Innovator of Lighthouse Illumination
Early Life and Education
Nils Gustaf Dalén (1869–1937) was a Swedish physicist and engineer, born in Stenstorp, Skaraborg, on November 30, 1869. The son of a farmer, he initially pursued agricultural studies but was encouraged by the inventor Gustaf de Laval to pursue engineering. Dalén enrolled in the Chalmers Institute at Gothenburg and graduated in 1896.
Dalén’s inventive nature was evident from his early years, having built a threshing machine and a device to measure butterfat content on his family’s farm. After his formal studies, he developed a hot-air turbine, air compressors, and various dairy-related devices, including a milking machine and a pasteurization apparatus.
Inventions and Contributions to Lighthouse Technology
In 1902, Dalén introduced acetylene welding to Sweden and co-founded Dalén & Celsing while also working with Svenska Carbid & Acetylen, which later became AGA. Responding to the Pilotage Service’s call in 1905 for efficient lighting for lighthouses, he invented a gas-saving flashing apparatus that used only a tenth of the acetylene gas of previous models. In 1907, he developed the sun valve, an automatic sensor that turned lighthouse lights on at dusk and off at dawn.
His inventions revolutionized maritime navigation by allowing lighthouses to operate automatically for extended periods. Dalén also created safer methods for storing and handling acetylene, including a porous storage cylinder and a balanced gas-air mixer. In 1906, he developed the AGA compound to minimize gas explosion risks.
Dalén became president of AGA in 1909. His innovations made AGA lighthouses a global success.
Injury and Continued Innovation
In 1912, during a safety test, a gas cylinder explosion caused him to lose his eyesight. Despite his injuries, he remained president of AGA for 25 years, guiding its global growth.
Dalén was awarded the Nobel Prize in Physics in 1912 for his self-operating regulators and their application in lighthouse and buoy lighting. His citation recognized the practical significance of his inventions.
After his accident, Dalén invented the AGA cooker, a coal-fueled stove that maintained heat for 24 hours with minimal fuel. It was launched in 1929 and became a major export success.
Recognition and Legacy
Throughout his career, Dalén held nearly 100 patents. He was elected to the Swedish Royal Academy of Sciences (1913), received an honorary doctorate from Lund University (1918), and became a member of the Academy of Science and Engineering (1919). He also received the Nordstjärne Order, the Wasa Order, the Morehead Medal, and served in economic and municipal councils.
Dalén married Elma Persson in 1901. They had four children. His son Gunnar later became the Director of AGA, while his other son, Anders, pursued medicine. His brother Albin was a professor of ophthalmology.
Nils Gustaf Dalén died on December 9, 1937, at his home, Villa Ekbacken, in Lidingö. The villa, built in 1912 near the AGA plant, is now the residence of Canada’s ambassador to Sweden.
In 1954, AGA celebrated its 50th anniversary. That same year, a film titled Victory in the Darkness, based on Erik Wästberg’s biography, highlighted Dalén’s life and legacy.