The earliest patent of deck lights, which predate vault lights or sidewalk prisms, is from 1684. This site includes some images and patents https://glassian.or

The earliest patent of deck lights, which predate vault lights or sidewalk prisms, is from 1684. This site includes some images and patents https://glassian.org/Prism/index.html https://glassian.org/Prism/index.html There's a patent for sidewalk prisms from 1834. As other people have said, the glass broke. > In 1834, Edward Rockwell patented a round iron plate with a single large lens, but Hyatt later complained in his own patent application, "These glasses are extremely liable to fracture, and when broken leave large and dangerous openings within their rims...". Rockwell's plates are rare today; I know of only three examples of the iron covers and none of the lenses