Guastavino structural tile vaults: the technique was patented in
1885 by Spanish architect & builder Rafael Guastavino, who then
worked with his son after the turn of last century. Examples are found
in several hundred buildings in NYC; there are a thousand installations
in the United States. On the left is Wolfgang's Steakhouse at 4 Park Avenue,
Manhattan.
http://en.wikipedia.org/wiki/Guastavino_tile