GALILEO GALILEI GLASS
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.


Galileo Galilei did make significant contributions to the field of instrumentation
including the invention of the thermoscope, which was an early version of the modern thermometer.
In 1603, Galileo Galilei made an important discovery related to temperature measurement. He used a small glass flask, about the size of a hen’s egg, and warmed it in his hands.
Galileo then placed the flask’s mouth in a vessel containing water and observed that as he removed his hands from the flask, the water in the flask’s neck rose above the level of the water in the vessel.
This principle formed the basis for the invention of the thermoscope, an early type of thermometer that Galileo used to estimate changes in temperature.

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.