Welcome to Continuous Wave, your home for essays, histories, and reflections on modern media (and magic?!) from the POV of audio — a project of story editor Julia Barton.

Last time, I wrote about the wireless era and what it has to teach us about listening. Today's edition explores something I ran across while researching that era: a weird proto-hacking incident that foretold pretty much everything about the world we live in now.

But first, I must issue a

~ PRETTY NERDY CORRECTION ~

In "Dialing It In," I mentioned a device, a “magnetic detector,” that inventor Guglielmo Marconi built from horseshoe magnets and wire to detect radio waves and translate them into sound. I then wrote about Marconi's infamous 1901 experiment to send Morse code messages across the Atlantic.

This implied that Marconi was using his magnetic detector when he heard (or thought he heard) Morse code for "S" in his headphones in Canada. In my confusion, this is what I thought he used. But in fact, that receiver did not exist yet — Marconi did not come up with it until 1902.

I learned this and more details about the magnetic receiver (aka "Maggie") from a book I just ran across in the Harvard library stacks.

Early Radio: In Marconi's Footsteps is a very out-of-print nerd quest by Australian radio enthusiast Peter R. Jensen. Jensen roamed the world, visiting Marconi landmarks but also trying to replicate his inventions.

To rebuild “Maggie,” Jensen truly did follow in Marconi's footsteps and even ordered a roll of thin florist's wire, as the inventor supposedly used in his prototype. Jenkins then used that wire and magnets to receive the sound of radio signals.

So what did Marconi use during his 1901 trans-Atlantic experiment? It was what's called a coherer — some metal filings in a glass tube that would react to the presence of electromagnetic waves. He later called it “crude.”

I stand corrected — just don't ask me how either receiver actually generates sound in a telephone earpiece. I did not become a podcast story editor by getting a PhD in physics! Or history for that matter.

While reading up on wireless days of yore, I ran across one of those incidents that makes history feel very now. It involves sabotage, Edwardian-era tech bros, and — what else? — rats.

This all went down in the summer of 1903 at the Royal Institution in London, where scientists and skeptics had been gathering for more than a century to show off their advances.

(Aside: this incident is also a short chapter in Erik Larson's 2006 popular history Thunderstruck — but being haphazard as usual, I only just found out about that book. It seems I'm relying on the same sources as Larson).

What Marconi and his right-hand man, the engineer John Ambrose Fleming, needed to show off in 1903 was proof that Marconi transmitters could and receive messages in private via tuned wavelengths.

This concept, known as "syntony," was already well-studied by 1903, but hard to pull off with the technology of the time. Marconi had basically tried to ignore the need for syntony, but as more and more people started building transmitters, it became clear that blasting out "dirty" electromagnetic waves on multiple frequencies only worked if no one else in the area was doing the same thing. That’s because conflicting signals tended to blot one another out.

It had also become clear that anyone with a nearby receiver could pick up wireless messages intended for others.

Marconi claimed he'd solved the problem by building antennae and receivers that worked on the same secret frequency. He and Fleming were going to demonstrate it with special transmissions to the Royal Institution during a lecture on June 4, 1903.

There was only one problem…Marconi’s #1 enemy, a magician and pro-grade hater named…