A repeater is a complication in a mechanical watch that chimes the time on demand by activating a pusher or a slide-piece. Different types of repeaters allow the time to be heard to varying degrees of precision, from simple quarter hour repeaters which strike one tone for the number of hours and subsequent tones for each quarter hour, to minute repeaters which strike the time down to the exact minute using a variety of different tones for hours, quarter hours and minutes.
These types of watches have a long heritage in the area of striking watches and are considered one of the most sophisticated and difficult complications to achieve. Originating before the widespread use of electricity, they allowed time to be determined in the dark (and were also used by visually impaired). Now days we can flick on a light to check the watch dial, or it aluminates for us, but the appeal and technical skill required to accomplish a repeater timepiece still fascinates and challenges us.
Ennobling refers to the manual art of enhancing a movement via certain highly skilled techniques as:
A crown (also called a stem or a pin) is the button on the outside of the watch case that is used to set the time and date.
In a mechanical watch, the crown also winds the mainspring. In this case it is also called a winding stem. A screwed-in crown (or screwed-down crown) is used to make a watch more water-resistant. The crown actually screws into the case thereby increasing the water-tightness of the overall watch.