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Heliograph (1)-2
A heliograph () is a solar telegraph system that signals by flashes of sunlight (generally using Morse code) reflected by a mirror. The flashes are produced by momentarily pivoting the mirror, or by interrupting the beam with a shutter. The heliograph was a simple but effective instrument for instantaneous optical communication over long distances during the late 19th and early 20th century. Its main uses were military, survey and forest protection work. Heliographs were standard issue in the British and Australian armies until the 1960s, and were used by the Pakistani army as late as 1975. Description There were many heliograph types. Most heliographs were variants of the British Army Mance Mark V version (Fig.1). It used a mirror with a small unsilvered spot in the centre. The sender aligned the heliograph to the target by looking at the reflected target in the mirror and moving their head until the target was hidden by the unsilvered spot. Keeping their head still, they then ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uncompahgre Peak
Uncompahgre Peak () is the List of mountain peaks of the Rocky Mountains#Highest prominent summits, sixth highest summit of the Rocky Mountains of North America and the U.S. state of Colorado. The Topographic prominence, prominent fourteener is the highest summit of the San Juan Mountains and the highest point in the drainage basin of the Colorado River#Watershed, Colorado River and the Gulf of California. It is located in the Uncompahgre Wilderness in the northern San Juans, in northern Hinsdale County, Colorado, Hinsdale County approximately 7 miles (11 km) west of the town of Lake City, Colorado, Lake City. Uncompahgre Peak has a broad summit plateau, rising about above the broad surrounding alpine basins. The south, east and west sides are not particularly steep, but the north face has a cliff. Like all peaks in the San Juan Mountains, Uncompahgre is of volcanic origin, but is not a volcano. The rock is of poor quality for climbing, precluding an ascent of the north ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Norris (1721–1786)
John Norris (1721 – 29 June 1786) was an English merchant and a member of the landed gentry. He was High Sheriff of Buckinghamshire in 1775. Biography Norris' father, Robert Norris (d. 1751) was a prosperous merchant in London, but through misfortune or mismanagement he lost all his money, and ended up in Fleet Prison (a debtor's prison). Fortunately his wife, Ellen Savage, came from a very wealthy family in Bishop's Tachbrook, Warwickshire, and when her father died she inherited property and lands worth £140,000. The young Norris was educated at Eton College, and when he was 17 he matriculated at Christ Church, Oxford. He was offered a demyship at Magdalen College, Oxford, from where he gained BA and MA degrees. He later obtained a Doctor of Civil Law. On his father's death, John Norris inherited land and property in Warwickshire, Hampshire, Buckinghamshire and in Islington. He had two manors, Hawley Place in Hawley, Hampshire and Hughenden Manor in High Wycombe, Buck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herodotus
Herodotus ( ; grc, , }; BC) was an ancient Greek historian and geographer from the Greek city of Halicarnassus, part of the Persian Empire (now Bodrum, Turkey) and a later citizen of Thurii in modern Calabria ( Italy). He is known for having written the '' Histories'' – a detailed account of the Greco-Persian Wars. Herodotus was the first writer to perform systematic investigation of historical events. He is referred to as " The Father of History", a title conferred on him by the ancient Roman orator Cicero. The ''Histories'' primarily cover the lives of prominent kings and famous battles such as Marathon, Thermopylae, Artemisium, Salamis, Plataea, and Mycale. His work deviates from the main topics to provide a cultural, ethnographical, geographical, and historiographical background that forms an essential part of the narrative and provides readers with a wellspring of additional information. Herodotus has been criticized for his inclusion of "legends and f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Marathon
The Battle of Marathon took place in 490 BC during the first Persian invasion of Greece. It was fought between the citizens of Athens, aided by Plataea, and a Persian force commanded by Datis and Artaphernes. The battle was the culmination of the first attempt by Persia, under King Darius I, to subjugate Greece. The Greek army inflicted a crushing defeat on the more numerous Persians, marking a turning point in the Greco-Persian Wars. The first Persian invasion was a response to Athenian involvement in the Ionian Revolt, when Athens and Eretria sent a force to support the cities of Ionia in their attempt to overthrow Persian rule. The Athenians and Eretrians had succeeded in capturing and burning Sardis, but they were then forced to retreat with heavy losses. In response to this raid, Darius swore to burn down Athens and Eretria. According to Herodotus, Darius had his bow brought to him and then shot an arrow "upwards towards heaven", saying as he did so: "Zeus, that it may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capri
Capri ( , ; ; ) is an island located in the Tyrrhenian Sea off the Sorrento Peninsula, on the south side of the Gulf of Naples in the Campania region of Italy. The main town of Capri that is located on the island shares the name. It has been a resort since the time of the Roman Republic. Some of the main features of the island include the (the little harbour), the Belvedere of Tragara (a high panoramic promenade lined with villas), the limestone crags called sea stacks that project above the sea (the ), the town of Anacapri, the Blue Grotto (), the ruins of the Imperial Roman villas, and the vistas of various towns surrounding the Island of Capri including Positano, Amalfi, Ravello, Sorrento, Nerano, and Naples. Capri is part of the region of Campania, Metropolitan City of Naples. The town of Capri is a and the island's main population centre. The island has two harbours, and (the main port of the island). The separate of Anacapri is located high on the hills to the w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiberius
