The History of the Thermometer The History of the Thermometer Sign Up for Our Free Newsletters Thanks, You're in! Health Tip of the Day Sign up There was an error. Please try again. Please select a newsletter. Please enter a valid email address. Did you mean ? GK Hart/Vikki Hart/ Stone/ Getty Images What is a Thermometer? Thermometers measure temperature, by using materials that change in some way when they are heated or cooled. In a mercury or alcohol thermometer the liquid expands as it is heated and contracts when it is cooled, so the length of the liquid column is longer or shorter depending on the temperature. Modern thermometers are calibrated in standard temperature units such as Fahrenheit (used in the United States) or Celsius (used in Canada) and Kelvin (used mostly by scientists). What is a Thermoscope? Before there was the thermometer, there was the earlier and closely related thermoscope, best described as a thermometer without a scale. A thermoscope only showed the differences in temperatures, for example, it could show something was getting hotter. However, the thermoscope did not measure all the data that a thermometer could, for example an exact temperature in degrees.

Early History Several inventors invented a version of the thermoscope at the same time. continue reading below our video Profile of Daniel Fahrenheit In 1593, Galileo Galilei invented a rudimentary water thermoscope, which for the first time, allowed temperature variations to be measured. Today, Galileo's inventioni is called the Galileo Thermometer, even though by definition it was really a thermoscope. It was a container filled with bulbs of varying mass, each with a temperature marking, the buoyancy of water changes with temperature, some of the bulbs sink while others float, the lowest bulb indicated what temperature it was. In 1612, the Italian inventor Santorio Santorio became the first inventor to put a numerical scale on his thermoscope. It was perhaps the first crude clinical thermometer, as it was designed to be place in a patient's mouth for temperature taking. Both Galilei's and Santorio's instruments were not very accurate. In 1654, the first enclosed liquid-in-a-glass thermometer was invented by the Grand Duke of Tuscany, Ferdinand II. The Duke used alcohol as his liquid. However, it was still inaccurate and used no standardized scale.

Fahrenheit Scale - Daniel Gabriel Fahrenheit What can be considered the first modern thermometer, the mercury thermometer with a standardized scale, was invented by Daniel Gabriel Fahrenheit in 1714. Daniel Gabriel Fahrenheit was the German physicist who invented a alcohol thermometer in 1709, and the mercury thermometer in 1714. In 1724, he introduced the standard temperature scale that bears his name - Fahrenheit Scale - that was used to record changes in temperature in an accurate fashion. The Fahrenheit scale divided the freezing and boiling points of water into 180 degrees. 32°F was the freezing pint of water and 212°F was the boiling point of water. 0°F was based on the temperature of an equal mixture of water, ice, and salt. Fahrenheit based his temperature scale on the temperature of the human body. Originally, the human body temperature was 100° F on the Fahrenheit scale, but it has since been adjusted to 98.6°F. Centigrade Scale - Anders Celsius The Celsius temperature scale is also referred to as the "centigrade" scale. Centigrade means "consisting of or divided into 100 degrees".

In 1742, the Celsius scale was invented by Swedish Astronomer Anders Celsius . The Celsius scale has 100 degrees between the freezing point (0°C) and boiling point (100°C) of pure water at sea level air pressure. The term "Celsius" was adopted in 1948 by an international conference on weights and measures. Kelvin Scale - Lord Kelvin Lord Kelvin took the whole process one step further with his invention of the Kelvin Scale in 1848. The Kelvin Scale measures the ultimate extremes of hot and cold. Kelvin developed the idea of absolute temperature , what is called the " Second Law of Thermodynamics ", and developed the dynamical theory of heat. In the 19th century , scientists were researching what was the lowest temperature possible. The Kelvin scale uses the same units as the Celcius scale, but it starts at ABSOLUTE ZERO , the temperature at which everything including air freezes solid. Absolute zero is O K, which is - 273°C degrees Celsius.

Mercury Thermometer invented by Daniel Gabriel Fahrenheit in year 1714 Invented by : Daniel Gabriel Fahrenheit Invented in year : 1714 Thermometer is an instrument which is used to measure temperature. It measures temperature by using materials that change in some way when they are heated or cooled. In a mercury or alcohol thermometer the liquid expands as it is heated and contracts when it is cooled, so the length of the liquid column is longer or shorter depending on the temperature. Modern thermometers are calibrated in standard temperature units such as Fahrenheit or Celsius. Mercury Thermometer is actually a mercury-in-glass thermometer. There are Calibrated marks on the tube which allow the temperature to be read by the length of the mercury within the tube, which varies according to the heat given to it. To increase the sensitivity, there is usually a bulb of mercury at the end of the thermometer which contains most of the mercury; expansion and contraction of this volume of mercury is then amplified in the much narrower bore of the tube. The space above the mercury may be filled with nitrogen or it may be a vacuum. The predecessor to the thermometer were called Thermoscopes. It was Galileo Galilei who is known to be the inventor of the first Thermometer.

