This beautiful thermometer springs from the discovery by the 17th century scientist Galileo Galilei that the density of liquids varies with temperature.
It was invented almost 400 years ago by students of Galileo.
Carefully weighted glass globes are suspended in a liquid-filled tube, where they sedately sink or float as the surrounding air gets hotter or colder. Temperature is shown by the engraved brass tag on the lowest floating globe.
Inspired by the 100th Monkey Phenomenon of Social Change - the idea that once a certain number of a group start using a new habit, it will be taken up instinctively by all - these 334 gram borosilicate glass coffee cups are stain and odour resistant, reusable, and 100% BPA free.