Delisle scale

1732 Delisle scale

The book of science

Tom Sharp

Joseph-Nicolas Delisle thermometry Delisle scale

Delisle scale

Peter the Great invited Joseph-Nicolas Delisle to create and run a school of astronomy in Saint Petersburg where Delisle created a scale whose zero point is at the temperature of boiling water and that increases in fine degrees as temperatures get cooler, to one hundred at the freezing point of water.

Backwards

The original centigrade scale went backwards one hundred degrees from the boiling point to the freezing point of water. The original Delisle scale went backwards one hundred degrees from the boiling point to the freezing point of water. Josias Weitbrecht recalibrated the Delisle scale but kept it going backwards one hundred fifty degrees from the boiling point to the freezing point of water. Weitbrecht then sent this recalibrated scale to Anders Celsius in 1738. In 1742, Celsius created the centigrade scale, with one hundred degrees from the boiling point to the freezing point of water.

2400 or more graduations

So many degrees, each divided into fine graduations, 2400 or 2700 of them, with absolute zero at 559.73 °De; however, no word as to what kind of water should be used or what the barometric pressure, which varies with the weather.

The scientific contribution of Anders Celsius was not creating the scale, but in establishing that the freezing point of water is independent of barometric pressure, and that the boiling point of water at a standard barometric pressure could be calculated from a given barometric pressure.

See also in The book of science:

Readings on wikipedia: