The AGA cooker is a heat storage stove and cooker, which works on the principle that a heavy frame made from cast iron components can absorb heat from a relatively low-intensity but continuously-burning source, and the accumulated heat can then be used when needed for cooking. Originally heated by slow-burning coal, the Aga cooker was invented in 1922 by the Nobel Prize-winning Swedish physicist Gustaf Dalén (1869–1937), who was employed first as the chief engineer of the Swedish AGA company (Swedish: Aktiebolaget Svenska Gasaccumolator, English: Joint stock company Swedish Gas Accumulator).