人行道上那些漂亮的玻璃棱镜是做什么用的

人行道上那些漂亮的玻璃棱镜是做什么用的

Have you ever walked along a city street and noticed grids of colored glass on the sidewalk? Though the patterns are lovely and may seem decorative, they actually served a purpose — or at least they did at one time. 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.

你是否曾经走过城市的街道，注意到人行道上五颜六色的玻璃网格?尽管这些图案很可爱，看起来像是装饰性的，但它们实际上是有目的的——或者至少曾经是。这些玻璃碎片是拱顶灯，在英国有时被称为路面灯。

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

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.

据Glassian网站报道，1834年，爱德华·洛克威尔为第一盏拱顶灯申请了专利。该网站致力于研究玻璃收藏和玻璃历史。它是一个大玻璃镜片周围的圆形铁板。

A pavement light outside Burlington House in London. (Photo: Etan J. Tal [CC BY-SA 3.0]/Wikipedia)

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.

1845年，撒迪厄斯·凯悦提交了自己的专利申请，抱怨罗克韦尔的电灯容易损坏。相反，他提出了一个铁板包含小玻璃碎片，由突出的铁旋钮保护。这些是你今天最有可能看到的光。

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.

拱顶灯的顶部与人行道是平的，这样人们可以直接从上面走过，但底部通常有不同的形状。

Some of them have a prism design so the bottom can spread as much light as possible through a broad area, explains GBA Architectural Products. "In some cases, multiple prisms set at different angles would be incorporated to spread the light evenly throughout an even larger room."

GBA建筑产品解释说，其中一些有棱镜设计，所以底部可以通过一个广阔的区域传播尽可能多的光。“在某些情况下，设置在不同角度的多个棱镜会被合并在一起，使光线均匀地散布在更大的房间里。”

Sidewalk prisms at Elizabeth Street in Sydney. (Photo: Mike [CC BY-SA 2.0]/Flickr)

These sidewalk prisms were first used on the decks of ships.

这些人行道上的棱镜最初是用在甲板上的。

"It's long been the traditional way of lighting the interior of ships," Diane Cooper, a museum technician at the San Francisco Maritime National Historic Park, told KQED News. "While kerosene lamps were sometimes used, the smoke could make interior spaces uncomfortable. And candles could become a fire hazard on wooden ships."

旧金山海事国家历史公园的博物馆技术人员黛安·库珀告诉KQED新闻记者:“长久以来，这一直是照亮船只内部的传统方式。”“虽然有时使用煤油灯，但烟雾会让室内空间不舒服。蜡烛可能成为木船的火灾隐患。”

Bunn Building vault lights in Waycross, Georgia. (Photo: Michael Rivera [CC BY-SA 3.0]/Wikimedia Commons)

The lights became popular in U.S. cities like New York, San Francisco, Chicago, Philadelphia and Seattle. Internationally, the lights came to be found everywhere from London to Dublin, Amsterdam to Toronto. The idea eventually spread to even smaller cities.

这种灯在纽约、旧金山、芝加哥、费城和西雅图等美国城市流行起来。在国际上，从伦敦到都柏林，从阿姆斯特丹到多伦多，到处都可以看到灯光。这个想法最终传播到了更小的城市。

They were a way to illuminate spaces where natural light wasn't available and a way to avoid using gas, oil and candles.

它们是一种照亮没有自然光的空间的方式，也是一种避免使用天然气、石油和蜡烛的方式。

Vault light in front of 239 Chestnut in Philadelphia. (Photo: Susan Babbitt [CC BY 2.0]/Flickr)

Vault lights can be various colors, but they are often found in shades of purple.

拱顶灯可以是各种各样的颜色，但它们通常是紫色的阴影。

When the lights were originally put in place, many of the glass pieces were clear. But during older glass manufacturing, chemists would mix in manganese dioxide during the process. That would stabilize the glass and take away the greenish tint it got from other elements.

当灯光最初安装到位时，许多玻璃碎片是透明的。但是在旧的玻璃制造过程中，化学家会在这个过程中加入二氧化锰。这样可以稳定玻璃，去掉玻璃从其他元素中得到的绿色。

Over the years, as manganese is exposed to ultraviolet rays, it turns purple or even pinkish, KQED reports. The colored glass today is either very old or has been dyed to look like old glass.

多年来，锰暴露在紫外线下，会变成紫色甚至略带粉红色，KQED报道。今天的彩色玻璃不是很旧就是被染成旧玻璃的样子。

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

The use of vault lights declined by the 1930s when electricity became more common and inexpensive. As the glass pieces cracked in places, they became hazards to pedestrians as well as the subterranean spaces down below as they let in moisture. Cities began to cover or remove them.

20世纪30年代，随着电力变得更加普遍和便宜，保险库照明的使用开始减少。随着玻璃碎片在一些地方裂开，它们对行人和下面的地下空间造成了危害，因为它们让湿气进入地下。城市开始覆盖或移走它们。

Old sidewalk prisms in an underground alleyway in Seattle. (Photo: Britta Gustafson [CC BY-SA 2.0]/Flickr)

However, some preservation groups are working to restore the lights for their historic and aesthetic value. Some cities, like Seattle, offer tours that show where the vault lights are located and have done studies on their history and value.

然而，一些保护组织正在努力恢复这些灯的历史和美学价值。有些城市，比如西雅图，会提供参观服务，告诉游客拱顶灯的位置，并对它们的历史和价值进行研究。

Says GBA, "Since many vault lights panels have lasted for more than a century, these cityscape artifacts have become prized historical treasures."

GBA说，“由于许多拱顶灯面板已经持续了一个多世纪，这些城市景观文物已经成为珍贵的历史宝藏。”

Pavement lights in Portugal. (Photo: Daderot [public domain]/Wikipedia)

Vault light in front of a house at 1006 Clinton, Philadelphia. (Photo: Susan Babbitt [CC BY 2.0]/Flickr)