Galileo Thermometer (28cm high). Includes 5 temperature bulbs (18 to 26 degrees celsius. Comes in an attractive box.
How does it work? Each bulb floating in the water inside the sealed glass tube has a slightly different counterweight attached with an engraved temperature. The bulbs are also calibrated by adding a certain amount of coloured liquid to them. This ensures each bulb has a slightly different density. Two forces are at work here: the downward pull of gravity and the upward push of buoyancy. When the temperature in the air changes, so too does the temperature of the water surrounding the bulbs, and its density. Some bulbs will float, others will sink. The lowest upper floating glass bulb indicates the temperature. This elegant thermometer has a minimum and maximum temperature reading of 18 and 26.
Teaches Forces: downward pull of gravity and the upward push of buoyancy. Floating and sinking Density and how it is effected by temperature changes