In 1935, Boston architect Chester Lindsay Churchill completed the Mapparium, a three-story spherical globe room with a map of the world made from stained glass:
Churchill purchased large glass panels from the Hope Glass Company in England, which were then shipped to the Rambusch Company in New York. Once there, Rambusch set about the task of creating the map in stained glass. Artists at Rand McNally in Chicago used their 1934 world map to create paper map overlays (known as cartoons) as templates for each panel. Rambusch artists then traced these maps onto 1/4 to 1/2 inch thick glass panels, and then painted them with a colored powdered glass mixture. Each panel was then fired in a kiln to fuse the color to the panel. Different colors required separate firings at temperatures ranging from 1,100 to 1,350 degrees Fahrenheit. To help maintain their exact curve and shape, panels were fired in asbestos cradles. It took eight months to paint and bake all 608 glass panels.
Link (via Proceedings of the Athanasius Kircher Society)