as the radio likely had a cat whisker detector in it.

That thing looks like you'd need a degree in electronics just to use it.

This photo prompted me to learn a bit online about the Freed-Eisemann company. Here's a contemporary picture of that same radio, the "Marvel" model:

http://kensradios.com/crystals2007010808.htm

Freed Eisemann enjoyed a tremendous sales bonanza with its Marvel crystal radio, introduced in 1921. The radio required a long-wire antenna and a good earth ground connection and was powered by the radio station's signal.

Listening to intergalactic news broadcasts from outer-space isn't a new hobby. I have never required a battery to amplify the volume but do find a tin-foil cap handy in silencing the programs when I wish to sleep.

If that poor dog has to listen to her sing "Amani Alfredo"
one more time he's gonna croak!

When I first looked at this, I thought they were hooked up to a buzz coil, (used to make ignition spark in engines). The Eisemann Company did make ignition systems. Whatever the box is, I don't believe it is a radio.

[You're confusing the Eisemann Magneto Co. with Freed Eisemann Radio Co. The apparatus in the photo, as a quick Google will reveal, is a F-E Marvel crystal set. - Dave]

Of course, the picture was a "photo-op", and no sound was actually delivered into the headsets. The set needed an external antenna and none is visible.

[Look again, and follow the wires. - Dave]