exceptionally rare and highly sought after all original 19th century antique american exterior city of chicago sidewalk vault light panel fragment designed and fabricated by the richards and kelly mfg. co., chicago, il. interlocking vault light panels date back to the mid-9th century and were designed to be set into sidewalks to provide natural lighting for vaulted rooms or cellars found in the basements of 19th century city commercial buildings. the fragment is comprised of thick cast iron that has been brushed and lightly polished. the majority of the sun-purple circular-shaped glass insets are mounted tightly within the closely spaced openings. slightly raised "nubs" configured in sets of five surrounding the glass insets provides traction and minimized wear and/or damage to glass insets. several sections, along with fragments of various sizes and shapes were recently acquired from chicago sidewalks undergoing extensive rebuilding. richard and kelly manufactured several cast iron elements that combined the use of glass lenses or insets for use with natural light. their circular-shaped cast iron coal chute covers gained widespread popularity during the 19th century when coal was used as the primary source of for heating commercial and residential structures alike. each fragment offered for sale has been sealed with a clear coat finish. the vault light sections are especially visually appealing when illuminated from behind. very limited number of sections available for sale. priced individually. measures 19 1/2 x 10 inches.