at Kirkby Stephen. From there he moved to Carlisle for two years, and then to Glasgow where, while working as a turner, he took lessons in drawing; he had a natural talent and soon became an expert draughtsman. From about 1809 he was employed by Leys, Mason \& Co. of Aberdeen designing and making power looms. For this work he built a screw-cutting lathe and continued his self-education. At the end of 1813, having saved about £100, he made his way to London, where he soon found employment as a mechanic and draughtsman. Within a few months he was engaged by Joseph Bramah, and after a trial period a formal agreement dated 1 April 1814 was made by which Clement was to be Chief Draughtsman and Superintendent of Bramah's Pimlico works for five years. However, Bramah died in December 1814 and after his sons took over the business it was agreed that Clement should leave before the expiry of the five-year period. He soon found employment as Chief Draughtsman with Henry Maudslay \& Co. By 1817 Clement had saved about £500, which enabled him to establish his own business at Prospect Place, Newington Butts, as a mechanical draughtsman and manufacturer of high-class machinery. For this purpose he built lathes for his own use and invented various improvements in their detailed design. In 1827 he designed and built a facing lathe which incorporated an ingenious system of infinitely variable belt gearing. He had also built his own planing machine by 1820 and another, much larger one in 1825. In 1828 Clement began making fluted taps and dies and standardized the screw threads, thus anticipating on a small scale the national standards later established by Sir Joseph Whitworth. Because of his reputation for first-class workmanship, Clement was in the 1820s engaged by Charles Babbage to carry out the construction of his first Difference Engine.

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