I’ve not written much on the history of mimeographs and other duplicating techniques, so you may or may not know the progression of inventions.
The prolific inventor Thomas Edison is to be credited for one of the first machines to allow a writer to make multiple copies of a document and the first electrically-powered (and battery-supplied) appliances with his “Electric Pen.”
The well-researched site Edison’s Electric Pen, created by Bill Burns — a duplicator aficionado from the UK who became active in the fanzine scene in 1964 and who went on to collaborate and create with a wide array of writers and artists (as evidenced by some of what’s to be found at his other site, efanzines.com) — is a fantastic resource for information on Edison’s invention. Bill has based the site’s information on primary material from The Thomas A. Edison Papers Digital Edition as well as other sources, and Edison’s Electric Pen includes schematics, samples of duplicated documents, a timeline, and data about the production and distribution of the machines. Of particular interest is the registry of all known surviving electric pens (currently forty-eight machines).
If you’re at all historically-inclined, do swing by Bill’s site and take a look. I’m particularly grateful for and heartened by others’ efforts to keep such historical information available.