- Candela began building thin shell structures not for clients but as full scale experiments. Although he constructed some cylindrical forms, Candela working intensely with hyperbolic paraboloids, or hypars. Eschewing the trend toward reliance on complex mathematics, Candela developed forms where stresses could be determined with simple equations. A form Candela called “umbrellas,” created by joining four straight edge hypars, were an efficient way to cover large spaces such as markets and warehouses. His construction of the Cosmic Rays Laboratory utilized hypars to add stiffness and minimize material thickness, and received international acclaim.