I have found this interesting video about extravagant furniture inventions from the 18th century. It´s a secretary cabinet from the Abraham (1711–1793) and David Roentgen’s (1743–1807) workshop with hidden features. It was used for writing. At the top it has a chiming clock and finely designed marquetry panels. Its elaborated mechanics allow hidden doors and drawers to be opened automatically at the touch of a button. It was owned by King Frederick William II. This unique cabinet is remarkable because of its mechanical complexity, ornate decoration and its size.
(This cabinet is from Kunstgewerbemuseum, Staatliche Museen zu Berlin.)
See also a convertible writing desk:
Footage courtesy of VideoART GmbH and Kunstgewerbemuseum, Staatliche Museen zu Berlin.
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