Ambient Weather WS-TB1071305 Galileo Thermometer and Glass Fluid Barometer, 13" The Galileo thermometer consists of a sealed glass tube that is filled with fluid (paraffin oil) and several floating bubbles Attached to each bubble is a little metal tag that indicates a temperature;These metal tags are calibrated counterweights The weight of each tag is slightly different from the others, Sin;e the bubbles are all hand-blown glass, they aren't exactly the same size and shape The weight of each tag is slightly different from the others; Since the bubbles are all hand-blown glass, they aren't exactly the same size and shape The weather prediction device is called a storm glass, It consists of a glass container with a sealed body, half filled with water