As the son of a merchant from Turku, in the 1890s John Silén studied economics at various places, including Germany. He then worked as an auditor at the Nordic Union Bank for almost three decades.
Silén was a crew member of the Finnish boat “Heatherbell” that placed third and last in both races of the 12 metres class at the Stockholm Olympic Games in 1912. With only three yachts competing, the crew still took bronze. He was also an avid skater and represented his country at the International Skating Federation Congress in Budapest in 1913. He remained single and is said to have been homosexual. His tombstone was a rock he himself brought from a sailing trip in the Turku archipelago.
Finland