“I have seen in my youth that whoever knew the way to make the layout of the aforementioned vis Saint Gilles (Saint Gilles’ winding stairway) and was quite acquainted with it was highly esteemed among the workers”
Philibert Delorme – 1567, p 123 reverse side –
Link for the complete research :
http://www.arct.cam.ac.uk/research/researchgroups/sustainablebuilding/traditional-building-construction-research/ICCH