Street light

A street light, light pole, lamppost, street lamp, light standard, or lamp standard is a raised source of light on the edge of a road or path. When urban electric power distribution became ubiquitous in developed countries in the 20th century, lights for urban streets followed, or sometimes led. Many lamps have light-sensitive photocells that activate automatically when light is or is not needed: dusk, dawn, or the onset of dark weather. This function in older lighting systems could have been performed with the aid of a solar dial. Many street light systems are being connected underground instead of wiring from one utility post to another.

The use of street lighting was first recorded in the city of Antioch from the 4th century. Later it was recorded in the Arab Empire from the 9th–10th centuries, especially in Cordova. In the Middle Ages, so-called "link boys" escorted people from one place to another through the murky winding streets of medieval towns.

Before incandescent lamps, candle lighting was employed in cities. The earliest lamps required that a lamplighter tour the town at dusk, lighting each of the lamps. According to some sources, illumination was ordered in London in 1417 by Sir Henry Barton, Mayor of London though there is no firm evidence of this.

In 1524, Paris house owners were required to have lanterns with candles lit in front of their houses at night, but the law was often ignored. Following the invention of lanterns with glass windows, which greatly improved the quantity of light, in 1594 the police of Paris took charge of installing lanterns in each city neighborhood. Still, in 1662, it was a common practice for travelers to hire a lantern-bearer if they had to move at night through the dark, winding streets. Lantern bearers were still common in Paris until 1789. In 1667, under King Louis XIV, the royal government began installing lanterns on all the streets. There were three thousand in place by 1669, and twice as many by 1729. Lanterns with glass windows were suspended from a cord over the middle of the street at a height of twenty feet and were placed twenty yards apart. A much-improved oil lantern, called a réverbère, was introduced between 1745 and 1749. These lamps were attached to the top of lampposts; by 1817, there were 4694 lamps on the Paris streets. During the French Revolution (1789–1799), the revolutionaries found that the lampposts were a convenient place to hang aristocrats and other opponents.

The first widespread system of street lighting used piped coal gas as fuel. Stephen Hales was the first person who procured a flammable fluid from the actual distillation of coal in 1726 and John Clayton, in 1735, called gas the "spirit" of coal and discovered its flammability by accident.

William Murdoch (sometimes spelled "Murdock") was the first to use this gas for the practical application of lighting. In the early 1790s, while overseeing the use of his company's steam engines in tin mining in Cornwall, Murdoch began experimenting with various types of gas, finally settling on coal-gas as the most effective. He first lit his own house in Redruth, Cornwall in 1792. In 1798, he used gas to light the main building of the Soho Foundry and in 1802 lit the outside in a public display of gas lighting, the lights astonishing the local population.

This page was last edited on 16 June 2018, at 01:51 (UTC).
Reference: https://en.wikipedia.org/wiki/Street_lamp under CC BY-SA license.

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