Hooke Invents the Balance Spring Recently, it came to light that polymath Robert Hooke is the true inventor of the balance spring. Initially, Christiaan Huygens had been given credit for this invention because he published a letter in 1675 in the Journal des sçavans that provided details and a diagram of what he stated was his creation, the flat balance spring. Hooke was enraged at this claim. He insisted that he had revealed this very invention to the Royal Society five years earlier and accused Huygens of stealing his idea. Unfortunately, Hooke could not substantiate his claim because his notes of the Royal Society meetings during that period could not be found. Without proof to support his assertions, Huygens was credited for the invention of the balance spring for roughly 300 years. In 2006, Hooke’s notes of the minutes of the Royal Society meetings for the years 1660–1682 were found in a cupboard during a house valuation in Hampshire, England. The entry for 23 June 1670 reads: The curator [Hooke] produced a pocketwatch of a new contrivance devized by himself, which he affirmed should goe as equally as a pendulum, and without stopping, and might be made to goe for 8 days. This proves that Hooke is the true inventor of the balance spring. This invention greatly increased the accuracy of portable timepieces. Image Credits Balance wheel of watch with spiral balance spring. PRIVAT-DESCHANEL et FOCILLON. Uploaded by Jean-Jacques MILAN, Public domain, via Wikimedia Commons Note on pocketwatch by Robert Hooke, 23 June 1670. Taken from the Hooke Folio, draft and copy minutes of Royal Society meetings. MS/847 page 81 ©The Royal Society
