Vaults, Penetrations and Intersections
A: Penetrations by small semi-circular vaults sprung from same level. B: Intersection by small semicircular vault sprung from higher level; groins form wavy line. C: Intersection by narrow pointed vault sprung from same level; groins are plane curves.
A. D. F. Hamlin College Histories of Art History of Architecture (New York, NY: Longmans, Green, and Co., 1915)
Courtesy the private collection of Roy Winkelman