Antonio Gaudi’s work benefits significantly from this continuity and cooperation among artisan craftsmen.

This is especially the case with Gaudi’s use of the inverted catenary arch, a form essential to potters.

Potters used suspended rope to create a stencil of the size and shape of the kiln they wanted, and then inverted the template and used it as a guide as they built.

The inverted arch had been on the Iberian Peninsula and around the Mediterranean for six thousand years.

Invented in African Nubia and spread throughout the continent, the Nubian inverted arch rotated around its central axis created a vault, a complex shape that migrated out of Africa north and was use for shelter, burial mounds, and kilns.

File:Maqueta tholos Los Millares.Jpg. In Wikipedia. https://commons.wikimedia.org/wiki/File:Maqueta_tholos_Los_Millares.jpg

The outstanding feature of the arch and vault is that they can be built without interior support or shoring. The bricks are laid leaning at a slight slope—the same principle used to build the Cathedral of Saint Mary of the Flower dome.