Archived posting to the Leica Users Group, 2000/09/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]In a message dated 9/15/00 8:19:03 AM Eastern Daylight Time, mano@proxyma.net writes: << When I bought my Tudor Submariner the dealer showed me an old Rolex information sheet which explained one should store a mechanical watch flat with face up to gain time, sideways with crown down to loose a little time, crown up to loose more time. Apparently gravity affects accuracy. >> Indirectly, it can. To understand how, visualize a watch movement, with the balance wheel plano-parallel to the plates which serve as the chassis. The balance is like a bicycle wheel, in that it is mounted on an "axle" known as the "staff", suspended between two carefully lubricated jewelled bearings or mountings, on points called "pivots". When the watch is on its back, the balance rests on the lower jewel. When it is stood on edge, it is suspended like a bicycle wheel during forward motion. As mentioned by another LUG'er, watches are factory "adjusted" so as to run at set rates in as many as 6 positions, although more are used, but very infrequently. The ultimate goal is to have the watch run as accurately as possible in actual use. Extreme precision is required, compared to, say, a mantel clock, which needs to run in only one position. An ideally adjusted watch will not show measurable differences in running rates in different positions. A well adjusted watch with little wear may not either, on a daily basis. But most watches are not operating optimally, let alone ideally. It is not gravity which alone changes the rate at which a watch runs, but a combination of physical forces which, among others, includes friction. Physicists or watchmakers receiving this post are welcome to correct my simplistic and probably inaccurate account! Joe Sobel