Potters Guild
It is plausible that the shell secret migrated out of Spain with the exodus that occurs with the defeat of the Moors, and helped initiate the Renaissance––the return of Humanism––when given to the Medici family in response to their patronage of the Potters Guild, which was closely related to sculptors.


Since the time of the Black Pharaohs, the Masonic Order had investigated lines of force in nature and ascertained through experiential knowledge those structures demonstrating “the path of least resistance,” getting the desired result with minimal effort.
From this perspective, the eggshell was the obvious candidate to mimic. Although limited by the strength of the materials at hand, the shell concept dictated how those materials had to be employed.

The catenary curve on pottery chard (2650 BC) was excavated in or near 1925 in Djoser's Pyramid in Saqqara, Egypt.