A few fun gadgets:
Multi-Speed Pentron Tape Recorder
Here's a recording device that would fit in perfectly with the first season of Mad Men. It's a Pentron reel-to-reel tape recorder, produced during the 1950s.
Pentron marketed their tape recorders for family use (because what could be more entertaining than letting the kids record their voices on an expensive new gadget?), but probably proved more useful for business meetings.
The Pentron Corporation was based in Chicago. Their slogans included "In Electronics... It's Pentron" and "There's more fun at home when you have a Pentron."
You can never have too many voltmeters. What, you haven't got even one? Well, now's your chance to load up!
Most of these voltmeters were produced by Weston Electrical Instrument Corporation of Newark, N.J., probably during the 1920s or '30s. One exception is the red voltmeter, which might have been made during the 1890s.
Some of you may be too young to know what this is. Before the dawn of computers and PowerPoint, people used actual physical slides that were projected through machines like this Argus 200 slide projector.
Before electricity, slides were projected using kerosene lamps inside of magic lanterns. This "Lanterne Magique" was produced by Ernst Plank, and is unfortunately missing a few parts (but is still super-cool!).