Galileo Thermometer

The principle of this thermometer was discovered by Galileo Galilei: Suspended in the liquid inside the cylinder are a number of weights which are attached to sealed glass bulbs. As the liquid in the cylinder changes temperature, its density changes and the bulbs rise or fall to a position where their density is either equal to that of the surrounding liquid or until they bounce against other bulbs.

The bulbs differ in density by a very small amount and are ordered in a way that the least dense is at the top and densest at the bottom so that they form a temperature scale. The temperature can be read from an engraved metal disc on each bulb.

This Galileo Thermometer is specifically made with a range of 18ºC-24ºC and an accuracy within 1ºC. Most other thermometers of this kind only show the temperature in 2ºC steps.

This is a beautiful instrument and a great gift for science geeks or as a desk ornament in a home office.