Vibrating hair spring. Hair spring is placed into a vibrating machine and operator selects the hair spring with an elastcity which would vibrate a balance wheel with period of 18,000 times per hour, 1936
| Uploaded by | U.S. National Archives |
|---|---|
| License | No known copyright restrictions |
| Comments | 0 |
| Favorites | 7 |
| Views | 12,143 |
| Date taken | 1936 |
| Date uploaded | 2012-07-03 |
| Tags | nara:arcid=518442, usnationalarchives, lewishine, thegreatdepression, lancaster, pennsylvania, 1936 |
| Visibility | public |