This is the hanging thermometer based upon the temperature/density observations that Galileo used to create his original. A liquid parrafin-filled glass cylinder suspends five handblown glass balls filled with differing amounts of colored oil. Marked with a metal tab that indicates an incremental range of temperatures between 64° F and 80° F, each ball rises or falls as the surrounding air warms or cools—the lowest ball at the top indicates the current temperature within 3 1/2° F. Optimal accuracy when kept out of direct sunlight. Built-in hook hangs indoors or outdoors. 14" H.