The Arco Lamp Is a Street Light That Moved Indoors

In 1962 Flos put a floor lamp into production that you cannot lift alone. Its base is a block of white Carrara marble with a hole cut through it, and the hole is there so that two people can slide a broomstick through and carry the thing between them. Above the marble a stainless steel arc climbs to about 2.5 meters and swings out about 2 meters, so the polished aluminum shade hangs over the middle of a room with nothing beneath it.

The designers were Achille and Pier Giacomo Castiglioni, two architect brothers from Milan. Sixty-four years later the Arco is still in the Flos catalog, still looks like nothing else in a living room, and still needs two people and a broom handle to move.

Two brothers in Milan

Achille Castiglioni was born in Milan on February 16, 1918, and died there on December 2, 2002. He trained as an architect, as did his brothers Livio and Pier Giacomo. Achille and Pier Giacomo worked side by side on many projects until Pier Giacomo's death in 1968, and the Arco carries both names.

Their method was to start from something that already existed and ask what it was really for. Wikipedia describes the brothers working with Marcel Duchamp's idea of the ready-made, taking existing objects and putting them to new use. The Mezzadro stool of 1957, made by Zanotta, is built around a stamped metal tractor seat. The Sella stool from the same year uses a bicycle saddle. In 1962, the year of the Arco, Flos also launched their Toio floor lamp, which uses a surplus transformer and an automobile headlamp. Borrowing from the street and the farm runs through all of it, and it is why Castiglioni objects still look clever rather than dated.

The Arco belongs to the same family of engineering-first lights as the Anglepoise, even though one came from Milan and the other from an English engineer's workshop. Both begin with a mechanical problem, and both are solved by balance and geometry rather than ornament.

The problem of the light in the middle of the room

The Arco answers a simple question. How do you put light over the center of a room, or over a dining table, without drilling into the ceiling? A street lamp does it outdoors with a post set in the ground and an arm that reaches out over the road. Retailer and design-history accounts, including Design Index and the American dealer hive, agree that the Castiglionis took the street lamp as their model.

Moving that idea indoors created two problems. The first is reach. Design Index describes the arc as three sliding stainless steel sections with a U-shaped profile, which lets you set the reflector at three different heights. Fully extended, the shade sits about 2 meters from the base.

The second problem is that an arm that long wants to tip the whole lamp over. The answer is mass, placed as low as possible. According to hive, the brothers first considered concrete and then switched to marble, which gave the same weight in a smaller volume, with a better finish and at a lower cost. The corners of the block are bevelled and rounded. Hive says that is functional too, since a sharp-edged stone block at shin height is a hazard.

How heavy is it, exactly

Here the sources wobble a little. Design Index puts the marble base at about 65 kilograms. Hive lists the complete lamp at 141.3 pounds, about 64 kilograms, for the original incandescent version. Either way, it is heavier than many of the people who own one, and the broomstick hole is not a joke.

Most of that weight sits in the stone. The arc and the shade are light, which is the whole point. A heavy base and a light arm is the same principle that keeps a crane upright, applied to a reading light.

The Arco by the numbers

The figures below come from Design Index, hive and Wikipedia. Where they differ, both are shown.

Sixty-four years in one catalog

The Arco has stayed remarkably constant. Design Index notes that over its production life the only change was an update to the electrical system to meet current standards. The later step was light source. Hive reports that Flos launched an Arco LED for the lamp's 50th birthday, which was also the company's own 50th, and the LED version keeps the same height, reach and shade.

That continuity matters to buyers. A vintage Arco and a new one are close to the same object, which is unusual for a design this old. Compare it with the Eames Lounge Chair, whose materials and makers shifted over the decades, or with the Panton Chair, which went through five materials. The Arco simply kept being made.

It also became one of the most copied lamps in the world. Arched floor lamps with a heavy base and a dome shade are sold at every price, and almost all of them owe the idea to this one. The tell is usually the base. A real Arco stands on a single block of marble with rounded corners and a hole through it.

The Castiglioni legacy

Wikipedia credits Achille Castiglioni with eight Compasso d'Oro awards, Italy's leading design prize, plus a career award. Some retailers, including hive, say nine, so the count depends on how you treat that last one. The Museum of Modern Art in New York gave him a retrospective in 1997, curated by Paola Antonelli, and holds his work in its collection.

His studio in Milan is now a museum run by the Fondazione Achille Castiglioni. According to Wikipedia, its archive holds records of 191 architectural projects, 484 installation projects and 290 industrial design projects. If you are in town for Milan Design Week, check the foundation's site for visiting arrangements and closures before you go.

The Castiglionis' wit also explains a later Milanese generation. The Memphis group broke the rules loudly in the 1980s. The Castiglionis broke them quietly two decades earlier, with a tractor seat, a bicycle saddle, a car headlamp and a street lamp. For more lighting and furniture history, see our pieces on Isamu Noguchi's Akari lamps, the industrial design hub and the full Design section.

Living with one

An Arco wants space. With a reach of about 2 meters it is built to cross a room, and Design Index suggests the classic placement, with the base tucked into a corner and the shade hanging over a dining table. It works over a sofa too, as long as nobody needs to walk between the base and the light.

If you are buying vintage, check the marble for chips at the corners, look for the hole through the block, and make sure the arc sections still slide and lock. Then find a friend and a broom handle. That part of the design has not changed since 1962.