A thermometer is a device used to measure temperature. It was invented by Galileo in 1592. The graduation and inclusion of fixed points was added by Sanctorio who used snow and the heat of a candle, dividing the range obtained into degrees. The first sealed thermometer was made by Ferdinand II, the Grand Duke of Tuscany, in 1654. He filled the bulb and part of the tube with alcohol and then melted the glass tip, thereby sealing the tube. In England, Boyle, at the request of the Royal Society, made experiments on thermometers, his lectures on cold being published in 1665. Mercurial thermometers were first employed by the Academia del Climento of Florence in 1657. In 1694 Renaldini suggested the boiling-point of water as the upper limit of the scale. In 1706 Fahrenheit made improvements to the thermometer. In 1714 he made his Fahrenheit
thermometer with three fixed points. He arrived at his zero by taking a mixture of ice water and sal ammoniac; the second point he obtained by mixing ice and water - this point he called 32 degrees, or freezing point, his third mark was blood heat and was obtained by placing the thermometer in the mouth of a healthy man and holding it there until it reached the body temperature. He then divided the distance between the melting point of ice - 32 degrees - and the boiling point of water - 212 degrees - into 180 degree marks. Celsius invented his own scale with the boiling point of water at zero and the freezing point of water at 100 degrees, this scale has now been inverted. Research Thermometer
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Abbreviations
SciTech
Research Thermometer
