Unused Welsbach No. 4 Inverted Mantle and No. 8 Magnesia Ring in its original cardboard box from Lindsay Light and Chemical Company.

The Welsbach gas mantle is a device made of fibers impregnated with oxides of cerium and thorium, an element that is mildly radioactive. Mantles produce a bright white light when heated with a gas flame; effectively the gaslight equivalent of a filament in an electric lightbulb. Invented in the 1880s by Austrian scientist Carl Auer Von Welsbach (1858-1929), gas mantles were used extensively in street lighting and in gas-powered appliances. The Welsbach gas mantle was the first industrial product to make use of rare earth elements. Welsbach mantels were sewn and then packed into cardboard tubes for shipping and sales. The Lindsay Chemical Company in Chicago took over the Welsbach marketing logo in the early twentieth century and continued the production of mantels compatible with Welsbach products until the mid-1930s.