Scientific Medical & Mechanical Antiques
Site ContentsA bimonthly publication for the collector, dealer, and researcher Subscription Info
spec6

U.S. Patent No. 671420, April 2, 1901
A. Humphrey, Allegheny, PA

Claimed to strengthen the optic nerve, these spectacles had one copper and one zinc bow, each ending in a porous bulb containing an electrolyte.

other spectaclesother articles