The Roentgens’ Berlin Secretary Cabinet was designed and constructed by Abraham (1711–1793) and David Roentgen (1743–1807). The construction started in 1778 and it took a year to be completed since it was crafted by hand. Abraham and David Roentgen were known as master cabinet-makers during the early 1700s into the early 1800s and they made the cabinet for King Frederick William II.
The cabinet contains several hidden compartments and is uniquely remarkable for its beautiful woodwork, mechanical complexity, and sheer size.
The doors and drawers can be opened and moved automatically at the touch of a button—to the music of flute, cymbal, and glockenspiel—as can the entire interior desk area, various secret jewel boxes, and hidden compartments.
Now see how it works and prepare to be amazed.
You can see more extravagant inventions at metmuseum