U.S. patents covering time keeping mechanisms (1892)
United States. Patent Office · [Washington : United States Patent Office] · leaf 541
Ugfyd&V A -O A … u m TMC NOftPlS PETEflS CO. PHOTO-LITMO. WASHINGTON. I (No Model.) 17 Sheets—Sheet 8. G. E. HUNTER. MECHANISM FOR TESTING WATCH BALANCES AND HAIR SPRINGS. No. 490,202. Patented Jan. 17, 1893. St %X>7
Clocks and watches
Internet Archive · Smithsonian Libraries · Public Domain Mark 1.0. Free to use for anything.
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