Ognjeslav Kostović Stepanović
He is credited with creating "arbonite" (i.e. plywood), the first plastic in the world. Kostović patented the technology of the production of arbonite in the USA on 4 September 1906. In the early 1880s he designed and attempted to construct a dirigible (airship), about 20 years before Ferdinand von Zeppelin. His flight vehicle was destroyed in a fire and it was never tested in the air. He also developed and constructed a large gasoline engine for his dirigible. In 1879 he demonstrated his flying models of a helicopter, aircraft and ornithopter, while in 1881 approached the building of an aircraft. In the catalog of aeronautical exhibition 1911 and in the article of G.V. Piotrovski it is said, that Kostović actually constructed a flight vehicle. The same was also said in A. Ewald's report in the Russian technical society on 12 March 1883.
When he died in December 1916 in Saint Petersburg, the press reported that "a brilliant inventor and scientist has disappeared, a man who has, for many reasons, deserved that future generations remember his unusual destiny and scientific achievements".
- The creation of dirigibles (in Russian)