Robert Hooke Invented the Straight Spring

Sir Robert Hooke

If we could have a subtitle for this story, it would be “when a lousy personality becomes your biggest liability.” But I’m getting ahead of myself. Let’s start with this: what is a hairspring (a.k.a., balance spring) and why was its invention by Robert Hooke one of the most important innovations in all of horology?

The balance spring is a fine spiral or helical torsion spring used in mechanical watchesalarm clocks, kitchen timersmarine chronometers, and other timekeeping mechanisms to control the rate of oscillation of the balance wheel.

The balance spring is an essential adjunct to the balance wheel, causing it to oscillate back and forth. The balance spring and balance wheel together form a harmonic oscillator, which oscillates with a precise period or “beat” resisting external disturbances, and is responsible for timekeeping accuracy.

The addition of the balance spring to the balance wheel around 1657 by Robert Hooke and Christiaan Huygens greatly increased the accuracy of portable timepieces, transforming early pocket watches from expensive novelties to useful timekeepers. 

Robert Hooke Gregorian telescope

wikipedia’s editors give Mr. Hooke and Mr. Huygens equal credit for inventing the hairspring (initially a straight design, evolving into a spiral). Wrong answer. That argument’s been settled, as you will see. It’s what you don’t read at Mr. Hooke’s bio page that makes all the difference.

The first man to visualize a microorganism, build the earliest Gregorian telescope (above), infer a wave theory of light, argue that geology elevated fossils to the surface and more was no charmer. In fact, Sir Robert Hook’s horological legacy was ruined by the simple fact that the Brit was a royal pain-in-the-ass.

You might even say he was an arrogant prick. Hooke called Thomas Tompion – the father of British clockmaking – a “clownish churlish dog” and a “slug.” As Tompion was Hooke’s business partner, it’s easy to understand why Hooke was not overly loved by his peers.

Sir Robert Hooke again

Chronicles from the era describe Hooke as irascible, grating and extremely jealous of his discoveries. He was prone to accusing other scientists of “stealing” his scientific insights without giving him due credit.

Robert Hooke’s character would prove his downfall; he was literally robbed of recognition for the creation of the hairspring. That honor went to the aforementioned Christiaan Huygens . . .

Christiaan Huygens

The Dutch mathematician, physicist, astronomer and inventor was just as intellectually gifted as Robert Hooke. But Huygens had a far more affable personality.

An extremely low bar to be sure, but the Dutchman was friends with everyone – especially Royal Society President Sir Isaac Newton. Hooke’s sworn enemy, thanks to a dispute over which of the two first postulated “that gravity heeds an inverse square law, and first hypothesised such a relation in planetary motion.”

Huygens treatise

In 1673, Huygens published his catchily-titled treatise Horologium Oscillatorium: Sive de Motu Pendulorum ad Horologia Aptato Demonstrationes Geometricae (The Pendulum Clock: or Geometrical Demonstrations Concerning the Motion of Pendula as Applied to Clocks). It outlined Huygens design for a hairspring-based regulator.

In 1675, Huygens sent a letter to the Journal des sçavansEurope’s earliest academic journaldescribing and illustrating a regulator formed with a concentric spring, now known as a hairspring.

Robert Hooke went ballistic (a term yet to be invented). It was his idea! Hooke loudly, constantly and publicly accused Huygens of stealing his invention. He insisted he’d presented the same device to the Royal Society in 1670, five years before Huygens debuted his regulator.

Henry Oldenburg

To establish primacy, Hooke asked for the acts of The Royal Society containing a registration of his presentation. The secretary couldn’t find the relevant document. The record had vanished, leaving Hooke without any demonstrable evidence of his claim.

The case rampaged through the scientific community. Where were the missing documents? Who could have removed them? Had Hooke’s arch enemy Isaac Newton used his position in the Society to disappear the record of Hooke’s invention?

Suspicion fell on Henry Oldenburg (above), German theologian, inventor of scientific peer-review and the Royal Society’s first secretary. Responsible for the official minutes, Oldenburg was also the Society’s liaison with foreign members. Newton was his boss and friend, Huygens was one of his most prominent correspondents.

Eventually Robert Hooke’s protests were labelled lies, attributed to his character (i.e., the lack thereof). His claim to have invented the hairspring was quietly forgotten. That was that: Huygens 1, Hooke 0. Until 2006 . . .

Royal Society's notes

That year a large collection of Robert Hooke’s notes was discovered in a cupboard in a house in Hampshire, in the south of England. Along with these documents, treasure hunters found the missing Royal Society minutes re: Hooke’s hairspring.

Not the official minutes. Royal Society Secretary Oldenburg’s drafts of the minutes. That Robert Hooke had stolen from Oldenburg. Notes that Hooke couldn’t reveal in his lifetime lest he face public scandal and ejection from The Royal Society.

Hooke had hoisted himself by his own petard. Thanks to the inventor’s perfidy and paranoia, Oldenburg couldn’t register Hooke’s hairspring invention.

Rolex hairspring

Quite apart from Robert Hooke’s [now verified] claim to have invented the straight spring, horology experts consider Hooke’s proposed regulator system clunky and difficult to produce. In contrast, Huygens’ solution was elegant and simple, leading to the first working prototype. In short, Hooke invented it, Huygens perfected it.

After 350 years, the strange case of the hairspring’s invention has finally been settled in favor of the hateful, haughty, thieving Robert Hooke – both the villain and the victim in this ironic twist of horological history.


  1. And know you know… the rest of the story! I love history filled with relatable characters and not lionized Mary Sue’s.
    “The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” — George Bernard Shaw

    • The technical term hairspring in relation to Hooke’s invention is incorrect, he invented a straight spring to the balance. A hairspring is in the form of a spiral and is something totally different.

      • Text amended as follows: “wikipedia’s editors give Mr. Hooke and Mr. Huygens equal credit for inventing the hairspring (initially a straight design, evolving into a spiral).”

        Is that correct?

  2. Thank you, another interesting article on your website. I’m interested in watches but find only a very few web sites on this topic worth reading, such as yours.

    • Indeed, I am thinking about writing a play out of this. There is a lot of potential for a comedy of misunderstandings

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