Sir James Doille, a Scot at Oxford University, invented the vacuum insulation cup in 1893. He put one bottle in the other and then pulled the air out of the gap in the middle of the two bottles. Because the vacuum does not transmit heat, the hot or cold water in the Thermos Cup stays at its original temperature for a long time.
By the 1950s, the sales of the Thermos Cup had peaked, and family picnics, seaside hikes and camping in the wild would carry a Thermos cup during this period.