Thermometers

Appears in
Oxford Companion to Food

By Alan Davidson

Published 2014

  • About

Thermometers measuring temperature, are found in some domestic kitchens and not in others; but are virtually omnipresent in large professional kitchens and food-processing establishments.

All thermometers of conventional design are descended from a device invented by the Italian scientist Galileo in 1592, and now known as a thermoscope. It was a narrow glass tube with a bulb at the bottom. This was filled with water, and the top was left open. If the temperature of the surroundings rose the water would expand, causing its level in the tube to rise. The amount of expansion was tiny, but the change in level was amplified by the fact that the bulb was much larger in diameter than the tube.