Prism Glass

I found a bit of information on prism glass and thought I would share it.

Before electric lighting, around 1900, prism glass was widely used as an architectural glass to redirect sunlight to interior spaces. It uses refraction through a faceted glass to bounce light in many directions.



Penn Station used prism glass to create its bright interior. Unfortunately, it doesn't exist anymore, but you might remember it from history class.



Prism glass was used widely in ship and boat applications before architecture, and used in sidewalk or vault blocks like at the Insurance building down the street (the sunken purple glass blocks). Later, tiles were also developed, which would have been what our building most likely used, laced into a paned window.

Here is a top and side view of a vault prism block manufactured in Montréal.