glass ball Galileo thermometer, barometer in Norwich, Norfolk for sale

glass ball Galileo thermometer, barometer A really pretty decorative piece. Will look lovely on the windowsill. Consists of a sealed glass tube that is filled with water and several floating bubbles. The bubbles are glass spheres filled with a blue coloured liquid mixture. Attached to each bubble is a little metal tag that indicates a temperature. A number and degree symbol are engraved in the tag. The basic idea is that as the temperature of the air outside the thermometer changes, so does the temperature of the water surrounding the bubbles. As the temperature of the water changes, it either expands or contracts, thereby changing its density. So, at any given density, some of the bubbles will float and others will sink. The bubble that sinks the most indicates the approximate current temperature. Fun and pretty!