This was a fun project that I have had on the books for years. The Galileo Thermometer (or thermoscope) was invented in 1597 by the Italian scientist Galileo Galilei. The glass tube is filled with water. The smaller glass spheres are filled with liquids of different densities. As the temperature of the water changes, the density of the water also changes. As a result, the various glass spheres rise or sink depending on the temperature/density of the liquid within them. The lowest free floating sphere corresponds to the current temperature (equilibrium point). The plan for this project comes from Wood Magazine (October 2003). The parts were cut on a scroll saw and final sanded on my oscillating spindle sander. The wood is cherry. It is finished with Watco cherry oil, two coats of satin Arm-R-Seal and clear Briwax.