Cathedral of St. John the Divine interior ca. 1959

The Guastavino Company pushed the limits of traditional tile vaulting further than any previous builders. Guastavino Jr.’s building method for the dome of the Cathedral of St. John the Divine required no support during construction, yet created a highly stable shell only 4.5 inches thick at its crown. The 135-foot span was erected in a mere 15 weeks. Originally intended as a temporary, inexpensive cover for the crossing of the cathedral’s two main axes, the dome remains in place today—a testament to its solid construction.