" To Start with, these wristwatches have been one-off or custom creations that often looked a lot just like the pocket watches from which they progressed. But before long, wristwatches took on their own aesthetic, with their unique technical improvements to solve new issues introduced by wrist-borne timekeepers. Up-and-coming Danish https://www.watchesworld.com/a-history-of-watch-reference-numbers/