"An Educational guideline around the heritage of British watchmaking. Horology supporters of all degrees are sure to locate price here." The 3rd massive move happened in the early 1900’s. The shape from the timekeeping apparatus transformed in favor of your wristwatch. The 1st chronometer wristwatch motion came in about 1910, https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/