Terra-Cottology, Part 3: Close-Up of the Exterior of the Railway Exchange Building, the Loop, Chicago, Illinois, USA (1904)
Looking at a portion of the entranceway of the building's eastern, lake-facing, South Michigan Avenue elevation.
So here at last we have a close-in view of the white-glazed terra-cotta sections manufactured from Pennsylvanian (Upper Carboniferous) underclays and shales by Chicago's own Northwestern works.
Like ashlar blocks, they are set between joints of mortar, but unlike them they're fireproof, remarkably light in weight, and secured at the back with metal fasteners. And because they could be molded in exquisite detail by Northwestern's staff of master craftsmen, the cladding units embodied even the wildest flights of a designer's fancy.
The light weight ensured that terra-cotta sections were easier to manipulate and less costly to ship. And, as noted in Part 1, they could be cleaned much more easily—a fact that made the erection of white skyscrapers in the Age of Bituminous Coal Burning much less of a folly to propose to image-conscious developers.
But while turn-of-the-century architects had all sorts of reasons for preferring terra-cotta to rock, the fact remains that no material mounted on a building exterior in a continental climate can be expected to survive the onslaught of precipitation, air pollution, and temperature extremes for more than a few fleeting decades.
This point can be easily ascertained if you scrutinize this image under high magnification. You'll find plenty of places where the very thin layer of ceramic glaze has chipped or spalled away to reveal the bisque, the fired-clay base material.
For more on this site, see my book Chicago in Stone and Clay, described at www.cornellpress.cornell.edu/book/9781501765063/chicago-i...
And to see the other photos and descriptions of this series, visit my Terra-Cottology album.
Terra-Cottology, Part 3: Close-Up of the Exterior of the Railway Exchange Building, the Loop, Chicago, Illinois, USA (1904)
Looking at a portion of the entranceway of the building's eastern, lake-facing, South Michigan Avenue elevation.
So here at last we have a close-in view of the white-glazed terra-cotta sections manufactured from Pennsylvanian (Upper Carboniferous) underclays and shales by Chicago's own Northwestern works.
Like ashlar blocks, they are set between joints of mortar, but unlike them they're fireproof, remarkably light in weight, and secured at the back with metal fasteners. And because they could be molded in exquisite detail by Northwestern's staff of master craftsmen, the cladding units embodied even the wildest flights of a designer's fancy.
The light weight ensured that terra-cotta sections were easier to manipulate and less costly to ship. And, as noted in Part 1, they could be cleaned much more easily—a fact that made the erection of white skyscrapers in the Age of Bituminous Coal Burning much less of a folly to propose to image-conscious developers.
But while turn-of-the-century architects had all sorts of reasons for preferring terra-cotta to rock, the fact remains that no material mounted on a building exterior in a continental climate can be expected to survive the onslaught of precipitation, air pollution, and temperature extremes for more than a few fleeting decades.
This point can be easily ascertained if you scrutinize this image under high magnification. You'll find plenty of places where the very thin layer of ceramic glaze has chipped or spalled away to reveal the bisque, the fired-clay base material.
For more on this site, see my book Chicago in Stone and Clay, described at www.cornellpress.cornell.edu/book/9781501765063/chicago-i...
And to see the other photos and descriptions of this series, visit my Terra-Cottology album.