Auction: Clocks, Watches & Scientific Instruments - 2502Location: MarlboroughDate / Time: May 01, 2010 10:00AM
Description:
Protracting Parallel Rule, William Helffricht, Philadelphia, the parallel rule with "S" hinges, lower section with engraved index, the upper engraved Wm. Helffricht Maker Philada, protractor engraved with degrees and index arm with vernier, maximum lg. 11 1/2 in.
Estimate $400-600
no significant repairs or replacements, instrument in old cleaned surface.