Gas lighting was used for public lighting and interior lighting in both residences and businesses. (The photo at left was taken specifically to document the 15 gaslight fixtures installed by Bertrams Gas Co.) The gas used was not the natural gas that powers our furnaces and ranges today, but coal gas which was accidentally discovered in the 1840's as a by-product of tar production.

Detroit had its main gasworks (coal gasification plant) on the riverfront just west of Belle Isle. After gas was extracted from the coal, it was stored, then delivered to users through a network of pipes laid under city streets.

The primary drawback to gas lighting was the danger of fire, particularly indoors. Leaking or partially closed light fixtures could fill a room or building with an explosive volume of gas, resulting in a deadly blast that often led to fire. The Great San Fancisco Earthquake of 1906 is also known as The Great Fire because the greater part of its destruction was the result of fire caused by the quake-shattered gas lighting network. Detroit newspapers of the gaslight era are filled with tragic reports of whole families and blocks of homes being lost in gas explosions or fires. Apparently, turn-of-the-century Detroiters resignedly accepted these in the same way they would later accept motor vehicle accidents, as part of the cost of Progress.

Further, gas light, known for its soft glow, was not the total lighting source we have come to expect from electric lighting. Indoors, it was barely adequate, but outdoors, the dim glow scarcely carried from the lamppost, creating a shadowland on the street below.

Arc lighting, which gives a bright light similar to a modern mercury vapor lamp, offered a solution to this problem. In the type of arc lighting used here on Campus Martius, an electric current is passed between two carbon electrodes, creating an arc (sort of a spark of continuous duration). Light results from both the arc and the incandescence of the carbon electrodes as they burn in the open air.

In the 1880's, the City of Detroit contracted for six arc lighting towers in downtown around Campus Martius. Direct current electricity to the towers was supplied by a coal-burning generator located nearby. Contemporary accounts report that the light was abundant if perhaps surreal in cast. (Arc light, like its modern cousin, the flourescent light, contains a narrower spectrum of light than gas or incandescent.)

Though the arc lighting towers continue to appear in downtown photographs up to the late 1910's, it is unclear when they fell into disuse. Requiring frequent replacement of the carbon electrodes, they presented a maintenance headache. Further, they were unable to be integrated into the expanding alternating current power grid being developed for incandescent lighting. At some point, the city installed incandescent fixtures on ordinary streetpoles and abandonned the tower-mounted arc lights.

Left, Campus Martius ca. 1920 is seen at night lit by incandescent lighting from both public lightpoles and commercial signs.

Today, mercury vapor lamps, descendants of arc lights, sit atop downtown skyscrapers casting a shopping-mall-parking-lot glow on the usually abandonned public square below.