"temperature scale to be widely used). In other words, Fahrenheit's inventions ushered in the first revolution in the history of thermometry (branch of physics concerned with methods of temperature measurement). From the early 1710s until the beginnings of the electronic era, mercury-in-glass thermometers were among the most reliable and accurate thermometers ever invented. Fahrenheit was born in the city of Danzig (Gdańsk), Pomeranian Voivodeship in the Polish–Lithuanian Commonwealth, but lived most of his life in the Dutch Republic. The Fahrenheits were a German Hanse merchant family who had lived in several Hanseatic cities. Fahrenheit's great-grandfather had lived in Rostock, and"
"(1611-1687) created the first world's great astronomical observatory equipped with telescopes. Hevelius was also a physicist because he discovered centuries old changes in magnetic declination. He was technician too, because he constructed Poland's first pendulum clock, conceived, designed and built the first world's periscope, as well as the first micrometer screw which belongs today to the Gdańsk City Council. Daniel Gabriel Fahrenheit (1686-1736) was born in Gdańsk. He is mainly known for being the first to use mercury in temperature measuring devices (previously alcohol was used) and developed his own scale of 0 to 212 degrees. Hevelius and Fahrenheit, the"
"a physicist, engineer, inventor and the creator of a mercury thermometer temperature scale. There are two portraits of the great physicist. The first can be found in a window niche. The other is covered with a thick glass pane. Its upper section looks like a network of blood vessels, while the blue-tinted section at the bottom shows crystal-like structures that can often be seen on glass when temperature is lower than 0°C or 32°F. In the middle there is an image of a Fahrenheit thermometer. While the university buildings were being completed in 1904 the mains gas supply was installed"
"Galileo thermometer A Galileo thermometer (or Galilean thermometer) is a thermometer made of a sealed glass cylinder containing a clear liquid and several glass vessels of varying density. As the temperature changes, the individual floats rise or fall in proportion to their respective density and the density of the surrounding liquid. It is named after Galileo Galilei because he discovered the principle on which this thermometer is based—that the density of a liquid changes in proportion to its temperature. Although named after the 16th–17th-century physicist Galileo, the thermometer described in this article was not invented by him. Galileo did invent"
"Fahrenheit The Fahrenheit scale is a temperature scale based on one proposed in 1724 by Dutch–German–Polish physicist Daniel Gabriel Fahrenheit (1686–1736). It uses the degree Fahrenheit (symbol: °F) as the unit. Several accounts of how he originally defined his scale exist. The lower defining point, 0 °F, was established as the temperature of a solution of brine made from equal parts of ice, water and salt (ammonium chloride). Further limits were established as the melting point of ice (32 °F) and his best estimate of the average human body temperature (96 °F, about 2.6 °F less than the modern value"
"character: ""The sequence + is preferred over , and those two sequences should be treated as identical for searching."" Fahrenheit The Fahrenheit scale is a temperature scale based on one proposed in 1724 by Dutch–German–Polish physicist Daniel Gabriel Fahrenheit (1686–1736). It uses the degree Fahrenheit (symbol: °F) as the unit. Several accounts of how he originally defined his scale exist. The lower defining point, 0 °F, was established as the temperature of a solution of brine made from equal parts of ice, water and salt (ammonium chloride). Further limits were established as the melting point of ice (32 °F) and"
"temperature. He followed Ferdinand II of Tuscany's idea of enclosing a liquid in a sealed glass tube which made it immune to pressure changes. Rømer's thermometer was also an improvement in the fluid that he used. He used a mixture of alcohol and water, conveniently available in the form of wine. This avoided the drawbacks of both the low boiling point of pure alcohol and the extreme non-linearity of pure water near freezing. Daniel Gabriel Fahrenheit, inventor of the Fahrenheit scale, learned of Rømer's work and visited him in 1708. Fahrenheit described how he borrowed the idea for his scale"
"of Linnaeus thermometers, Daniel Ekström. The Delisle thermometer remained in use for almost 100 years in Russia. One of its users was Mikhail Lomonosov, who reversed it, as Jean-Pierre Christin did with Celsius' scale, making the freezing point of water 0 °D and the boiling point 150 °D. Delisle scale The Delisle scale (°D) is a temperature scale invented in 1732 by the French astronomer Joseph-Nicolas Delisle (1688–1768). Delisle was the author of ""Mémoires pour servir à l'histoire et aux progrès de l'Astronomie, de la Géographie et de la Physique"" (1738). In 1732, Delisle built a thermometer that used mercury"
