it may shock you to find out alderman are so enthralled to the bricklayers union, but this is the way chicago has always worked. you can see the code's impact almost immediately. adler and sullivan designed the stock exchange, first to be permitted under the new code. they tried to play the game of the bay windows. bringing in a borrowed light from the street. but they are forced to space them so widely apart that they have to come up with another way to bring light into the building in between. here you see some early examples of what would become to known as the chicago window. a piece of glass and iron ore framing that expands as far as possible to fill the void of the column bay. it has a fixed, six foot by six foot panel that is fixed glass then a double hung windows on either side for ventilation. [captioning performed by the national captioning institute, which is responsible for its caption content and accuracy. visit ncicap.org] [captions copyright national cable satellite corp. 2015]

unions. the bricklayers in chicago in 1890's are very well-connected. so connected, in fact, that even as these curtain wall buildings are being permitted, they get the alderman of chicago to pass a new set of requirements in the building code. that require all exterior walls right -- this is loaded terminology -- the fisher building gets rid of walls. here is a code element that requires exterior walls to be a minimum of 12 inches of brick. -- 12 inches thick. it also requires any terra-cotta used for fireproofing to be a minimum of eight inches thick. well, how many of you have laid a brick before? how wide is a brick? eight inches by four inches. these dimensions are not coincidental. these are bricklayers and the brick industry fighting back, saying that if you're going to use these new buildings, you will not get the benefit out of them that you have for the past few years. there is a section that has less to do with the bricklayers and more to do with common sense the double span bay windows featured on the reliance in particular get restricted bo

it may shock you to find out alderman or so enthralled to the bricklayers union but this is the way chicago has always worked. you can see the code impact almost immediately. amber and sullivan -- adler and sullivan designed the stock exchange, first to be permitted under the new code. they tried to play the game of the bay windows. bringing in a borrowed light from the street. but they are forced to space them so widely apart that they have to come up with another way to bring a light into the building in between. here you see some early examples of what would become to known as the chicago window. a piece of glass and iron ore would framing that expands as far as possible to fill the void of the column bay. it has a fixed, six foot by six foot panel that is fixed glass, adler and sullivan play around with this and it becomes the formula for the classic chicago frame that among other things is the essential recipe for louis sullivan's buildings and now target, where the glass actually pushes against the limits of the still structure, the cast iron structure, in some parts behind it. whatev