He invented a rudimentary water thermometer in 1593 which merely indicated temperature differences. Many several inventors invented a version of the thermoscope at the same time but it was Italian inventor Santorio Santorio who put a numerical scale on the instrument in 1612. Daniel Gabriel Fahrenheit (1686-1736) was the German physicist who invented the Alcohol Thermometer in 1709, and the Mercury Thermometer In 1714. In 1724, he introduced the temperature scale that bears his name - Fahrenheit Scale. The key to Fahrenheit's thermometer was a new method for cleaning mercury that enabled it to rise and fall within the tube without sticking to the sides. Mercury was an ideal substance for reading temperatures since it expanded at a more constant rate than alcohol and is able to be read at much higher and lower temperatures. Fahrenheit based his scale on three reference points of temperature. The zero point was determined by placing the thermometer in brine: a mixture of ice, water, and ammonium chloride, a salt, was used. This was a type of frigorific mixture. The mixture automatically stabilized its temperature at 0 °F.

The thermometer was placed in the mixture and the liquid in the thermometer was allowed to descend to its lowest point. The second point was 32 degree found by putting the thermometer in still water as ice is just forming on the surface. The third point, the 96 degree, was the level of the liquid in the thermometer when held in the mouth or under the armpit. Fahrenheit noted that, using this scale, mercury boils at around 600 degrees. Later, other scientists observed that water boils about 180 degrees higher than the freezing point and decided to redefine the degree slightly to make it exactly 180 degrees higher. It is for this reason that normal body temperature is 98.6 on the revised scale while it was 96 on Fahrenheit's original scale. Development in the Invention Mercury Thermometer In 1731 the Frenchman, René Antoine Ferchauld de Réamur (1683-1757) proposed a thermometer scale on which the freezing point of water was 0° and the boiling point was 80°. But it the Réamur scale is not in use today.

In 1742 a Swedish scientist named Anders Celsius (1701-1744) devised a thermometer scale dividing the freezing and boiling points of water into 100 degrees. Celsius chose 0 degrees for the boiling point of water, and 100 degrees for the freezing point. A year later, the Frenchman Jean Pierre Cristin (1683-1755) inverted the Celsius scale to produce the Centigrade scale used today (freezing point 0°, boiling point 100°). By international agreement in 1948 Cristin's adapted scale became known as Celsius and is still in use today. In 1848 Sir William Thomson, Baron Kelvin of Largs, Lord Kelvin of Scotland (1824 - 1907) proposed the absolute temperature scale with zero degrees being the theoretical lowest temperature possible where molecular motion ceases. Kelvin defined 1 Kelvin degree as being equal to one Celsius degree. The Degree Kelvin is the current Standard Unit of temperature measurement.

Role of Mercury Thermometer in the Improvement Of Human Life Because of the Mercury thermometer scientists came to know that mercury has better thermoconductiity and they have a greater range of readings Clinical Thermometers made diagnose and treatment of various diseases easy Mercury started to become widely used in Meteorology and Electrical instruments It lead to the invention of other types of thermometers which were used for varios purposes It also encouraged the glass industry Other Inventions Who Invented the Thermometer - Fahrenheit Celsius and Kelvin Scales. Santorio invented several instruments, a wind gauge, a water current meter, the "pulsilogium," and a thermoscope, a precursor to the thermometer. Santorio was the first to apply a numerical scale to his thermoscope, which later evolved into the thermometer. Daniel Gabriel Fahrenheit Daniel Gabriel Fahrenheit (1686-1736) was the German physicist who invented the alcohol thermometer in 1709, and the mercury thermometer in 1714. In 1724, he introduced the temperature scale that bears his name - Fahrenheit Scale. Anders Celsius The Celsius temperature scale is also referred to as the "centigrade" scale.

Centigrade means "consisting of or divided into 100 degrees". The Celsius scale, invented by Swedish Astronomer Anders Celsius (1701-1744), has 100 degrees between the freezing point (0 C) and boiling point (100 C) of pure water at sea level air pressure. The term "Celsius" was adopted in 1948 by an international conference on weights and measures. Anders Celsius was born in Uppsala, Sweden in 1701, where he succeeded his father as professor of astronomy in 1730. It was there that he built Sweden's first observatory in 1741, the Uppsala Observatory, where he was appointed director. He devised the centigrade scale or "Celsius scale" of temperature in 1742. He was also noted for his promotion of the Gregorian calendar, and his observations of the aurora borealis. In 1733, his collection of 316 observations of the aurora borealis was published and in 1737 he took part in the French expedition sent to measure one degree of meridian in the polar regions.

In 1741, he directed the building of Sweden's first observatory. One of the major questions of that time was the shape of the Earth. Isaac Newton had proposed that the Earth was not completely spherical, but rather flattened at the poles. Cartographic measuring in France suggested that it was the other way around - the Earth was elongated at the poles. In 1735, one expedition sailed to Ecuador in South America, and another expedition traveled to Northern Sweden. Celsius was the only professional astronomer on that expedition. Their measurements seemed to indicate that the Earth actually was flattened at the poles. Celsius was not only an inventor and astronomer, but also a physicist. He and an assistant discovered that the aurora borealis had an influence on compass needles. However, the thing that made him famous is his temperature scale, which he based on the boiling and melting points of water. This scale, an inverted form of Celsius' original design, was adopted as the standard and is used in almost all scientific work. Anders Celsius died in 1744, at the age of 42. He had started many other research projects, but finished few of them.

