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Foy–Breguet Telegraph
The Foy–Breguet telegraph, also called the French telegraph, was an electrical telegraph of the needle telegraph type developed by Louis-François-Clement Breguet and Alphonse Foy in the 1840s for use in France. The system used two-needle instruments that presented a display using the same code as that on the optical telegraph of Claude Chappe. The Chappe telegraph was extensively used in France by the government, so this arrangement was appealing to them as it meant there was no need to retrain operators. Most needle telegraph systems moved the needles by means of an electromagnet driven by battery power applied to the line at the sending end. In contrast, the Foy-Breguet telegraph used electromagnets but they did not directly drive the needle. Instead, they operated the detent of a clockwork mechanism which released the needle to move on one position at a time. The Chappe telegraph existed in some other countries, but no country besides France tried to duplicate the Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooke And Wheatstone Telegraph
The Cooke and Wheatstone telegraph was an early electrical telegraph system dating from the 1830s invented by English inventor William Fothergill Cooke and English scientist Charles Wheatstone. It was a form of needle telegraph, and the first telegraph system to be put into commercial service. The receiver consisted of a number of needles which could be moved by electromagnetic coils to point to letters on a board. This feature was liked by early users who were unwilling to learn codes, and employers who did not want to invest in staff training. In later systems the letter board was dispensed with, and the code was read directly from the movement of the needles. This came about because the number of needles was reduced, leading to more complex codes. The change was motivated by the economic need to reduce the number of telegraph wires used, which was related to the number of needles. The change became more urgent as the insulation of some of the early installations deteriorat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backward Compatibility
Backward compatibility (sometimes known as backwards compatibility) is a property of an operating system, product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system, especially in telecommunications and computing. Modifying a system in a way that does not allow backward compatibility is sometimes called " breaking" backward compatibility. A complementary concept is forward compatibility. A design that is forward-compatible usually has a roadmap for compatibility with future standards and products. A related term from programming jargon is hysterical reasons or hysterical raisins (near-homophones for "historical reasons"), as the purpose of some software features may be solely to support older hardware or software versions. Usage In hardware A simple example of both backward and forward compatibility is the introduction of FM radio in stereo. FM radio was initially mono, with only one audio channel represented ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abraham Niclas Edelcrantz
Abraham Niclas (Clewberg) Edelcrantz (28 July 1754 – 15 March 1821) was a Finnish born Swedish poet and inventor. He was a member of the Swedish Academy, chair 2, from 1786 to 1821. Edelcrantz was the librarian at The Royal Academy of Turku. In 1783 he moved to Stockholm to lead the Royal Theater and later work as the private secretary of the king Gustaf III. He is known for his experiment with the optical telegraph. He inaugurated his telegraph with a poem dedicated to the Swedish King on his birthday in 1794. The message went from the Palace in Stockholm to the King a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Napoleon
Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader who rose to prominence during the French Revolution and led successful campaigns during the Revolutionary Wars. He was the ''de facto'' leader of the French Republic as First Consul from 1799 to 1804, then Emperor of the French from 1804 until 1814 and again in 1815. Napoleon's political and cultural legacy endures to this day, as a highly celebrated and controversial leader. He initiated many liberal reforms that have persisted in society, and is considered one of the greatest military commanders in history. His wars and campaigns are studied by militaries all over the world. Between three and six million civilians and soldiers perished in what became known as the Napoleonic Wars. Napoleon was born on the island of Corsica, not long af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia and it is located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. Comprising the westernmost peninsulas of Eurasia, it shares the continental landmass of Afro-Eurasia with both Africa and Asia. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south and Asia to the east. Europe is commonly considered to be Boundaries between the continents of Earth#Asia and Europe, separated from Asia by the drainage divide, watershed of the Ural Mountains, the Ural (river), Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea and the waterways of the Turkish Straits. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Codepoint
