In an old, faded photo from Margaret Nadine Elliott’s 1940 scrapbook, a group of children pose on a sidewalk outside the Hotel Elliott in Astoria. Beneath their feet lie a panel of gridded, smooth glass squares, reflecting light from the afternoon sun.

Today, light still sparkles against the jagged edges of what remains of these glass squares, their fractures giving them an appearance of amethyst or rose quartz. These panels are called vault lights, their name taken from their purpose of allowing natural light into basements extending beneath vaulted sidewalks.

Maritime origins

The vault lights seen in many urban areas are a specific form of innovation that allows daylight to penetrate subsurface areas, which date back to wooden cargo ships in the 17th century. Shipbuilders once set prismatic glass onto the decks of ships, allowing natural light to enter the cargo hull. Daylighting became a widely used alternative to open flame light sources, like candles or kerosene lamps, and was considered an essential feature for ships carrying coal or gunpowder.

The earliest U.S. patent for vault lights on land was created in 1834 by Edward Rockwell, whose vision employed a large glass lens encased within a round iron frame. His lights were installed at a few locations in New York City. Though successful, this glass was vulnerable to damage from frequent foot and wheel traffic. If the glass was scratched, light would no longer penetrate through it effectively. If it was broken, a pedestrian’s foot could fall through the hole it would leave behind.

Inventor and lawyer Thaddeus Hyatt pointed out these flaws in an 1845 patent for improvements on Rockwell’s design.

“I have so constructed my illuminating vault cover, as to admit the light through a considerable number of small glasses, or lenses, which are set into the iron cover, as effectually to defend them from injury by the falling or pressure of weighty bodies upon them,” he wrote.

Hyatt’s improved lights became a hit. The ingenuity of replacing one large lens with smaller, thicker pieces of glass sustained the integrity of the sidewalk’s safety. For building owners, vault lights added to property value and saved them considerable costs for electricity, which was then new and rather expensive. Hyatt became a successful and well-respected man, but his contributions didn’t stop at vault lights.

Rebuilding

The late 19th century was a time when several major cities faced great fires. Hyatt was determined to come up with a solution to fireproof construction. In his experiments, he found that materials like iron and concrete were not effective against fire on their own, but in the form of reinforced concrete, these materials were considered fireproof.

After Hyatt published his work in the late 1870s, reinforced concrete buildings began to pop up all over the country. Astoria had faced its own fire disasters, including the Great Fire of 1922. Prior to the tragic event, Astoria’s infrastructure remained a bit behind the times. The city’s downtown landscape stood atop the tidal flats of the Columbia River. It wasn’t until 1916 that resolve to fill in that area began with the construction of a rocky seawall along the waterfront.

This advancement led to the city raising buildings and streets by 4 feet, allowing for functional basements. But despite these improvements, builders continued to rely heavily on the abundance of timber to construct buildings, sidewalks and streets. This choice accelerated the destruction of new structures.

After the fire, Astoria’s downtown followed a new plan: “From Ashes to Concrete.” For Astoria, a modern city meant building with reinforced concrete. The concept of the seawall was improved upon with the chairwall system, which extended basements to the space beneath the sidewalks.

In 1924, concrete sidewalks were poured by local contractors Solheim & Gustafson. It was at this time that panels of gridded glass, produced by Cress & Co. of Portland, were installed along nearly every block so basements and utility passageways would be illuminated with daylight.

Hues of sunlight

Over time, vault light glass turned purple from years of sunlight exposure, and this solarization seemed to happen everywhere. Even in Astoria, there was enough sun for this transformation to occur.

On an elemental level, glass is made from silicon dioxide, or silica, which is colorless. Impure batches of silica contain iron, imparting a greenish tint to the glass. To resolve this, glass makers used manganese dioxide as a decolorizer, a method that dates back thousands of years.

It was once thought that the decolorizer was scrubbing the color away from the material. In fact, glass books of the 17th century refer to manganese dioxide as “glass maker’s soap.” However, when combined, the manganese chemically reduces while simultaneously acting as an oxidizing agent to the iron, rendering them both colorless.

In turn, when exposed to ultraviolet light for extended periods, the reduced manganese becomes photo-oxidized, or solarized, converting it back to its oxidized form and giving it a recognizable purple color still seen in Astoria’s vault lights.

Vault lights ultimately fell out of fashion around the 1930s when electric lights became more common and more affordable.

For nearly 100 years, pedestrians have been walking across the purple squares, leaving them in various states of decay.

Many Astoria vault light panels continue to line the sidewalks of Commercial and Duane streets, as well as the numbered side streets.

Some remain in great condition, enhanced with lighting from beneath that provides a warm and welcoming glow.

‘Astoria Underfoot’

Early last year, artist Kate Speranza created “Astoria Underfoot,” a project made from the glass she acquired from a discarded panel. The collection includes 100 brooches that represent a grid of 100 squares of Astoria’s historic sidewalk vault lights.

“I am fascinated with the history that is imbued within architectural structures and surfaces, and I find inspiration in the inevitable patina that develops through human interaction, age, and the elements,” Speranza said. “Ultimately, I wanted to honor the history of this glass that has been tread upon for 100 years. The state of the sidewalk grids as they are today are evident of that history and so capturing the overall look of the squares that have been fractured, replaced or filled in with other materials, the accumulated debris, and plant life (moss) were all elements I wanted to include in the gridded installation.” Speranza’s work can be found at RiverSea Gallery in Astoria.

Additional projects to help preserve the history of the lights have been facilitated by local nonprofits, including outreach and restoration grant opportunities.

Astoria is a place to experience history hands-on, where you can drink a beer in a century-old auto showroom or shop for toys in a building from 1916, or take a walk downtown to see the vault lights. There are a few places that especially highlight the history of the panels.

The sidewalk at 11th and Commercial streets shows the lights in their best condition, while a replacement panel can be found by the Hobson Building. Everywhere one looks, there is a story to be told.