Air expands and contracts with temperature. So does water. So do metals like mercury. Even before Galileo - who understood that science began with meticulous measurement - savants had worked out that it ought to be possible to use air and water to invent a "ruler" that would mark the grades from cold to hot and back again. They experimented with thermoscopes involving a column of air in a tube with one end in a container of coloured water. In 1610 Galileo tried it with wine instead, and so is credited with the first alcohol thermometer.
The first sealed thermometer was designed in 1641 for the grand duke of Tuscany: it used alcohol, and it had degree marks. But the man credited with using the freezing point of water as the "zero" or starting point was a Londoner, Robert Hooke, in 1664. An astronomer called Roemer in Copenhagen chose ice and the boiling point of water as his two reference points, and started keeping weather records, but there were still uncertainties about how to devise an accurate scale that would be reliable everywhere.
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.
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.
The Thermometer is probably the one weather instrument that just about everyone has used, at one time or another. Thermometers can be as basic as one hanging on a tree in the back yard, that you can read from the kitchen window, to a very sophisticated electronic thermometer that feeds hourly temperature data into your home computer. They all serve the same purpose of telling us what the temperature is outside and plays a major role in how we dress or prepare for each day.Galileo invented the first thermometer in the late 1600s. The exact year is not known, but historians estimate that it was in 1593. He was a famous Italian Mathematician and Scientist whose inventions and mathematical theories are still in use today. The basic principle behind a thermometer, the expansion of air by heat and contraction by cold, was know many hundreds of years earlier. As far back as 300 B.C. experiments of Philo of Byzantium illustrated this principle. Along with Galileo, several other scientists developed better and more accurate thermometers. They were Marin Mersenne, Otto Von Guericke, Robert Boyle, Christian Huygens and Sir Isaac Newton.Gabriel Fahrenheit invented the first reliable mercury thermometer in 1714. His scale is still used today. Anders Celsius had a major role in developing another popular scale for thermometers. In 1742 he proposed that the boiling point of water be represented by 0 degrees and the melting point of ice be 100 degrees. This scale was widely accepted and it still used today for scientific work. Today’s Celsius scale is reversed with boiling water equal to 100 and melting ice 0 degrees. Jean Pierre Christin proposed this change in 1743.Today’s thermometers are made in different ways. The most common is the alcohol or mercury thermometer. These are the most accurate and measure the air temperature by the expansion of the fluid in a thin, enclosed glass tube. Another way of measuring air temperature is by measuring the expansion of different metals. These are called Expansion Thermometers. These are made of two different metals that expand and contract at different rates when the air temperature changes. The metals are fused together and wound like a spring. When the temperature changes, the spring either unwinds or winds up. A needle is connected to the spring and points to the indicated air temperature.
Thermometer - Wikipedia, the free encyclopedia
Galileo invented the first thermometer in the late 1600s. The exact year is not known, but historians estimate that it was in 1593. He was a famous Italian Mathematician and Scientist whose inventions and mathematical theories are still in use today. The basic principle behind a thermometer, the expansion of air by heat and contraction by cold, was know many hundreds of years earlier. As far back as 300 B.C. experiments of Philo of Byzantium illustrated this principle. Along with Galileo, several other scientists developed better and more accurate thermometers. They were Marin Mersenne, Otto Von Guericke, Robert Boyle, Christian Huygens and Sir Isaac Newton.
This thermometer worked maybe once, the first time I ever used it.
Evolution of the Thermometer A thermometer is a device that gauges temperature by measuring a temperature-dependent property, such as the expansion of a liquid in a sealed tube. The Greco-Roman physician Galen (c. 129-c. 199) was among the first thinkers to envision a scale for measuring temperature, but development of a practical temperature-measuring device the thermoscope did not occur until the sixteenth century. The great physicist Galileo Galilei (1564-1642) may have invented the thermoscope; certainly he constructed one. Galileo s thermoscope consisted of a long glass tube planted in a container of liquid. Prior to inserting the tube into the liquid which was usually colored water, though Galileo s thermoscope used wine as much air as possible was removed from the tube. This created a vacuum (an area devoid of matter, including air), and as a result of pressure differences between the liquid and the interior of the thermoscope tube, some of the liquid went into the tube. But the liquid was not the thermometric medium that is, the substance whose temperature- dependent property changes were measured by the thermoscope. (Mercury, for instance, is the thermometric medium in many thermometers today; however, due to the toxic quality of mercury, an effort is underway to remove mercury thermometers from U.S. schools.) Instead, the air was the medium whose changes the thermoscope measured: when it was warm, the air expanded, pushing down on the liquid; and when the air cooled, it contracted, allowing the liquid to rise. EARLY THERMOMETERS: THE SEARCH FOR A TEMPERATURE SCALE. The first true thermometer, built by Ferdinand II, Grand Duke of Tuscany (1610-1670) in 1641, used alcohol sealed in glass. The latter was marked with a temperature scale containing 50 units, but did not designate a value for zero. In 1664, English physicist Robert Hooke (1635-1703) created a thermometer with a scale divided into units equal to about 1/500 of the volume of the thermometric medium. For the zero point, Hooke chose the temperature at which water freezes, thus establishing a standard still used today in the Fahrenheit and Celsius scales. Olaus Roemer (1644-1710), a Danish astronomer, introduced another important standard. Roemer s thermometer, built in 1702, was based not on one but two fixed points, which he designated as the temperature of snow or crushed ice on the one hand, and the boiling point of water on the other. As with Hooke s use of the freezing point, Roemer s idea of designating the freezing and boiling points of water as the two parameters for temperature measurements has remained in use ever since. 1