Yesterday I drove to Dijon with three of my children in tow to do a brief photogrammetric survey of one of the nave bays of Notre-Dame of Dijon. The building has long been part of the story of Gothic structure: it was studied during the Enlightenment for its structural prowess, and transformed, at the hands of Viollet-le-Duc, into a living organism, whose judiciiously arranged skeleton actively countered the thrusts of the vaults. The means of representation, in each case, was the section drawing—drawn not according to accurate survey data, but according to the logic of the argument being presented. The new data will make it possible to see the building as it really is.