Among his papers was a draft of a science fiction novel, situated partly on the star Sirius. Super scientist biography of Anders Celsius. Lord William Thomson Kelvin Lord Kelvin took the whole process one step further with his invention of the Kelvin Scale in 1848. The Kelvin Scale measures the ultimate extremes of hot and cold. Kelvin developed the idea of absolute temperature , what is called the "Second Law of Thermodynamics", and developed the dynamical theory of heat. Sir William Thomson, Baron Kelvin of Largs, Lord Kelvin of Scotland (1824 - 1907) studied at Cambridge University, was a champion rower, and later became a Professor of Natural Philosophy at the University of Glasgow. Among his other achievements was the 1852 discovery of the "Joule-Thomson Effect" of gases and his work on the first transatlantic telegraph cable (for which he was knighted), and his inventing of the mirror galvanometer used in cable signaling, the siphon recorder, the mechanical tide predictor, an improved ship's compass. Mathematician and physicist, one of the leading physical scientists and greatest teachers of his time.

Lord William Thomson Kelvin Question Results - The Weather Network View Results Who invented the mercury thermometer? Daniel Gabriel Fahrenheit was the German physicist who invented a alcohol thermometer in 1709, and the mercury thermometer in 1714. ICYMI: Earth Week: The scoop on spring melts and dog poop... Popular Right Now Temperature: Facts, History & Definition Temperature: Facts, History & Definition By Kim Ann Zimmermann, Live Science Contributor | September 20, 2013 10:30pm ET MORE Credit: Dreamstime Temperature is a numerical representation of hot or cold compared against baselines, typically the point at which water freezes and boils. In most in instances, temperature measures how much heat there is in a particular entity —in a liquid, such as water, or a solid, such as soil. In meteorology, temperature measures the heat content of the atmosphere. The instrument used to measure temperature is a thermometer, a word derived from the Greek thermos, meaning "hot," and metron, "measure." History of the thermometer Galen, a Greek scientist and physician, made the first attempt at measuring temperature in A.D. 170.

He documented a standard "neutral" temperature of equal parts of boiling water and ice. He added four degrees of heat and four degrees of cold on either side of this neutral temperature. The concept of measuring temperature is fairly new. The thermoscope — essentially a thermometer without a scale — was the precursor to the modern thermometer. There were several inventors working on thermoscopes around 1593, but the most well known is Galileo Galilei , an Italian inventor who also improved upon (but did not invent) the telescope . A thermoscope could show the differences in temperature, allowing observers to know if something was getting hotter or colder. However, the thermoscope could not provide an exact temperature in degrees. In 1612, the Italian inventor Santorio Santorio added a numerical scale on his thermoscope and it was used to take human temperature. Ferdinand II, the Grand Duke of Tuscany, followed in 1654, inventing the first enclosed thermometer, using alcohol as a liquid. But it still lacked a standardized scale and was not very accurate. Around the same time, German physicist Daniel Gabriel Fahrenheit met Olaus Roemer, a Danish astronomer, who developed an alcohol-based thermometer using wine.

He marked two points on his thermometer — 60 to mark the temperature of boiling water and 7.5 as the point where ice melted. In 1714, Fahrenheit refined Roemer’s invention and developed the first modern thermometer — the mercury thermometer with more refined measurements. The mercury expands or contracts as the temperature rises or falls. Fahrenheit had invented an alcohol thermometer in 1709 prior to unveiling its mercury counterpart, which proved to be more accurate. Ten years later, he unveiled his namesake Fahrenheit scale, which divided the freezing and boiling points of water into 180 degrees. It established 32 degrees was the freezing pint of water and 212 degrees was the boiling point of water. An equal mixture of water, ice and ammonium chloride, a salt, was used to set the temperature of 0. The rise of the temperature scales Fahrenheit is one of three major temperature scales used today, with the other two being Celsius and Kelvin. Fahrenheit is the standard used for measuring temperature in the United States, but most of the rest of the world uses Celsius.

Not too long after the Fahrenheit scale was unveiled, Swedish astronomer Anders Celsius came out with his temperature scale, which is referred to as the Celsius scale. It is sometimes called the centigrade scale, because it is divided into 100 degrees separating the boiling and freezing points of water. The original scale set 0 as the boiling point of water and 100 as the freezing point, but he flipped it around soon after inventing the scale. The term Celsius was adopted in 1948 by an international conference on weights and measures and the scale is the preferred temperature gauge for scientific applications as well as most of the world outside of the United States. Lord Kelvin of Scotland chimed in with his temperature gauge in 1848, known as the Kelvin scale. He based it on the idea of absolute temperature, a theoretical temperature at which all substances have no heat energy. There are no negative numbers on the Kelvin scale, 0 K being the coldest temperature possible. Absolute zero converts to minus 273.15 C and minus 459.67 F. The Kelvin scale is commonly used in scientific applications.

