At a time when electricity itself had not yet been invented, much less luminescent hands, it was convenient to be able to listen to the time instead of searching for it in the dark. The minute repeater is an entirely mechanical and complex system which chimes the time by request only, striking the hours, quarter-hours and minutes shown by the hands. A repeater mechanism is clearly audible and features a low tone for the hours, a double high-low tone for quarters and a high tone for minutes.