Nils Gustaf Dalén
Born: 30 November 1869, Stenstorp, Sweden
Died: 9 December 1937, Stockholm, Sweden
Affiliation at the time of the award: Swedish Gas-Accumulator Co., Lidingö-Stockholm, Sweden
Prize motivation: "for his invention of automatic regulators for use in conjunction with gas accumulators for illuminating lighthouses and buoys"
Field: applied mechanics, mechanics
Prize share: 1/1
For centuries, lighthouses have made navigation safer. In the 19th century, acetylene gas began to be used to light their beacons. Gustaf Dalén developed a method for emitting short flashes of light, thereby reducing gas consumption. In 1907 he invented a regulating valve based on the difference in expansion between black and white metal rods. This "solar valve" could extinguish beacons during daytime, saving more money.