Johann Adam Hoyer was a clockmaker and master craftsman in Josefstadt (now the 8th district of Vienna) who died in 1838. There are a few known examples of his work still extant, including a flute clock and a miniature wall clock from the Biedermeier era. He is credited with developing a clock that was wound by the creation of hydrogen. Hoyer was one of a few clockmakers in the early 19th century who experimented with hydrogen-powered winding mechanisms. Pasquale Andervalt in Italy c. 1835 was another, and his clock is in the Clockmakers' Company in London.