Did you mean: Heinrich Daniel Rühmkorf
Heinrich Daniel Ruhmkorff was a German instrument maker who commercialised the induction coil.
Ruhmkorff was born in Hanover. He changed the "ü" to "u" in his name when living abroad. After an apprenticeship with a German mechanic, he moved to... Wikipedia
Born: January 15, 1803, Kingdom of Hanover
Died: December 20, 1877 (age 74 years), Paris, France
Nationality: German
Award: Volta Prize (1858)