It may be due to the quality of the clay, or the lack of clay at all, for making the bricks. I saw a documentary on this just a few months ago aired by our loca

It may be due to the quality of the clay, or the lack of clay at all, for making the bricks. I saw a documentary on this just a few months ago aired by our local PBS station on this very subject. http://ninenet.org/archives/pressroom/st-louis-brick-building-legacy-explored-on-special-hour-long-program-2 http://ninenet.org/archives/pressroom/st-louis-brick-buildin... https://vimeo.com/ondemand/brick https://vimeo.com/ondemand/brick