john ochsendorf is a professor at the massachusetts institute of technology and curator of the exhibit. he's dazzled by the marriage of beaut and function in guastavino's work. >> this particular staircase goes up for about 10 stories. this is absolutely awe-inspiring as a work of technol but also as a work of art. you know, i'm an engineer, but i struggle to explain how this stands up. >> reporter: the guastavinos were spanish immigrants who brought centuries-old mediterranean techniques to the united states in the late 1800s. they used the technique called thin-tile vaulting to create a signature and patented style. it was inexpensive, light weight, and strong. >> the mortar would set enough to hold the weight of a single tile. >> reporter: in all, their domes, arches, and vaulted ceilings grace more than 250 buildings in the new york city, like the ellis island registry room, and theica he'deral of st. john the divine in harlem. >> if anyone finds a guastavino billion i do not know about, i will buy you lunch. >> john ochsendorf has been on a safenger hunt for these sites for years,