The difference between these two movements is the way in which the watch is wound. Manual-winding watches must be wound every day by hand using the crown, whereas self-winding watches are wound by an internal rotor which responds to wrist movements.
2, What is the precision tolerances of mechanical watches?
The accuracy of the watch depends on the movement and individual habits of the wearer. The majority of mechanical watches (excluding certified chronometers) have average precision tolerances of between -10/+30 seconds per day. the mechanical movement's average precision must be between -4/+6 seconds per day.
3,What is the precision tolerances of quartz watches?
The precision tolerance of quartz watches is around -0.5 to +0.7 seconds per day (excluding certified quartz chronometers). Exposure to significant variations in temperature can have a slight effect on quartz movements.
4, How much is the power reserve of our self-winding mechanical watches and how do they work?
The power reserve of a self-winding watch depends firstly on the type of movement. When fully wound, the movements of our watches have a power reserve of between 36 and 80 hours. The power reserve also depends on the wearer's individual habits and activity. As an indication, 10 to 12 hours' wear should be sufficient to generate a power reserve of 20 hours or more, which ensures that the watch will continue to run throughout the night.
5, Why some of our watches use the Roman numerals "IIII" to express four o'clock not the correct figure"IV"？
Two ways of writing the number 4 are admissible: IV and IIII. There are various historical explanations for this. It is known that IIII was used for over four centuries, to avoid confusion between IV and VI when the watch is upside down. Another theory has it that in the 16th and 17th centuries, IIII was used to make it easier to read the time for people who were illiterate. Finally, it can be seen simply as an aesthetic choice, since IIII representing a better balance with the VIII opposite.