The units on the Kelvin scale are the same size as those of the Celsius scale, except that the Kelvin scale sets the lowest temperature at 0. Conversion rates Fahrenheit to Celsius: Subtract 32, then multiply by 5, then divide by 9 Celsius to Fahrenheit: Multiply by 9, divide by 5, then add 32 Fahrenheit to Kelvin: Subtract 32, multiply by 5, divide by 9, then add 273.15. Kelvin to Fahrenheit: Subtract 273.15, multiply by 1.8, then add 32. Kelvin to Celsius: Add 273 Celsius to Kelvin: Subtract 273 Author Bio Kim Ann Zimmermann, Live Science Contributor Kim Ann Zimmermann is a contributor to Live Science. She holds a bachelor’s degree in communications from Glassboro State College. Latest on Temperature: Facts, History & Definition The Inventors of the Thermometer By Mary Bellis Updated September 06, 2016. What can be considered the first modern thermometer , the mercury thermometer with a standardized scale, was invented by Daniel Gabriel Fahrenheit in 1714.

History Various people are credited with inventing of the thermometer including Galileo Galilei, Cornelis Drebbel, Robert Fludd and Santorio Santorio. The thermometer was not a single invention, however, but a process. Philo of Byzantium (280 BC–220 BC) and Hero of Alexandria (10–70 AD) discovered that certain substances, notably air, expand and contract, and described a demonstration in which a closed tube partially filled with air had its end in a container of water. The expansion and contraction of the air caused the position of the water/air interface to move along the tube. This was later used to 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, and eventually were called thermoscopes. The difference between a thermoscope and a thermometer is that the latter has a scale. continue reading below our video Profile of Daniel Fahrenheit Though Galileo is often said to be the inventor of the thermometer, what he produced were thermoscopes.

Daniel Fahrenheit Daniel Gabriel Fahrenheit was born in 1686 in Germany into a family of German merchants, however, he lived most of his life in the Dutch Republic. Daniel Fahrenheit married Concordia Schumann, daughter of a well-known business family. Fahrenheit began training as a merchant in Amsterdam after his parents died on August 14, 1701, from eating poisonous mushrooms. However, Fahrenheit had a strong interest in natural science and was fascinated by new inventions such as the thermometer. In 1717, Fahrenheit became a glassblower, making barometers, altimeters, and thermometers. From 1718 onwards, he was a lecturer in chemistry. During a visit to England in 1724, he was elected a Fellow of the Royal Society. Daniel Fahrenheit died in The Hague and was buried there at the Cloister Church. Fahrenheit Scale The Fahrenheit scale divided the freezing and boiling points of water into 180 degrees. 32°F was the freezing pint of water and 212°F was the boiling point of water. 0°F was based on the temperature of an equal mixture of water, ice, and salt. Daniel Fahrenheit based his temperature scale on the temperature of the human body.

Originally, the human body temperature was 100° F on the Fahrenheit scale, but it has since been adjusted to 98.6°F. Inspiration for the Mercury Thermometer Fahrenheit met Olaus Roemer, a Danish astronomer, in Copenhagen. Roemer had invented an alcohol (wine) thermometer. Roemer's thermometer had two points, 60 degrees as the temperature of boiling water and 7 1/2 degrees as the temperature of melting ice. At that time, temperature scales were not standardized and everybody made up their own scale. Fahrenheit modified Roemer's design and scale, and invented the new mercury themometer with a Fahrenheit scale. The first physician that put thermometer measurements to clinical practice was Herman Boerhaave (1668–1738). In 1866, Sir Thomas Clifford Allbutt invented a clinical thermometer that produced a body temperature reading in five minutes as opposed to 20. Daniel Gabriel Fahrenheit Essay - 609 Words (“Fahrenheit, Gabriel Daniel (1686-1736)”) The great man himself, Daniel Fahrenheit. Boiling water, freezing water and the temperature of a human body: these were the key points of the Fahrenheit scale.

These three temperatures were chosen to act as the basis of the Fahrenheit temperature scale. The scale was named after Daniel Gabriel Fahrenheit, who invented the first non-alcohol based thermometer. Fahrenheit’s thermometers were popular to the public, accepted by the church and influential because they were the most accurate thermometers of the time. Fahrenheit’s thermometers caught the eye of the public people immediately. The public was so intrigued by the inventions because they were the most accurate thermometers invented at that time (“Daniel Gabriel Fahrenheit: Biography from Answers.com”). Fahrenheit’s thermometers were also the first thermometers to be invented without the use of an alcohol and water based mixture, instead of this traditional concoction, Daniel used mercury (Asimov 184). He used mercury because the expansion was not affected by its surroundings. . The new list of ingredients had the public excited to use the revolutionary device. Fahrenheit’s thermometers could also be used at higher altitudes than their alcoholic counter-parts and still be accurate (“Gabriel Daniel Fahrenheit Biography”). This was because the altitude did not affect the expansion of mercury as much as it affected the expansion of the alcoholic mixture.

