You have two pieces of metal -- copper and zinc --

which you connect to conducting wires.

And you then submerge the metals in an electrolyte --

in this case vinegar.

You will observe that bubbles will form

around the zinc --

but not on the copper.

The metals seem dissimilar in this way.

If you then connect the two wires holding the metals,

something changes.

Tiny bubbles begin to form around the copper terminal!

It seems as though something is being pulled from the zinc,

through the wire,

allowing a reaction to occur on the copper side.

And it turns out this is a flow of electrical charge,

as electrons are pulled away from the zinc

towards the copper

through the conductive path in the wire.

We can think of this flow

as the result of a charge imbalance,

or electrical pressure between the two metals --

as compared to the instantaneous discharge observed

with static electricity experiments.

Towards the end of the 18th Century,

Alessandro Volta had been investigating this effect.

More importantly, he found chaining

these cells together --

would amplify this flow of charge.

By 1800, he simplified things even further,

removing the jar,

which provided more electrolyte than was actually needed.

He writes:

"[using] a few dozens of small round disks of copper

(pieces of coin for example)

and [an] equal number of plates of zinc,

I prepare circular pieces of spongy matter

capable of retaining a water,

"I continue coupling a plate of copper with one [of[ zinc,

and always in the same order,

and interpose between each of these couples

a moistened disk.

This continues until I have a column as high as possible,

without danger of it falling."

This is known, famously, as the "voltaic pile" --

the first battery in history to provide

a continuous flow of electrical charge -- or current.

More cells resulted in an increased

electrical pressure at the two ends.

And "electrical pressure" was an early term

for what we now call "voltage" -- after Volta.

If the two leads of a voltaic pile were brought into direct contact,

a series of shocks could be observed.

At first, the utility of electric current

as a communication method

was not immediately obvious,

aside from faint sparks and bubbles.

One idea was to use the presence of bubbles

to signal letters.

The bubble telegraph used this method,

though it involved 26 difference circuits -- one for each letter.

It was based on the fact that the battery providing the current

can be placed at a distance,

away from the jars containing

the leads creating the bubbles.

An inventive, although clumsy system,

which was never adopted.

But very soon, everything changed,

after a famous demonstration in 1819.

It was found that if we simply pass wire near a compass,

and connect it to a battery,

as soon as the wire made contact with the battery,

the needle jumped -- without any physical contact!

The only explanation was that

the current-carrying wire was creating

a temporary magnetic field!

This was followed by a series of tests

to figure out the direction of this field.

First, we assumed it to be pointing along the wire with the current,

or outwards from the wire as heat would travel.

Eventually, it was determined that it must travel around the wire --

in perpendicular circles.

So a loop of wire would create a magnetic field

which points through the center of the loop,

and around the outside.

This led to the galvanometer,

which was designed to detect and measure electric current.

It was simply a coil of wire with a compass needle in the center.

When electric current was applied the magnetic field,

the needle would always point

perpendicular to the direction of the force,

which was balanced on either side of the needle.

The stronger the current,

the stronger the deflection of the needle.

By 1824, William Sturgeon demonstrated a way

to increase the strength of this field even more.

Simply by wrapping a coil of wire around a piece of iron,

such as a nail, the magnetic force could be amplified.

Iron seemed to be a better medium

for supporting the formation of magnetic fields --

in the same way that heat travels better through metal,

than through air.

We call this "permeability."

And by wrapping the wire many times,

the strength of the field could be amplified thousands of times.

-- known as an "electromagnet."

Suddenly, it was possible to create magnetic fields

which could move needles with precision and force,

using an electric current applied at a distance.

instantly, over a long distance was possible,

With these new technologies,

the race to change the way the world communicates was on.

What were we racing towards?

At the time our understanding of information was in its infancy.

People were thinking about information in a message

as the number of letters in a message.

So the goal was intuitive -- who could come up with

the fastest way to transmit letters?

Whoever had the fastest system would,

therefore, reduce the cost per message

for the sender using the system.

A gold mine was waiting for whoever got there first.