In many ship photographs taken between about 1916 and 1940, there are what appear to be large clocks on the front and rear superstructures or masts. These are actually devices to tell the other ships in the formation at what range that ship is firing at. Together with “Declination Marks” on the sides of turrets; these mechanisms allowed the other ships in the formation, whose view of the target may be obscured by fog, gun smoke or funnel smoke, to have their guns at the proper elevation and bearing when their view becomes unobstructed. This greatly reduced the time needed before they were ready to fire