Perspective Study of Mazzocchio
"Perspective Study of Mazzocchio" was the name usually given to a sketch made by the  Paolo Uccello, depicting the toroidal structure of a mazzocchio, a type of headgear. The study payed of as a mazzocchio was successfully depicted in the fresco Flood and Waters Subsiding.

In an alternate reality,  had a large print of the study behind his desk in his office. ()

External link
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Earth visual art
Alternate reality