The carefully weighted glass globes in this Galileo barometer are suspended in a liquid-filled tube, where they sedately sink or float as the surrounding air gets cooler or warmer. Anne has a BS in Chemistry from the University of Wisconsin, Oshkosh, and an MA in Secondary Education and Teaching from Viterbo University. The individual floats rise or fall in proportion to their respective density and the density of the surrounding liquid as the temperature changes. Although Johan Wolfgang von Goethe is sometimes credited with its invention, one was found in his bedroom after his death, there is evidence that the Moors used similar instruments during the 8th century. This desk instrument combines centuries-old principles to provide meteorological information at a glance: Galileo Galilei’s discovery that the relative density of liquids varies according to temperature provides the basis for the thermometer of floating glass globes; and Admiral Robert Fitzroy’s observations aboard HMS Beagle (during Charles Darwin’s famous voyage) allows weather changes to be predicted with the appearance of streaks, cloudiness, flakes and crystals in a special combination of liquids known as the ‘Storm Glass’.

This model includes a 'storm bottle' type indicator of changes in barometric pressure - useful for forecasting the weather. Using a beaker of water is great for a classroom demonstration because the temperature change between the air and the water makes for a dramatic show.

MAKE A HOUSE A HOME: Lily's Home offers beautifully designed clocks, dishware, garden decorations, and more to add a touch of style to any home. You can change your choices at any time by visiting Cookie preferences, as described in the Cookie notice. Under normal conditions, the orbs will settle into two groupings toward the top and bottom of the glass column as shown to the left. The blue and yellow bubbles (60 and 65 degrees, respectively) are calibrated so that they have higher densities than the water at this temperature, so they sink.

IMPORTANT INFORMATION ABOUT THIS PRODUCT: Your sealed Galileo thermometer is filled with a common mineral-based, ozone friendly solvent (paraffin oil) to prevent bacterial growth. Anne has been teaching high school chemistry for over 20 years and is passionate about providing accessible and educational chemistry content. Since the green bubble is calibrated to represent 70 degrees, the same temperature as the water, it sinks slightly so that it is floating just below the purple and red bubbles -- thereby indicating the room's temperature!I got a bit confused filling the barometer as the instructions implied you only need one syringe full (5ml) of coloured water; I put in nearly 30ml, and now it looks like the pictures. Keep in mind that anyone can view public collections - they may also appear in recommendations and other places. Whether you're looking for a perfect gift to spruce up your friend's garden, or if you need a housewarming present, Lily's Home has something for everyone! Whether you're looking for a statement piece for your living room or looking for a way to add more color to your garden, Lily's Home has just what you're looking for! While the ball underneath it, marked and adjusted for 76 degrees will be denser than the tube liquid and will sink.