The Dalén Mixer In light buoys and small lighthouses an open acetylene flame provides a strong enough light. But to obtain the stronger light required in open-sea lighthouses a mantle must be used. Gustaf Dalén’s so-called Dalén mixer from 1907 provides the right mixture of air and acetylene to keep the mantle burning incandescently with a strong light. With the pressure from the acetylene as the sole source of energy the Dalén mixer can also power a rotating lens system. This makes the light even stronger and the lighthouse can be given the desired characteristic. The Dalén mixer eventually came to be used in a number of other products.