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The apex of the Washington Monument

Shortly after aluminum was first discovered in the early 19th century it was counted among the most precious metals on Earth owing how difficult it was to obtain the pure metal. At $1,200 per kilogram, it was worth more by weight than gold or platinum.

By 1884 the price had fallen a little, but it was still valuable enough that the US government commissioned a pyramid of the metal to use as the apex of the US Washington Monument. At 100 ounces it was the largest single piece of aluminum ever cast at that time. Before engineers affixed it to the top of the new tower in an elaborate ceremony, the pyramid spent two days in the window of Tiffany’s in New York City, gawked at by passers-by.

Later in the 1880s, however, researchers found a new method to extract aluminum from common bauxite. The price plummeted to $0.60 per kilogram by the early 1900s. Scientists now know that aluminum is the most abundant metal on Earth.

Although the element’s discoverer Humphry Davy originally named it “aluminum”, a name which follows the -um pattern established by similar elements (platinum, molybdenum, etc), the metal is known as aluminium in most places outside of the United States. This is due to an anonymous contributor to the British journal Quarterly Review in 1813 who felt “aluminum” was not sufficiently ostentatious, and insisted with inexplicable success that chemists insert the superfluous vowel.

When the Wright brothers needed a lightweight engine for their heavier-than-air flying machines, they used aluminum, but painted it black to throw their competitors off the scent. Still, aluminum proved too malleable to be a common aircraft building material until 1901, when German scientist Alfred Wilm accidentally discovered that an aluminum alloy with about 4% copper, heated to high temperatures and then left to slowly cool, was considerably stronger than aluminum alone, or any alloy cooled with the rapid “quench hardening” used for other metals. This slow-cooled alloy is an integral part of airplanes and architecture even today.

Although it is not the best conductor of electricity, aluminum is used almost exclusively in main overhead power lines due to its light weight. If a better conductor such as copper were used, many more poles and pylons would be necessary to keep the lines aloft.