Jens Olsen's World Clock or Verdensur is an advanced astronomical clock which is displayed in Copenhagen City Hall. The mechanical clock consists of 12 movements which together have 15,448 parts and must be wound at least once a week. It was designed and calculated by Jens Olsen who was a skilled locksmith, but later learned the trade of clockmaking. He also took part in the beginning of the clock's construction, but died in 1945, 10 years before the clock was completed. (wikipedia). Mortensen, the author, was a colleague who worked with Olsen and took charge of the completion after Olsen's death. This work provides the detailed technical description of the clock and its workings.



G.K. Hadfield, established in 1966, is a noted dealer in fine antique clocks, rare horological books, and restoration materials based in Cumbria, UK

First edition. Small folio (30 x 21 cm), numerous black and white illustrations throughout, some in text and some full page, red silk endpapers, binder's stamp in gilt on front pastedown; bound by Zaehnsdorf in full red gilt, spine gilt lettered and ruled, gilt motif on upper cover, all edges gilt, housed in red cloth slipcase; an excellent copy; 156pp