Glass to let in more like an interior spaces. This class is an hour and a half. Professor leslie lets get started. Good afternoon to everyone and our expanded classroom today. I want to start quickly with where we are in the course and how this intersects with American History in particular. We have been looking at the history of Building Construction in the west, and we have gotten to the point where we have it developed still amount a fair amount of building structures. We have a couple of new materials we are working with iron and also glass. Finally, we have this conception that we talked about last week from the french theorist who is thinking about iron and iron framing in particular, realizing that late in his career that there is a possibility of having a metal frame that is self structured with a shrill around its meet of masonry that may be selfsupporting. With a shell around it made of mtetal masonry. We wont see how that is developed in a particular place in a particularly