"also to confounding with atmospheric pressure changes. These early devices were called thermoscopes. The first sealed thermometer was constructed in 1641 by the Grand Duke of Toscani, Ferdinand II. The development of today's thermometers and temperature scales began in the early 18th century, when Gabriel Fahrenheit produced a mercury thermometer and scale, both developed by Ole Christensen Rømer. Fahrenheit's scale is still in use, alongside the Celsius and Kelvin scales. Many methods have been developed for measuring temperature. Most of these rely on measuring some physical property of a working material that varies with temperature. One of the most common"
"that used this scale. In 1744, coincident with the death of Anders Celsius, the Swedish botanist Carl Linnaeus (1707–1778) reversed Celsius's scale. His custom-made ""linnaeus-thermometer"", for use in his greenhouses, was made by Daniel Ekström, Sweden's leading maker of scientific instruments at the time, whose workshop was located in the basement of the Stockholm observatory. As often happened in this age before modern communications, numerous physicists, scientists, and instrument makers are credited with having independently developed this same scale; among them were Pehr Elvius, the secretary of the Royal Swedish Academy of Sciences (which had an instrument workshop) and with"
"by observing that on a very hot day, he stayed cooler in a wet shirt in a breeze than he did in a dry one. To understand this phenomenon more clearly Franklin conducted experiments. In 1758 on a warm day in Cambridge, England, Franklin and fellow scientist John Hadley experimented by continually wetting the ball of a mercury thermometer with ether and using bellows to evaporate the ether. With each subsequent evaporation, the thermometer read a lower temperature, eventually reaching . Another thermometer showed that the room temperature was constant at . In his letter ""Cooling by Evaporation"", Franklin noted"
"sometimes called perpetuum mobile. Galileo's own work with the thermoscope led him to develop an essentially atomistic conception of heat, published in his book ""Il Saggiatore"" in 1623. It is thought, but not certain that Galileo Galilei discovered the specific principle on which the device is based and built the first thermoscope in 1593. Galileo mentioned to his friend Cesare Marsili that he invented a thermoscope as far back as 1606. The inventor could be his physician friend Santorio Santorio or another person of the learned circle in Venice of which they were members. What is certain is that the"
"things as rainfall, runoff, drainage area, velocity, river cross-section measurements and discharge. Advances in the 18th century included Daniel Bernoulli's piezometer and Bernoulli's equation as well as the Pitot tube by Henri Pitot. In the 19th century, groundwater hydrology was furthered by Darcy's law, the Dupuit-Thiem well formula, and the Hagen-Poiseuille equation for flows through pipes. ""Physical Geography of the Sea"", the first textbook of oceanography, was written by Matthew Fontaine Maury in 1855. The thermoscope, or Galileo thermometer, was constructed by Galileo Galilei in 1607. In 1643, Evangelista Torricelli invented the mercury barometer. Blaise Pascal (in 1648) rediscovered that"
"either glass or metal. The Nicholson hydrometer is similar in design, but instead of a weighted bulb at the bottom there is a small container (""basket"") into which a sample can be placed. Fahrenheit hydrometer The Fahrenheit hydrometer is a device used to measure the density of a liquid. It was invented by Daniel Gabriel Fahrenheit (1686–1736), better known for his work in thermometry. The Fahrenheit hydrometer is a constant-volume device that will float in water. In the figure shown here, the hydrometer is floating vertically in a cylinder containing a liquid. At the bottom of the hydrometer is a"
"Medical thermometer A medical thermometer (also called clinical thermometer) is used for measuring human or animal body temperature. The tip of the thermometer is inserted into the mouth under the tongue (""oral"" or ""sub-lingual temperature""), under the armpit (""axillary temperature""), or into the rectum via the anus (""rectal temperature""). The medical thermometer began as an instrument more appropriately called a water thermoscope, constructed by Galileo Galilei circa 1592–1593. It lacked an accurate scale with which to measure temperature and could be affected by changes in atmospheric pressure. Italian physician Santorio Santorio is the first known individual to have put a"
"temperature variations. Electronic thermostats have an electronic equivalent. Early technologies included mercury thermometers with electrodes inserted directly through the glass, so that when a certain (fixed) temperature was reached the contacts would be closed by the mercury. These were accurate to within a degree of temperature. Common sensor technologies in use today include: These may then control the heating or cooling apparatus using: Possibly the earliest recorded examples of thermostat control were built by the Dutch innovator Cornelis Drebbel (1572–1633) around 1620 in England. He invented a mercury thermostat to regulate the temperature of a chicken incubator. This is one"
