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http://www.brannan.co.uk/thermometers/invention.html
1714 The first mercury thermometer
Gabriel Fahrenheit (1686-1736) was the first person to make a thermometer using mercury. The more predictable expansion of mercury combined with improved glassworking techniques led to a much more accurate thermometer.
Fahrenheit - the first Standard Thermometer Scale
Fahrenheit used the newly discovered fixed points to devise the first standard temperature scale for his thermometer. Fahrenheit divided the freezing and boiling points of water into 180 degrees. 32 was chosen as the the figure for the lower fixed point as this produced a scale that would not fall below zero even when measuring the lowest possible temperatures that he could produce in his laboratory - a mixture of ice, salt and water. It is sometimes suggested that Fahrenheit divided his scale into 100 degrees using blood temperature (incorrectly measured) and the freezing point of water as fixed points - this is not true. The Fahrenheit scale is still in use today.
1731 The Réamur Scale
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°. The Réamur scale is not in use today.
1742 The Celsius Scale
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.
1714 The first mercury thermometer
Gabriel Fahrenheit (1686-1736) was the first person to make a thermometer using mercury. The more predictable expansion of mercury combined with improved glassworking techniques led to a much more accurate thermometer.
Fahrenheit - the first Standard Thermometer Scale
Fahrenheit used the newly discovered fixed points to devise the first standard temperature scale for his thermometer. Fahrenheit divided the freezing and boiling points of water into 180 degrees. 32 was chosen as the the figure for the lower fixed point as this produced a scale that would not fall below zero even when measuring the lowest possible temperatures that he could produce in his laboratory - a mixture of ice, salt and water. It is sometimes suggested that Fahrenheit divided his scale into 100 degrees using blood temperature (incorrectly measured) and the freezing point of water as fixed points - this is not true. The Fahrenheit scale is still in use today.
1731 The Réamur Scale
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°. The Réamur scale is not in use today.
1742 The Celsius Scale
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.