Ernst Gräfenberg Ernst Gräfenberg Ernst Gräfenberg (September 26, 1881 in Adelebsen near Göttingen, Germany – 28 October 1957 in New York City, United States) was a German-born physician (medical doctor) and scientist. He is known for developing the intrauterine device (IUD), and for his studies of the role of the woman's urethra in orgasm. The G-spot is named after him. Gräfenberg studied medicine in Göttingen and Munich, earning his doctorate on 10 March 1905. He began working as a doctor of ophthalmology at the university of Würzburg, but then moved to the Department of Obstetrics and Gynaecology at the University of Kiel,
Ernst Plank Hans and Fritz Schaller, who gave up the production of toys to focus on the optical market. Ernst Plank toy trains are highly collectable in part due to their rarity. The company continued to produce movie projectors for home use, finding a lucrative market in the 1960s and 1970s. The development of video cameras drastically reduced the market especially for Super 8 film. In 1985 production was discontinued. Ernst Plank Ernst Plank was a German manufacturing company. Started in 1866 and named after its founder the company initially built toy steam engines and magic lanterns at Hochfederstrasse 40 in Nuremberg.