In 1889, the city of Seattle burned to the ground. When they rebuilt, they decided to take advantage of the situation and move the “street level” up one floor. The result was a basement level in the downtown area of the city, complete with sidewalks! To allow light into these underground areas, the street level sidewalks were imbedded with glass chunks, tapered at one end to maximize light transfer. Brilliant! They’re called prism lights, and Seattle is not the only city to put them to use. I hear that the purple color is a result of the aging for the manganese that was added to the glass as a stabilizer. These prism lights also look amazing when the “sidewalk vault” underneath is lit at night, so the purple glass glows.
I found this fun 1880’s flyer online about the Brown Brothers Manufacturing Company, which may well have been the producers of the prism lights, but if they were, that means they were shipped all the way from Chicago! Perhaps they were made by one of the other prism glass companies I found listed here.
Wherever they came from, these beautiful and ingenious panels are a treasured part of Seattle’s personality, and an interesting part of its history.