Tiberius Julius Caesar Augustus (; 16 November 42 BC – 16 March AD 37) was the second Roman emperor. He reigned from AD 14 until 37, succeeding his stepfather, the first Roman emperor Augustus. Tiberius was born in Rome in 42 BC. His father was the politician Tiberius Claudius Nero and his mother was Livia Drusilla, who would eventually divorce his father, and marry the future-emperor Augustus in 38 BC. Following the untimely deaths of Augustus' two grandsons and adopted heirs, Gaius and Lucius Caesar, Tiberius was designated Augustus' successor. Prior to this, Tiberius had proved himself an able diplomat, and one of the most successful Roman generals: his conquests of Pannonia, Dalmatia, Raetia, and (temporarily) parts of Germania laid the foundations for the empire's northern frontier. Early in his career, Tiberius was happily married to Vipsania, daughter of Augustus' friend, distinguished general and intended heir, Marcus Vipsanius Agrippa. They had a son, Drusus Jul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Telegraphy
An optical telegraph is a line of stations, typically towers, for the purpose of conveying textual information by means of visual signals. There are two main types of such systems; the semaphore telegraph which uses pivoted indicator arms and conveys information according to the direction the indicators point, and the shutter telegraph which uses panels that can be rotated to block or pass the light from the sky behind to convey information. The most widely used system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth centuries. This system is often referred to as ''semaphore'' without qualification. Lines of relay towers with a semaphore rig at the top were built within line of sight of each other, at separations of . Operators at each tower would watch the neighboring tower through a telescope, and when the semaphore arms began to move spelling out a message, they would pass the message on to the next tower. This sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geodetic Survey
Geodesy ( ) is the Earth science of accurately measuring and understanding Earth's figure ( geometric shape and size), orientation in space, and gravity. The field also incorporates studies of how these properties change over time and equivalent measurements for other planets (known as ''planetary geodesy''). Geodynamical phenomena, including crustal motion, tides and polar motion, can be studied by designing global and national control networks, applying space geodesy and terrestrial geodetic techniques and relying on datums and coordinate systems. The job title is geodesist or geodetic surveyor. History Definition The word geodesy comes from the Ancient Greek word ''geodaisia'' (literally, "division of Earth"). It is primarily concerned with positioning within the temporally varying gravitational field. Geodesy in the German-speaking world is divided into "higher geodesy" ( or ), which is concerned with measuring Earth on the global scale, and "practical geodes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliotrope (instrument)
The heliotrope is an instrument that uses a mirror to reflect sunlight over great distances to mark the positions of participants in a land survey. The heliotrope was invented in 1821 by the German mathematician Carl Friedrich Gauss. The word "heliotrope" is taken from the Greek: ''helios'' (), meaning "sun", and '' tropos'' (), meaning "turn". Heliotropes were used in surveys from Gauss's survey in Germany in 1821 through the late 1980s, when GPS measurements replaced the use of the heliotrope in long distance surveys. Colonel Sir George Everest introduced the use of heliotropes into the Great Trigonometric Survey in India around 1831, and the US Coast and Geographic Survey used heliotropes to survey the United States. ThIndian specification for heliotropeswas updated in 1981, and the American military specification for heliotropes (MIL-H-20194E) was retired on 8 December 1995. Surveyors used the heliotrope as a specialized form of survey target; it was employed during large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Göttingen
The University of Göttingen, officially the Georg August University of Göttingen, (german: Georg-August-Universität Göttingen, known informally as Georgia Augusta) is a public research university in the city of Göttingen, Germany. Founded in 1734 by George II, King of Great Britain and Elector of Hanover, and starting classes in 1737, the Georgia Augusta was conceived to promote the ideals of the Enlightenment. It is the oldest university in the state of Lower Saxony and the largest in student enrollment, which stands at around 31,600. Home to many noted figures, it represents one of Germany's historic and traditional institutions. According to an official exhibition held by the University of Göttingen in 2002, 44 Nobel Prize winners had been affiliated with the University of Göttingen as alumni, faculty members or researchers by that year alone. The University of Göttingen was previously supported by the German Universities Excellence Initiative, holds memberships ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Friedrich Gauss
Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes referred to as the ''Princeps mathematicorum'' () and "the greatest mathematician since antiquity", Gauss had an exceptional influence in many fields of mathematics and science, and he is ranked among history's most influential mathematicians. Also available at Retrieved 23 February 2014. Comprehensive biographical article. Biography Early years Johann Carl Friedrich Gauss was born on 30 April 1777 in Brunswick (Braunschweig), in the Duchy of Brunswick-Wolfenbüttel (now part of Lower Saxony, Germany), to poor, working-class parents. His mother was illiterate and never recorded the date of his birth, remembering only that he had been born on a Wednesday, eight days before the Feast of the Ascension (which occurs 39 days after Easter). Ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
