Jaquet-Droz automata

The musician

The musician is modelled as a female organ player. The music is not recorded or played by a musical box: the doll plays a genuine, custom-built instrument by pressing the keys with her fingers. Movements of her chest show her "breathing", and she follows her fingers with her head and eyes. The automaton also makes some of the movements that a real player would do, such as balancing the torso.

The draughtsman

The draughtsman is modelled as a young child, and is capable of drawing four different images: a portrait of Louis XV, a royal couple (believed to be Marie Antoinette and Louis XVI), a dog with "Mon toutou" ("my doggy") written beside it, and a scene of Cupid driving a chariot pulled by a butterfly.

The draughtsman works by using a system of cams that code the movements of the hand in two dimensions, plus one to lift the pencil. The automaton also moves on his chair, and he periodically blows on the pencil to remove dust.

The writer

The writer is the most complex of the three automata. Using a system similar to the one used for the draughtsman for each letter, he is able to write any custom text up to 40 letters long (the text is rarely changed; one of the latest instances was in honour of president François Mitterrand when he toured the city). The text is coded on a wheel where characters are selected one by one. He uses a goose feather to write, which he inks from time to time, including a shake of the wrist to prevent ink from spilling. His eyes follow the text being written, and his head moves when he takes some ink. The writer is 70 cm (2 ft 4 in) tall.