" At The beginning, these wristwatches were 1-off or personalized creations that often looked lots much like the pocket watches from which they progressed. But before long, wristwatches took by themselves aesthetic, with their very own complex improvements to solve new problems presented by wrist-borne timekeepers. Exclusions may perhaps use. https://www.watchesworld.com/a-history-of-watch-reference-numbers/