Vault Lights

One wouldn’t think that such an ordinary every day thing such as a vault lights would be so intriguing, especially as they are essentially just windows in the ground. But these foot worn, unnoticed paving stones could in fact be windows into our past and may shed light on more than just the floor below.

Lets start with the Wiki Quote:

Pavement lights (UK), vault lights (US), floor lights, or sidewalk prisms are flat-topped walk-on skylights, usually set into pavement (sidewalks) or floors to let sunlight into the space below. They often use anidolic lighting prisms to throw the light sideways under the building. They were developed in the 19th century, but declined in popularity with the advent of cheap electric lighting. Older cities and smaller centers around the world have or have had pavement lights. Most such lights are approximately a century old, although lights are being installed in some new construction.

Wiki Picture

The first vault light was patented in 1834 by Edward Rockwell, reports Glassian, a site devoted to glass collections and glass history. It was a round iron plate surrounding a large glass lens.

In 1845, Thaddeus Hyatt proffered his own patent application complaining that Rockwell’s lights were easy to fracture. He instead proposed an iron plate containing small glass pieces, protected by protruding iron knobs. Those are the lights you’re most likely to still see today.

Source “What Those Beautiful Glass Prisms in the Sidewalk Are Really For

So what do we know about vault or paving lights?

We know cities such as New York, San Francisco, Chicago, Philadelphia, Seattle, London, Dublin, Amsterdam, Toronto have such installations. But how many other places still have these?

Paving lanterns would mean a road and pavement could be laid over the mud (see MFT), and light could still be provided to the submerged floor below.

You can find these by simply looking down.

Sidewalk glass prisms in San Francisco. (Photo: Mike [CC BY-SA 2.0]/Flickr)

“The glass pieces are vault lights, sometimes called pavement lights in the U.K. They were inserted into the sidewalk to allow light into the basement areas below ground.”

A pavement light outside Burlington House in London. (Photo: Etan J. Tal [CC BY-SA 3.0]/Wikipedia)
Sidewalk glass prisms around Melbourne’s Collins Street. (Photo: Mike [CC BY-SA 2.0]/Flickr)

The top of the vault lights are flat with the sidewalk so that people can walk right over them, but the bottom often has a different shape.

Sidewalk prisms at Elizabeth Street in Sydney. (Photo: Mike [CC BY-SA 2.0]/Flickr)
Bunn Building vault lights in Waycross, Georgia. (Photo: Michael Rivera [CC BY-SA 3.0]/Wikimedia Commons)
Vault light in front of 239 Chestnut in Philadelphia. (Photo: Susan Babbitt [CC BY 2.0]/Flickr)

Over the years, as the manganese is exposed to ultraviolet rays, it turns purple or even pinkish, KQED reports. This can be a good indication of the age of the installation, although replacement glass can sometimes be dyed to give it the aged look.

Vault lights as seen from below in Seattle. (Photo: Britta Gustafson [CC BY-SA 2.0]/Flickr)

As electricity was re-introduced during the 1930’s, many vault lights were covered over and removed. The original design allowed for the individual glass refactors to be replaced.

Old sidewalk prisms in an underground alleyway in Seattle. (Photo: Britta Gustafson [CC BY-SA 2.0]/Flickr)
Pavement lights in Portugal. (Photo: Daderot [public domain]/Wikipedia)

The TB Community MFT Challenge

We will keep diving deeper in to this subject, but there are only so many places we can visit.

So, we need your help to collect evidence on mudfloods. If you find anything in your local area that you would like included in a future post we would love it if you could send your photos to:

What evidence have you found in your local area that can prove the MFT?

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