Pocket watches consist of a circular face and three hands that complete a full revolution at different rates: the second hand takes 60 seconds, the minute hand takes 60 minutes, and the hour hand takes 12 hours.
There are 60 seconds in one hour, so in one hour the minute hand has completed a single revolution.
Circles contain 360 degrees so the minute hand, by completing one circle, has traveled 360 degrees after one hour.