Aluminum: Common Metal, Uncommon Past

Lockheed lounge by Marc Newson

Lockheed lounge by Marc Newson

Paul Héroult

Hall's French counterpart, Paul Louis-Toussaint Héroult, was born on 10 April 1863 in the small Normandy town of Thury-Harcourt. Indeed, the two were a study in contrasts. Whereas Hall was the child of learned, college-educated parents, Héroult's father ran a tannery and had at one time been a laborer at a Deville-process aluminum plant; whereas Hall was known as a quiet, obedient, studious child, Héroult was sent to a series of boarding schools, possibly in part to tame his rebelliousness. He read Deville's famous book about aluminum while at Sainte-Barbe Academy in Gentilly (near Paris) and became obsessed with the subject.

In 1882 Héroult entered the École des Mines in Paris. But there he apparently neglected his other studies while chasing his aluminum dreams, for he was failing his courses and was asked to leave after only a few months. (Héroult himself later claimed he was ejected because he threw a wet sponge that hit the dean.) So while Hall was continuing his studies with Professor Jewett, Héroult found himself in the army until his honorable discharge in 1884.

Héroult's father died suddenly in 1885, leaving the 22-year-old Paul in possession of the family tannery, including its steam engine. Paul seized the opportunity to continue his experiments with aluminum and persuaded some friends from the École des Mines to join him. But first he convinced his mother to give him 50,000 francs for a 400-amp, 30-volt dynamo—no small amount at a time when a kilogram of meat was 2 francs and red wine half a franc per liter. Like Hall, he ultimately decided on molten cryolite as a solvent and made his first extraction on an unrecorded date. But two dates are certain: Héroult preceded Hall in filing his patent on 23 April 1886 in France and on 22 May 1886 in the United States.

Sharing an Achievement

Fortunately the two innovators were ultimately able to come to an amicable understanding; Héroult held the earlier patent, but since Hall had demonstrated his process in February of 1886 in Oberlin, Hall's work took precedence. Today their invention is known as the Hall-Héroult process, and they were friendly enough for Héroult to deliver a warm speech about Hall's contributions at the ceremony in which the latter received his Perkin Medal in 1911.

In the end it was Charles Hall's entrepreneurial spirit, coupled with persistence and some lucky breaks, that made him the big winner in the aluminum game. His first, unsuccessful attempts to commercialize his process included a stint at the Lockport, New York, plant of the Cowles Electric Smelting and Aluminum Company that would later lead to a contentious patent dispute. Eventually Hall found a backer in Captain Alfred Epher Hunt (of no relation to contemporaneous Bethlehem Steel Corporation founder Alfred Hunt), who with coinvestors provided $20,000 to build a pilot plant in Pittsburgh. That partnership would lead to the formation of the Pittsburgh Reduction Company, which in 1907 became the Aluminum Company of America, and under its current name of Alcoa is the world's largest producer of aluminum.

Héroult's life after the discovery continued to contrast with Hall's. While Hall dedicated himself single-mindedly to the aluminum industry, Héroult took a greater interest in aluminum alloys and eventually moved on to other industries. Unlike Hall, who remained single and childless until his death, Héroult married twice and fathered five children. While Hall's main pleasures outside the lab were reading, playing the piano, his family, and Oberlin college, Héroult enjoyed overseeing grand engineering tasks. Hall's further patents were firmly in the field of aluminum production, but Héroult developed several non-aluminum inventions, such as a helicopter prototype and the "hydroslip, a sort of boat on runners, lifted by four propulsive vanes," designed with American inventor Cooper Hewitt. Today he is perhaps most famous for inventing the electric arc furnace, still in use for steel recycling. Hall died of leukemia in Florida; Héroult died of typhoid fever and cirrhosis shortly after moving to a 100-foot yacht in the Mediterranean. And just as they shared a birth year and discovery year, they were joined together in year of their death—1914. Héroult lived only eight days longer than Hall.