The world’s first thermometer
A Gaileo Galilei glass is a thermometer and measures temperature.
In 1593, astronomer, physicist, engineer and ‘father of advanced science’ Galileo Galilei discovered that the volume of a liquid changes when its temperature changes. Galileo, with his newly discovered fascinating knowledge, Galileo Galilei created the glass, and was the first to invent a tool that could measure temperature variations. In the following years, the thermometer was further developed by Galileo, Santorio Santorio and Galileo’s friend Gianfrancesco Sagredo, and Gabriel Fahrenheit and Anders Celcius invented the two temperature scales that today can both be read on the Inca Living Galileo Galilei glass.
A first-hand account of the discovery
In 1603, the Italian physicist and mathematician Benedetto Castelli described Galileo Galilei’s discovery of the thermocouple as follows
“Galileo took a small glass flask about the size of a small hen’s egg, with a neck about two spans long and as fine as a straw of wheat, warmed the flask well in his hands, and then turned its mouth into a vessel placed below, in which was a little water. When he took the heat of his hands from the flask, the water immediately began to rise in the neck and rose to more than a span above the water in the vessel. Galileo made use of this effect to construct an instrument to estimate heat and cold.”
The Galileo Galieli glass is an ever-changing thermometer
The appearance of the glass changes with changes in temperature.
The Galileo Galilei glass contains four precisely calibrated glass spheres floating in a liquid. On each glass ball is a small metal plate with a temperature indication. As the temperature in the room rises, the glass balls fall. As the temperature in the room drops, the glass balls rise. For example, the 18-degree glass ball will drop when the temperature in the room gets above 19 degrees. Conversely, the 18-degree glass ball will rise when the temperature in the room falls below 17 degrees.
If a glass ball floats in the middle of the cylinder, the temperature is between the number on it and the number on the lowest floating glass ball at the top of the cylinder.
If all glass balls float at the top of the cylinder, the temperature is lower than the number on the lowest floating glass ball.
If all glass balls float at the bottom of the cylinder, the temperature is higher than the number on the highest floating glass ball.