Galileo Thermometers
by adminGalileo Thermometers are a classic and gorgeous way to keep track of the temperature.
The original concept behind the Galileo thermometer was originally conceived by (duh) Galileo. However, there is no evidence that he actually built one. But they still bear his name today.
The concept is simple, but the execution is difficult. Galileo thermometers work because the density of liquids change as they get hot or cold, much like most other matter. Each of the balls in the liquid cylinder has a very carefully measured mass so that they will float when the liquid is colder than a fixed temperature (and is more dense than the ball) and sink when the liquid is colder than a fixed temperature. Each ball has a different mass and so will float or sink depending on the temperature of the liquid.
So how do you read a Galileo Thermometer? Just take a look at the temperature tag on the lowest floating ball. That is your temperature. If there is a ball that is floating in the middle of the tube, then the temperature is between the lowest floating ball and the ball floating in the middle of the tube.
Galileo thermometers are lovely, but they do have limitations. They only work for indoor temperatures, and then only in the range for a reasonably heated or air-conditioned room. The temperature range is usually 68 to 84 degrees F.
They are also glass, and so are fragile. At the Spectrum store we had the joy of having one of these units break. The liquid inside is a very smelly mineral spirit of some kind. It also turned an interesting shade of pink when it leaked into the bag the thermometer was kept in.
The final disadvantage to Galileo Thermometers is that they are not very precise. While most thermometers give you at least a degree of accuracy, most Galileo thermometers will have up to 4 degrees difference between the floating balls, and even the best of the, such as the 21″ model we sell with 10 temperature balls only has accuracy to within 2 degrees.
But you don’t buy a Galileo Thermometer for the accuracy. You buy it because it looks great, and it is functional as well!
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