Alongside his revolutionary inventions, Daniel also created his own temperature scale, which he called “The Fahrenheit Scale” (“Daniel Gabriel Fahrenheit Biography”). This new scale had the population buzzing because it had more depth than the other temperature scales at the time. Fahrenheit’s invention of the mercury thermometer was revolutionary and was a new way to measure temperatures, which had the public yearning to see how it was done. The... Daniel Gabriel Fahrenheit Essay ...Daniel Gabriel Fahrenheit On a brisk spring 12th to the 24th (resources are mixed) of May in 1686, a Mr. Daniel Gabriel Fahrenheit was brought into the sweet town of Danzig. Daniel did not grow up with both of his parents. His family members were merchants that moved from one city another. Fahrenheit's great-grandfather had loved in Rostock, although research suggests that the... 338 Words | 1 Pages Fahrenheit Essay ...Junior Honors English A 3 March 2013 451 Symbolism Throughout the entire novel of Fahrenheit 451, Ray Bradbury’s use of symbolism is indisputable. Bradbury takes his readers on a futuristic adventure into a world where gaining knowledge through books and intellectual thoughts are outlawed.

Through his writing, he indicates the possibility of what current day society could turn into if it lacked education and continued on the road of self destruction. Montag, the main... 1192 Words | 4 Pages Fahrenheit Essay ...Ray Bradbury is a master of characterization techniques. He uses his expertise, such as indirect characterization, in the creation of Fahrenheit 451. In addition to learning about the explicit qualities of Bradbury’s characters, readers receive deeper insight as we carefully read his stories. In Fahrenheit 451, we learn more indirect information about the protagonist, Guy Montag, through the words used to introduce this character. We have a clear view of Montag’s... 1156 Words | 3 Pages Essay about Daniel ...TORT QUESTION 1: A seven-year-old boy followed his dog into Mr. Howe’s backyard. The boy fell into a large hole dug by Mr. Howe in preparation for a tree that had been ordered. The boy broke his arm in the fall. At the hospital a doctor employed there for four years treated the boy. The doctor did not set the boy’s arm because he failed to see on the x-ray and indication that the arm was broken. The arm healed improperly.

When the boy kept complaining, his parents took him to the family... 3257 Words | 10 Pages Essay on Daniel.... ...﻿Bureaucracy and Formal Organization The term BUREAUCRACY is traditionally associated with the administration of GOVERNMENT and its various agencies. (The definition of the word bureaucratie in the 1789 supplement to the dictionary of the French Academy was "power, influence of the heads and staff of government bureaux.") Bureaucracy is also basic to the operation of private corporations, political parties, unions, churches and any other large modern organization. Its association with... 3306 Words | 7 Pages Essay on Daniel ...﻿Business analyst’s view of software development life cycle models General Approach 1 Linear or Phased Approaches 1 Waterfall 1 V Model 4 Incremental Development 6 Iterative Approaches 8 Spiral 8 Microsoft Solutions Framework 11 Rationale Unified Process 13 Agile Approaches 15 Rapid Application Development 15 DSDM 15 Extreme Programming 18 General Approach Regardless of the time an activity takes whether they are done simultaneously or in long planned phases...

4886 Words | 17 Pages Fahrenheit Essay ... The book “Fahrenheit 451″ by Ray Bradbury was about a fireman name Guy Montag. Montag does the opposite from what regular fireman do. He starts fires instead of putting them out. Books in Montag society is forbidden to read and if caught reading the book would be set on fire. Instead of reading, that society watches large amounts of television as big as the wall and listens to the radio attached to their ears. It was not normal for pedestraisn to talk and have meaningful... 668 Words | 2 Pages Fahrenheit Essay ...for the comfort of others. Overall, people should become more open minded and except the fact that they are going to see or hear things they do not want to. I think if you do not like something, then do not do anything that has to do with it. In Fahrenheit 451 by Ray Bradbury he shows that censoring material causes people to become lazy and not think. Around the beginning of part 2 Faber says, “Do you know why books such as this are so important? Because they have quality. And...

708 Words | 2 Pages Daniel Gabriel Fahrenheit facts, information, pictures | Encyclopedia.com articles about Daniel Gabriel Fahrenheit (b. Danzig [Gdansk], Poland, 24 May 1686; d. The Hague, Natherlands, 16 September 1736) experimental physics. Fahrenheit was the scion of a wealthy merchant family that had come to Danzig from Königsberg in the middle of the serventeenth century. His father, Daniel, married Concordia Schumann, the daughter of Danzig wholesaler. From this union there were five children, three girls and two boys, of whom Daniel was the eldest. In 1701 Fahrenheit’s parents died suddenly, and his guardian sent him to Amsterdam to learn business. It was there, apparently, the Fahrenheit first became acquainted with, and then fascinated by, the rather specialized and small but rapidly growing business of making scientific instruments. About 1707 he began his years of wandering, during which he acquired the techniques of his trade by observing the practices of other scientists and instrument makers. He traveled throughout Germany, visiting his native city of Danzig as well as Berlin, Halle, Leipzig, and Dresden.

