RONSDORF,  . a town of Germany, in the Prussian Rhine province, situated on the Morsbach, a small affluent of the Rhine, 18 m . E. of Dusseldorf and 5 M . S. of Elberfeld-Barmen by rail . Pop . (1905) 14,005 . It is the seat of iron, steel and copper industries, besides carrying on extensive manufactures of ribbons, trimmings and silk goods generally . It has also breweries, distilleries and electrical works . Founded in 1737 by the followers of Elias Eller, a religious enthusiast, Ronsdorf received civic rights in 1745• The Ronsdorf sect, the members of which called themselves Zionites, is now extinct .