"one degree Celsius) requires 4186 joules per kilogram (J/kg). Temperature measurement using modern scientific thermometers and temperature scales goes back at least as far as the early 18th century, when Gabriel Fahrenheit adapted a thermometer (switching to mercury) and a scale both developed by Ole Christensen Rømer. Fahrenheit's scale is still in use in the United States for non-scientific applications. Temperature is measured with thermometers that may be calibrated to a variety of temperature scales. In most of the world (except for Belize, Myanmar, Liberia and the United States), the Celsius scale is used for most temperature measuring purposes. Most"
"Daniell cell The Daniell cell is a type of electrochemical cell invented in 1836 by John Frederic Daniell, a British chemist and meteorologist, and consisted of a copper pot filled with a copper (II) sulfate solution, in which was immersed an unglazed earthenware container filled with sulfuric acid and a zinc electrode. He was searching for a way to eliminate the hydrogen bubble problem found in the voltaic pile, and his solution was to use a second electrolyte to consume the hydrogen produced by the first. Zinc sulfate may be substituted for the sulfuric acid. The Daniell cell was a"
"John Frederic Daniell John Frederic Daniell FRS (12 March 1790 – 13 March 1845) was an English chemist and physicist. Daniell was born in London. In 1831 he became the first professor of chemistry at the newly founded King's College London; and in 1835 he was appointed to the equivalent post at the East India Company's Military Seminary at Addiscombe, Surrey. His name is best known for his invention of the Daniell cell, an element of an electric battery much better than voltaic cells. He also invented the dew-point hygrometer known by his name, and a register pyrometer; and in"
"circuit with two dissimilar metals, resulting in a temperature difference between the metals. In 1827 German scientist Georg Ohm expressed his law in his famous book ""Die galvanische Kette, mathematisch bearbeitet"" (The Galvanic Circuit Investigated Mathematically) in which he gave his complete theory of electricity. In 1829 Antoine-César Becquerel developed the ""constant current"" cell, forerunner of the well-known Daniell cell. When this acid-alkali cell was monitored by a galvanometer, current was found to be constant for an hour, the first instance of ""constant current"". He applied the results of his study of thermoelectricity to the construction of an electric thermometer,"
"Delisle scale The Delisle scale (°D) is a temperature scale invented in 1732 by the French astronomer Joseph-Nicolas Delisle (1688–1768). Delisle was the author of ""Mémoires pour servir à l'histoire et aux progrès de l'Astronomie, de la Géographie et de la Physique"" (1738). In 1732, Delisle built a thermometer that used mercury as a working fluid. Delisle chose his scale using the temperature of boiling water as the fixed zero point and measured the contraction of the mercury (with lower temperatures) in hundred-thousandths. Delisle thermometers usually had 2400 or 2700 gradations, appropriate to the winter in St. Petersburg, as he"
"thermometer: instead of mercury two immiscible liquids are used supporting an index. The thermometer operates in the same way as the mercury version. Electronic thermometers often include a maximum–minimum registering feature. Six's Maximum and Minimum Thermometer Six's thermometer Six's thermometer is a registering thermometer which can record the maximum and minimum temperatures reached over a period of time, for example 24 hours. It is used to record the extremes of temperature at a location, for instance in meteorology and horticulture. It was invented by a British scientist James Six, born in Canterbury, in 1780; the same basic design remains in"
"Bahamas, Belize, and the Cayman Islands. Prominent Dutch mathematician, astronomer and physicist Christiaan Huygens created a clinical thermometer in 1665, to which he added an early form of the centigrade scale by setting the scale to the freezing and boiling points of water. By 1742 Swedish astronomer Anders Celsius created the Celsius temperature scale that was the reverse of the modern scale, in that ""0"" was the boiling point of water, while ""100"" was freezing. It would later be reversed by Swedish botanist Carolus Linnaeus (1707–1778) in 1744. Working independently of Celsius, the Lyonnais physicist Jean-Pierre Christin, permanent secretary of"
"show the hotness and coldness of the air with a tube in which the water level is controlled by the expansion and contraction of the gas. These devices were developed by several European scientists in the 16th and 17th centuries, notably Galileo Galilei. As a result, devices were shown to produce this effect reliably, and the term ""thermoscope"" was adopted because it reflected the changes in sensible heat (the concept of temperature was yet to arise). The difference between a thermoscope and a thermometer is that the latter has a scale. Though Galileo is often said to be the inventor"
"on the surface of the thermometer's bulb and that the ice mass was about a quarter inch thick when they stopped the experiment upon reaching . Franklin wrote, ""From this experiment, one may see the possibility of freezing a man to death on a warm summer's day"". In 1805, American inventor Oliver Evans described a closed vapor-compression refrigeration cycle for the production of ice by ether under vacuum. In 1820 the English scientist Michael Faraday liquefied ammonia and other gases by using high pressures and low temperatures, and in 1834, an American expatriate to Great Britain, Jacob Perkins, built the"