He met Olaus Roemer in Copenhagen in 1708, and in 1715 he entered into correspondence with Leibniz about a clock for determining longitude at sea. In 1714 Christian von Wolff published a description of one of Fahrenheit’s early thermometers in the Acta eruditorum. Fahrenheit returned to Amsterdam in 1717 and established himself as a maker of scientific instruments. There he became acquainted with three of the greatest Dutch scientists of his era: W. J. ’sGravesande, Hermann Boerhaave, and Pieter van Musschenbroek. In 1724 he was admitted to the Royal Society, and in the same year he published in the Philosophical Transactions his only scientific writings, five brief articles in Latin. Just before his death in 1736, Fahrenheit took out a patent on a pumping device that he hoped would be useful in draining Dutch polders. Fahrenheit’s most significant achievement was his development of the standard thermometric scale that bears his name.

Nearly a century had passed since the construction of the first primitive thermometers, and although many of the basic problems of thermometry had been solved, no standard thermometric scale had been developed that would allow scientists in different locations to compare temperatures. About 1701 Olaus Roemeṙ had constructed a spirit thermometer based upon two universal fiducial points. The upper fixed point, determined by the temperature of boiling water, was labeled 60°; the lower fixed point, determined by the temperature of melting ice, was set at 7–1/2°. This latter, seemingly arbitrary, number was chosen to allow exactly 1/8 of the entire scale to stand below the freezing point. Since 00 on the Roemer scale approximated the temperature of an ice and salt mixture (which was widely considered to be at the coldest possible temperature), all readings on Roemer’s thermometer were assumed to be positive. Roemer did not publish anything about his thermometer, and its existence was unknown to most of his contemporaries except Fahrenheit, who thought mistakenly that his own thermometric scale was patterned after Roemer’s. In 1708, while visiting Roemer, Fahrenheit watched the Danish astronomer as he graduated several thermometers.

These particular instruments were being graduated to a scale of 22–1/2°, or 3/8 of Roemer’s standard scale of 60°. Since most of the scale would then be in the temperate range, it is probable that Roemer was designing them for meteorological purposes. In a letter addressed to Boerhaave, Fahrenheit gave the following description of Roemer’s procedure. I found that he had stood several thermometers in water and ice, and later he dipped these in warm water, which was at blood-heat [welches blutwarm war], and after he had marked these two limits on all the thermometers, half the distance between them was added below the point in the vessel with ice, and the whole distance divided into 22–1/2 parts, beginning with 0 at the bottom then 7–1/2 for the point in the vessel with ice and 22–1/2 degrees for that at blood-heat. 1 The problem with Fahrenheit’s account is that he took Roemer’s “blood-warm” (22–1/2°) to be a primary fiducial point, fixed quite literally at the temperature of the human blood.

In fact, 22–1/2° on the Roemer scale is considerably below body temperature (by about 15° on the modern Fahrenheit thermometer). Furthermore, Roemer used boiling water (set at 60°), not blood temperature, as his upper fixed point. The simplest explanation for Fahrenheit’s misunderstanding of the Roemer scale seems to lie in the ambiguity of the term “blood-warm.” It can mean either a tepid heat or the exact temperature of the human blood. 2 Roemer probably intended to convey the former meaning, and Fahrenheit obviously understood the latter one. When Fahrenheit began producing thermometers of his own, he graduated them after what he believed were Roemer’s methods. The upper fixed point (labeled 22–1/2°) was determined by placing the bulb of the thermometer in the mouth or armpit of a healthy male. 3 The lower fixed point (labeled 7–1/2°) was determined by an ice and water mixture. In addition, Fahrenheit divided each degree into four parts, so that the upper point became 90° and the lower one 30°.

Later (in 1717) he moved the upper point to 96° and the lower one to 32° in order to eliminate “inconvenient and awkward fractions.” 4 In an article on the boiling points of various liquids, Fahrenheit reported that the boiling temperature of water was 212° on his thermometric scale. This figure was actually several degrees higher than it should have been. After Fahrenheit’s death it became standard practice to graduate Fahrenheit thermometers with the boiling point of water (set at 212°) as the upper fixed point. As a result, normal body temperature became 98.6° instead of Fahrenheit’s 96°. This variant of the Fahrenheit scale became standard throughout Holland and Britain. Today it is used for meteorological purposes in most English-speaking countries. Fahrenheit knew that the boiling temperature of water varied with the atmospheric pressure, and on this Principle he constructed a hypsometric thermometer that enabled one to determine the atmospheric Pressure directly from a reading of the boiling point of water. He also invented a hydrometer that became a model for subsequent developments.

