Overview

At the start of the seventeenth century, there was no way to measure heat. Although it was known that air expanded as it was heated, and compressed as it was cooled, no one had thought to assign numbers to the degrees of hot and cold. Cornelis Drebbel (1572-1633) was one of a small group of European practical and learned men who worked on developing air thermometers that included numerical scales. Their inventions and innovations illustrate the seventeenth-century trend toward quantifying natural phenomena. But Drebbel's greatest invention was the thermostat.

Background

Drebbel began his career in Holland as an engraver, but turned to mechanical invention in 1598. He had a special interest in how temperature and pressure cause a volume of air to vary. For example, Drebbel observed that heating air and water causes them to expand, whereas cooling compresses them...