This Day In Patent History – December 24 (Patent No. US 222,881 – A Improvement in magneto-electric machines)

This Day In Patent History - December 24 (Patent No. US 222,881 - A Improvement in magneto-electric machines)

This Day In Patent History – December 24

Improvement in magneto-electric machines
US 222881 A

Publication number US222881 A
Publication type Grant
Publication date 23 Dec 1879
Filing date 10 Sep 1879
Inventors Thomas A. Edison