In the early eighteenth century, it was not at all unusual for a person without formal scientific training to be admitted to the Royal Society. Makers of scientific instruments could be particularly valuable members because they often operated on the farthest frontiers of scientific knowledge, defining universal constants on which to scale their instruments and isolating the variables that affected their operation. In order to make reliable instruments that would be useful to the scientific community as a whole, Fahrenheit was obliged to concern himself with a wide variety of scientific Problems: measuring the expansion of glass, assessing the thermometric behavior of mercury and alcohol, describing the effects of atmospheric pressure on the boiling points of liquids and establishing the densities of various substances. His direct contributions, it is true, were small, but in raising appreciably the level of precision that was obtainable in many scientific observations, Fahrenheit affected profoundly the course of experimental physics in the eighteenth century. NOTES 1. Quoted from W.E. Knowles middleton, A History of the Thermometer and Its Use in Meteorology (Baltimore, 1966), p. 71. 2. J. U. W.

Grimm’s Deutsches Wörterbuch gives “tepid”as the definition of blutwarm. Blutwärm (“blood-heat”) is defined as the temperature of the blood. Francis Hauksbee, in his Physico-Mechanical Experiments, wrote; “I caus’s some eater to be heated about Blood-warm”(quoted in the Oxford English Dictionary, I,933). The French translation (Paris, 1754, I,385) reads “hellip; je fis chauffer de I’eau jusqu’àa ce qu’elle fôt un peu plus que tiéd. (ldquo;I caused some water to be heated until it was a little more than tepid.”) 3. It seems curious that Fathrenheit should have stipulated that of the subject be a man. Perhaps this is owing to some remanant of the once widely held notion that women naturally have a lower body temperature than men. (See Jacques Roger, Les sciences de la die dans la penséee francaise du XVIII e; siécle [Paris 1963], pp. 84 ff.) 4. Middleton, loc. cit.

BIBLIOGRAPHY I. Original Works. All of Fahrenheit’ published works appeared in the Philosophical Transactions of the Royal Society, 33 (1724): “Experimenta Circa gradum caloris liquorum nonnullorum ebullientium institua,” pp. 1–3;“Experimenta Observationes de congelatione aquae in vacuo factae,” pp. 78–84; “Materium quarundum gravitates specificae diversis temporibus ad varios scopos explorratae” Pp.114–141; “Araemetri novi descript,” pp. 179–180. These are translated into German in Ostwalds Klassiker der Exacten Wissenschaften, no. 57 (Leipzig, 1954), pp. 3–18. II. Secondary Literature. There is an enormous quantity of literature on Fahrenheit. The following list is limited to recent articles of importance: Florian Cajori, “Note on the Fahrenheit Scale” in Isis, 4 (1921), 17–22; Ernst Cohen and W. A. T.

Cohen-De Meester, “Daniel Gabriel Fahrenheit,” in verhandeligen der Konenklijke akademie uan wetenschappen, sec. 1, 16 no. 2 (1937), 1–37; N. Ernest Dorsey, “Fahrenheit and Roemer,” in Journal of the Washington Academy of Sciences, 36, no. 11 (1946),361–372;and W. E. knowles Middleton, A History of the Thermometer and Its Use in Meterorology (Baltimore, 1966), pp. 66–79. J. B. Gough Pick a style below, and copy the text for your bibliography. MLA GERMAN PHYSICIST 1686–1736 Observations are the heart of the scientific method, but human perception is faulty when it comes to observing "absolutes." That is, one may be able to say that this liquid is hotter than that liquid, but not by how much, nor their exact temperatures.

For science to be meaningful and its results reproducible, some external mechanism for making (and comparing) measurements that can be used by scientists must exist. Daniel Gabriel Fahrenheit was a German physicist living in the Netherlands in the early eighteenth century. Like many of his contemporaries, he was interested in a great many phenomena, but the one phenomenon that really seized his attention was the boiling of liquids. Fahrenheit discovered that pure liquids boil at fixed temperatures, which are not influenced by the continued application of heat. He described his reaction to this discovery in his Philosophical Transactions (1724): "I was at once inflamed with a great desire to make for myself a thermometer of the same sort [a water-based thermometer], so that I might with my own eyes perceive this beautiful phenomenon of nature, and be convinced of the truth of the experiment." Fahrenheit could not make a "thermometer of the same sort," despite repeated attempts. The type of thermometer that he was trying to make used water, open to the atmosphere, as the fluid of expansion. His original thermometers were thus sensitive to air pressure, and acted as both barometers and thermometers at the same time. Fahrenheit subsequently recognized that both alcohol and mercury expanded with heat.

He built closed bulb thermometers that contained alcohol (1709) and mercury (1714), thereby inventing the modern thermometer. With these instruments, he was able to make much more accurate and more consistent measurements of temperature. And he discovered, among other things, that water can be supercooled (cooled below its normal freezing point), and that the boiling point of a liquid is not a constant, but is a function of atmospheric pressure. Fahrenheit used supercooled water (from a mixture of water, ice, and sal ammoniac [ammonium chloride]) to establish his zero point, and his own body temperature to establish what would be 100 degrees. (Of course, we now gauge normal body temperature to be 98.6°F.) Fahrenheit's thermometers were the first to enable accurate and reproducible measurements of temperature. Until the 1970s, the Fahrenheit scale was in common use in all English-speaking countries. Since then, the Celsius scale has been adopted by most countries (not including the United States ). see also Temperature.

