How did the growth of the middle class affect the public relations industry?

On the ground floor aisles were placed to the left and right of the nave, and were open to pedestrian traffic, hence they were called ambulatories. Above each ambulatory was a triforium, a series of arches lit by windows kept out of sight from below. At the top was the clerestory, a series of windows that allowed light to come streaming through. Shortly after construction, the builders decided that the unfiltered light was too bright for the inside of a church, and the glass was stained so that the church was filled with various colors. Hence a new art form, the art of stained glass windows, was born.