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Current time:0:00Total duration:3:52

Video transcript

(jazzy piano) - [Dr. Zucker] We're in downtown Chicago, standing across the street from the Reliance Building. Although it's much smaller than most of the buildings surrounding it, It was a skyscraper in its day and one of the great examples of the Chicago School of Architecture. The building was designed by Burnham and Root, who had already established themselves as one of the most important firms of the building boom that took place in Chicago after the great fire of the early 1870s. - [Dr. Harris] This employed a kind of technology using steel that allowed architects to build much taller buildings than had ever been possible before. In the last half of the 19th century, there were new processes for producing steel that allowed it to be made much more easily and much more cheaply. - [Dr. Zucker] Steel is principally iron. Iron had been used in the 19th century as a structural material, but it had been used largely for greenhouses than for exposition spaces and for bridges. Steel has tremendous tensile strength, and by the end of the 19th century, architects realized that they could use steel to build an interior structure rather than relying on a weight bearing wall, that is, an exterior wall that was a stack of stones or bricks. - [Dr. Harris] And the steel skeleton is on the interior and not visible from the exterior. - [Dr. Zucker] And that allowed for something absolutely new, that the walls could be opened up and the surface could become largely made of glass. - [Dr. Harris] If you're building a building out of brick or stone, if you have a tall building, you have to make the walls thick in order to support the stories above. Once you have a steel frame, that's no longer necessary, those thick walls disappear and you can open up the walls to windows and allow in a lot of natural light. - [Dr. Zucker] It meant that natural light could illuminate a much larger section of the interior and there would be less reliance on interior gas lanterns or later electricity, which meant it was less expensive. This building in particular is such a great example of the architects understanding what was now possible and one of the earliest uses of what we call the curtain wall. In this case, the vertical steel members that support the building have little shelves that come off the front at each story. And so each story of terracotta and glass that we're seeing is an individual unit supported by the shelf immediately below it. - [Dr. Harris] And so you have a situation very different than older brick or stone buildings where the floor below is supporting the floor above. - [Dr. Zucker] Looking at the exterior of the Reliance Building, we're confronted by a surface that is almost all windows and in between this fine terracotta decoration. - [Dr. Harris] Now, that terracotta was also a new material for architecture. It's one that could be mass produced, that was lightweight, that you could add fine, decorative elements to like we see here, these gothic-inspired tracery decorations. And if one of the tiles broke, you could easily replace it. The bottom story is taller than the stories above. - [Dr. Zucker] It's double height. - [Dr. Zucker] And this gives the building a sense of weight and solidity at the bottom. - [Dr. Zucker] Right, there's still a kind of classicism here. We have a double-height base, we have the shaft of the building rising up to be stopped by the shadow of the corners at the top. It may be a little bit difficult to recall the modernity of this building when it was first constructed, but it's use of glass, it's sense of delicacy, it's linear quality, the speed with which it was constructed, and the fact that it was one of the first electrified buildings in Chicago, all would've made this building attractive and an expression of the advances of the Chicago School of Architecture. - [Dr. Harris] This was an expression of the modern world, of modern Chicago. (jazzy piano)