In character encoding terminology, a code point, codepoint or code position is a numerical value that maps to a specific character. Code points usually represent a single grapheme—usually a letter, digit, punctuation mark, or whitespace—but sometimes represent symbols, control characters, or formatting. The set of all possible code points within a given encoding/character set make up that encoding's ''codespace''. For example, the character encoding scheme ASCII comprises 128 code points in the range 0 hex to 7Fhex, Extended ASCII comprises 256 code points in the range 0hex to FFhex, and Unicode comprises code points in the range 0hex to 10FFFFhex. The Unicode code space is divided into seventeen planes (the basic multilingual plane, and 16 supplementary planes), each with (= 216) code points. Thus the total size of the Unicode code space is 17 × = . Definition The notion of a code point is used for abstraction, to distinguish both: * the numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Codebook
A codebook is a type of document used for gathering and storing cryptography codes. Originally codebooks were often literally , but today codebook is a byword for the complete record of a series of codes, regardless of physical format. Cryptography In cryptography, a codebook is a document used for implementing a code. A codebook contains a lookup table for coding and decoding; each word or phrase has one or more strings which replace it. To decipher messages written in code, corresponding copies of the codebook must be available at either end. The distribution and physical security of codebooks presents a special difficulty in the use of codes, compared to the secret information used in ciphers, the key, which is typically much shorter. The United States National Security Agency documents sometimes use ''codebook'' to refer to block ciphers; compare their use of ''combiner-type algorithm'' to refer to stream ciphers. Codebook come in two forms, one-part or two-part: * In one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watchmaker
A watchmaker is an artisan who makes and repairs watches. Since a majority of watches are now factory-made, most modern watchmakers only repair watches. However, originally they were master craftsmen who built watches, including all their parts, by hand. Modern watchmakers, when required to repair older watches, for which replacement parts may not be available, must have fabrication skills, and can typically manufacture replacements for many of the parts found in a watch. The term clockmaker refers to an equivalent occupation specializing in clocks. Most practising professional watchmakers service current or recent production watches. They seldom fabricate replacement parts. Instead they obtain and fit factory spare parts applicable to the watch brand being serviced. The majority of modern watchmakers, particularly in Switzerland and other countries in Europe, work directly for the watchmaking industry and may have completed a formal watchmaking degree at a technical school. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abraham-Louis Breguet
Abraham-Louis Breguet (10 January 1747 – 17 September 1823), born in Neuchâtel, then a Prussian principality, was a horologist who made many innovations in the course of a career in watchmaking industry. He was the founder of the Breguet company, which is now the luxury watch division of the Swiss Swatch Group. In his lifetime he was considered the leading watchmaker of his day, and he built up a clientele that included many leading public figures and members of the European nobility. Alongside his friend and contemporary John Arnold, Breguet is now widely acknowledged as one of the greatest horologists of all time. One of his famous ancestors was Jean Breguet (who died in 1593) a Protestant pastor in Neuchâtel very much influenced by the ideas of John Calvin. Life Breguet was born in Neuchâtel to Jonas-Louis Breguet and Suzanne-Marguerite Bolle. Breguet's father died in 1758 when he was ten, and his formal schooling ended when he was 12. Breguet's mother remarri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Point
In character encoding terminology, a code point, codepoint or code position is a numerical value that maps to a specific character. Code points usually represent a single grapheme—usually a letter, digit, punctuation mark, or whitespace—but sometimes represent symbols, control characters, or formatting. The set of all possible code points within a given encoding/character set make up that encoding's ''codespace''. For example, the character encoding scheme ASCII comprises 128 code points in the range 0 hex to 7Fhex, Extended ASCII comprises 256 code points in the range 0hex to FFhex, and Unicode comprises code points in the range 0hex to 10FFFFhex. The Unicode code space is divided into seventeen planes (the basic multilingual plane, and 16 supplementary planes), each with (= 216) code points. Thus the total size of the Unicode code space is 17 × = . Definition The notion of a code point is used for abstraction, to distinguish both: * the num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rouen
Rouen (, ; or ) is a city on the River Seine in northern France. It is the prefecture of the Regions of France, region of Normandy (administrative region), Normandy and the Departments of France, department of Seine-Maritime. Formerly one of the largest and most prosperous cities of Middle Ages, medieval Europe, the population of the metropolitan area (french: functional area (France), aire d'attraction) is 702,945 (2018). People from Rouen are known as ''Rouennais''. Rouen was the seat of the Exchequer of Normandy during the Middle Ages. It was one of the capitals of the Anglo-Normans, Anglo-Norman dynasties, which ruled both England and large parts of modern France from the 11th to the 15th centuries. From the 13th century onwards, the city experienced a remarkable economic boom, thanks in particular to the development of textile factories and river trade. Claimed by both the French and the English during the Hundred Years' War, it was on its soil that Joan of Arc was tried ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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