Double revolution staircase - the pre-cut card

THE STAIRCASE WITH DOUBLE REVOLUTION

"One of the most curious and remarkable things in the house is the staircase, made in such a way that one person can go up and another go down without them meeting, although they see each other. Memoirs of Mademoiselle de Montpensier, 17th century. Since the 16th century, it has attracted all eyes upon entering the dungeon and exerted the same fascination on visitors: the double revolution staircase of Chambord is in itself a true monument...

Unlike the majority of staircases, built into the masonry or placed as projections from the facade of the buildings, the double staircase of Chambord is placed in the center of the entire building, at the junction of the four large rooms forming a Greek cross. Everything is ordered with it; everything is ordered around it. It is made up of a hollow and openwork central core (pierced with windows) around which two flights of helical steps wind absolutely twinned. It benefits from a lateral lighting thanks to the large bays which open the cage, and serves the main floors of the keep up to the terraces.

From there, it is surmounted by the highest tower of the castle, the lantern-tower, which contains a narrow spiral staircase, and bears at the top of the building the fleur-de-lis, symbol of the kings of France. The mathematical perfection with which it was ordered, its exceptional central position in the building, and the staging it provides are all arguments in favor of Leonardo da Vinci's participation in the Chambord project. The Italian master, invited to stay with King Francis I as an engineer, painter and architect, may indeed have suggested the introduction of a staircase with double flights as he liked to draw in his famous notebooks...