Manipulate the massive second hand and cooperate While using the 9 o'clock dial to accurately depend the seconds Perhaps most vital with respect to horological history writ big was the debut in the “Omega” caliber in 1894, a 19-ligne, crown-set motion whose interchangeable parts had been meant for uncomplicated assistance. https://www.watchesworld.com/a-history-of-watch-reference-numbers/