Thermos comes from the Greek word “therme” which means heat. The first thermos was called the Dewar flask in honor of Sir James Dewar who invented it in order to supplement his research of liquefying gases. The thermos insulates liquids and sometimes solids keeping them at a constant temperature. This is achieved by having internal reflective surfaces, which prevent heat radiation from leaving the flask. Glass often lines the outside of the inner flask because glass does not conduct heat well. Between the inner and outer shell of the flask is a vacuum. In this way, heat loss through convection is prevented. The thermos is used worldwide today. Many schoolchildren use it to carry hot or cold drinks to lunch. Even Lieutenant Robert E Peary took it on his expedition to the South Pole. The Wright Brothers took it on their first airplane flight. The thermos has become an important way to store liquids only surpassed by the invention of refrigeration.

*Picture from Encarta Encyclopedia