Monday, December 17, 2012

Ancient Chinese Temperature Measurement

Most people concur, Galileo invented the first documented thermoscope in about 1592. When informally surveyed by me, none of my Chinese friends could tell me how temperature was measured in ancient China so I decided to do some research. Surely a people who can come up with the compass and all manner of astronomical and meteorological equipment had some way of recording temperature, I thought, but I have come up short. It remains a mystery! We don't know what the ancient Greeks or Egyptians did, either, although there is some theoretical, printed matter on thermometers still extant from the Greeks. Philo of Byzantium and Hero of Alexandria knew of the principle 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.

Verbiest's thermometer.
According to a short article in the Geographical Review:
Thermometers and hygroscopes were first introduced into China in the middle of the seventeenth century by Ferdinand Verbiest16 (1623-1688), a disciple of Tycho Brahe (1546-1601). Verbiest entered China in the year 1659. From that year until his death he received numerous favors and honors from the Emperor Kan-Si [sic]. For several years he held the post of President of the Board of Mathematics and Astronomy
What I do know empirically is that it was -8 degrees F this morning in Changchun. We have had more snowfall this year already than I witness cumulatively in the previous two winters. I cannot see out the balcony windows because the condensation has totally occluded them.