Thermos

There are a huge number of thermoses. They can be divided into two large categories: household and professional, with a volume of more than 5 liters. Household ones are the most common and the most diverse: the differences in color, material, and shape are simply colossal.

In 1881, a vessel with vacuum walls was invented: two glasses with rarefied air between them. Two years later, this design was improved by James Dewar. He was faced with the task of preserving liquid oxygen, which evaporated very quickly, and then he reduced the neck of the vessel with vacuum walls, creating a kind of flask. Both walls on the evacuated side were coated with a thin mirror-like layer of silver, which better reflected heat. The flask itself was placed on springs in a metal case, which prevented light rays from entering it. This vessel was called the “Dewar flask”.

It has come down to us practically in this form. The name “ thermos ” was first included in the name of the company producing it, but soon became a common noun for all products of this type. Modern thermoses have virtually minimal heat loss and an ergonomic body. Many thermoses larger than a liter are equipped with a pump for ease of use. When choosing a thermos, do not forget to take into account the consistency of the product: there are special thermoses for thick food or thermoses for coffee /tea.