A Chinese drinking bird toy dating back to 1910s~1930s named insatiable birdie is described in Yakov Perelman 's Physics for Entertainment. The book explained the "insatiable" mechanism: "Since the headtube's temperature becomes lower than that of the tail reservoir, this causes a drop in the pressure of the saturated vapours in the head-tube..." It was said in Shanghai, China, that when Albert Einstein and his wife, Elsa, arrived in Shanghai in 1922, they were fascinated by the Chinese "insatiable birdie" toy.