Fahrenheit: Facts, History & Conversion Formulas Fahrenheit: Facts, History & Conversion Formulas By Kim Ann Zimmermann, Live Science Contributor | September 24, 2013 05:51pm ET MORE Credit: Shane Trotter | Shutterstock Fahrenheit is a temperature scale that bases the boiling point of water at 212 and the freezing point at 32. It was developed by Daniel Gabriel Fahrenheit, a German-born scientist who lived and worked primarily in the Netherlands. Today, the scale is used primarily in the United States and some Caribbean countries. The rest of the world uses the Celsius scale. In 1714, Fahrenheit developed the first modern thermometer — the mercury thermometer, with more refined measurements than previous temperature gauges. Fahrenheit’s thermometer was a take on an alcohol-based thermometer invented by Olaus Roemer, a Danish scientist. Roemer marked two points on his thermometer — 0 as the lowest point, 60 as the temperature of boiling water, 7.5 as the point where ice melted and 22.5 as body temperature. Because the mercury thermometer was more accurate, Fahrenheit decided to expand the Roemer scale by multiplying its values by four.

He made adjustments to those metrics based on further research, even putting the thermometer under his wife’s armpit to gain a body temperature. In his initial scale, the zero point was determined by placing the thermometer in an equal mix of ice, water, and salt (ammonium chloride). This stable temperature was set as 0. The second point, at 32, was an equal mix of ice and water. The third point, 96, was approximately the human body temperature, referred to as "blood-heat." While Fahrenheit documented in an article that he used the boiling and freezing points of water to build his scale, there were some conspiracy theorists who thought he had other motives for using those numbers. Some believe that Fahrenheit was a Freemason, and because there are 32 degrees of enlightenment, he chose to use 32 as the melting temperature of water. However, there is no record that the scientist was a Freemason. In yet another story, it is said that Fahrenheit believed that a person would freeze to death at 0 degrees and would succumb to a heat stroke at 100.

The scale was recalibrated after his death, marking 32 and 212 as the exact melting and boiling points of plain water, minus the salt. It also makes the normal body temperature 98.6 , which is what has become the standard. That change made Celsius-to-Fahrenheit conversions easier. The size of the Fahrenheit "degree" is five-ninths the size of the same unit on Celsius and Kelvin temperature scales. This makes it easier to provide more exact measurements without using fractions in the Fahrenheit scale. The Fahrenheit and Celsius scales converge at minus 40 F, so that minus 40 F and minus 40 C represent the same temperature. Who uses Fahrenheit? Fahrenheit has widely been replaced by Celsius in most countries and for most applications. In the late 1960s and 1970s, the Celsius scale was phased in by governments around the world as part of the move to standardize on metric measurements. Today, the scale is primarily used in the United States, and is also used in the Cayman Islands, Palau, Bahamas and Belize. While other branches of science use the Celsius scale, U.S. meteorologists continue to use the Fahrenheit scale for weather forecasting and reporting.

Canadian meteorologists sometimes use the Fahrenheit scale alongside the Celsius scale. Supporters of the Fahrenheit scale note that a degree on the Fahrenheit scale is the temperature change that the average person can detect. Conversion formulas Fahrenheit to Celsius: Subtract 32, then multiply by 5, then divide by 9 Celsius to Fahrenheit: Multiply by 9, divide by 5, then add 32 Fahrenheit to Kelvin: Subtract 32, multiply by 5, divide by 9, then add 273.15 Kelvin to Fahrenheit: Subtract 273.15, multiply by 1.8, then add 32 Related: Daniel Gabriel Fahrenheit --� Kids Encyclopedia | Children's Homework Help | Kids Online Dictionary | Britannica On the dial of a modern outdoor thermometer are an inner scale of Fahrenheit numbers and an outer © Myotis/Shutterstock.com (16861736). The German physicist Daniel Gabriel Fahrenheit invented the alcohol thermometer in 1709 and the mercury thermometer in 1714. In 1724 he introduced the temperature scale that bears his name.

Daniel Gabriel Fahrenheit was born in Gdansk, Poland, on May 24, 1686. After studying and traveling he eventually settled in Amsterdam, the Netherlands, where he became a maker of scientific instruments. He discovered a method for cleaning mercury so that it would not stick to a glass tube. This was essential to devising his mercury thermometer. He died in The Hague, the Netherlands, on Sept. 16, 1736. For fixed points on his temperature scale, Fahrenheit took the temperature of a mixture of ice water and salt as the low point and the human body temperature as the high point. The space between he divided into 96 degrees. He later adjusted the scale slightly so as not to have fractions for the freezing and boiling points of water. The freezing point of water then became 32° F (0° C) and the boiling point 212° F (100° C). (See also heat ; thermometer .) Page 1 of 1 "Fahrenheit, Daniel Gabriel." Compton's by Britannica. Britannica Online for Kids.

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Question: Who invented the mercury thermometer? Daniel Gabriel
Answer: Farenheit