"rain gauge. In 1714, Gabriel Fahrenheit creates a reliable scale for measuring temperature with a mercury-type thermometer. In 1742, Anders Celsius, a Swedish astronomer, proposed the 'centigrade' temperature scale, the predecessor of the current Celsius scale. In 1783, the first hair hygrometer is demonstrated by Horace-Bénédict de Saussure. In 1806, Francis Beaufort introduced his system for classifying wind speeds. The April 1960 launch of the first successful weather satellite, TIROS-1, marked the beginning of the age where weather information became available globally. This was also used to measure the temperature of the surrounding air. A thermometer measures air temperature, or"
"Johann Seebeck invents the thermocouple, Joseph Aspin invents Portland cement, Charles Goodyear invents vulcanized rubber, Louis Daguerre and William Fox Talbot invent silver-based photographic processes, James Clerk Maxwell demonstrates color photography, and Charles Fritts makes the first solar cells using selenium waffles. Before the early 1800s, aluminum had not been produced as an isolated metal. It wasn't until 1825 that Hans Christian Ørsted discovered how to create elemental aluminum via the reduction of aluminum chloride. Since aluminum is a light element with good mechanical properties, it was widely sought to replace heavier less functional metals like silver and gold. Napoleon"
"Fahrenheit hydrometer The Fahrenheit hydrometer is a device used to measure the density of a liquid. It was invented by Daniel Gabriel Fahrenheit (1686–1736), better known for his work in thermometry. The Fahrenheit hydrometer is a constant-volume device that will float in water. In the figure shown here, the hydrometer is floating vertically in a cylinder containing a liquid. At the bottom of the hydrometer is a weighted bulb and at the top is a pan for small weights. To use the hydrometer, one first accurately determines its weight (W) while it is dry. Next, the device is placed in"
"Daniel Quare Daniel Quare (1648 or 1649 – 21 March 1724) was an English clockmaker and instrument maker who Invented a repeating watch movement in 1680 and a portable barometer in 1695. Daniel Quare's origins are obscure. He was possibly a native of Somerset, and is believed to have been born in 1648 or 1649. Nothing is known of his parentage, although he is presumed to have come from a strict Quaker family. No record has been traced of his apprenticeship. On 3 April 1671 he was admitted a brother of the Clockmakers' Company. One of the early members of"
"the ""Académie des sciences, belles-lettres et arts de Lyon"", developed a similar scale in which ""0"" represented the freezing point of water and ""100"" represented boiling. On 19 May 1743 he published the design of a mercury thermometer, the ""Thermometer of Lyon"" built by the craftsman Pierre Casati that used this scale. The medical thermometer was used by Dutch chemist and physician Hermann Boerhaave (1668–1738), as well as his notable students Gerard van Swieten (1700–72) and Anton de Haen (1704–76). It was also utilized around the same time by Scottish physician George Martine (1700–1741). De Haen made particular strides in"
"Jean-Pierre Christin Jean-Pierre Christin (May 31, 1683 – January 19, 1755) was a French physicist, mathematician, astronomer and musician. His proposal in 1743 to reverse the Celsius thermometer scale (from water boiling at 0 degrees and ice melting at 100 degrees, to where zero represented the freezing point of water and 100 represented the boiling point of water) was widely accepted and is still in use today. Christin was born in Lyon. He was a founding member of the """" and served as its Permanent Secretary from 1713 until 1755. His thermometer was known in France before the Revolution as"
"and remarkably close to the present-day value of . Gay-Lussac gave credit for this equation to unpublished statements by his fellow Republican citizen J. Charles in 1787. In the absence of a firm record, the gas law relating volume to temperature cannot be named after Charles. Dalton's measurements had much more scope regarding temperature than Gay-Lussac, not only measuring the volume at the fixed points of water, but also at two intermediate points. Unaware of the inaccuracies of mercury thermometers at the time, which were divided into equal portions between the fixed points, Dalton, after concluding in Essay II that"
"Gerald Pearson Gerald L. Pearson (March 31, 1905 – October 25, 1987) was a physicist whose work on silicon rectifiers at Bell Labs led to the invention of the solar cell. In 2008, he was inducted into the National Inventors Hall of Fame. Pearson was born in Salem, Oregon. He took a bachelor's degree in mathematics and physics from Willamette University and a master's degree in physics from Stanford University. From 1929 he worked as a research physicist at Bell Labs and his early work on temperature-sensitive resistors led to 13 patents on thermistors. After World War II he was"