A Thermometer Based on a Principle Discovered by Galileo Galilei (1564-1642) Galileo Galiliei,the pioneer of modern physics and astronomy, never could have imagined that the remarkable thermometer he invented four centuries ago would become one of the most attactive, intriguing, eye-catching gift items today. The Galileo Thermometer is a unique looking cylinder filled with colorful Glass spheres that float. They measure the correct themperature based on a fascinating scientific principal. What Galileo discovered is that spheres of different weights would rise or fall according to the temperature. Due to the fact that the liquids in the cylinder contract slightly at higher tempuratures, the spheres rise and fall accordingly. In the Galileo Thermometer, the lowest floating sphere in the upper part of the cylinder tells the correct temperature. Tolook at a glass Galileo Thermometer is to behold not only an instrument that tells the precise temperature, but also a work of beauty and art. The uniqueness of this item will challenge you visuallly, pracically and intellectually. The Galileo Thermometer is a conversation piece that leaves a lasting impression. Few other gifts items meld design and concept so effectively.