In this box.

There are some souvenirs of my grand farmer.

The discharge is because they are tubes were electrical discharge.

I'll just show you this one because it stands up.

You can see it's a piece of quite ornate glassware on dhe.

If you look there, number of features that you can see it has bean sealed off here and here by putting a talk so it was sealed with a vacuum or gas in it.

And there's a narrow tube going inside, which goes round and round and round.

So and then they used to be an electrode at the top.

Now there's just a bit of wire, and there's an electrode at the front.

This is an example of what is called a Geisler tube named after a German physicist.

Come Geisler, who invented this in 18 57.

It belonged with the other two.

To my grandfather, my grandfather, who was called Joseph Polyakov, was an extraordinarily talented inventor he had.

I don't know how many patents in his lifetime.

He invented the volume control, which is now on every radio.

He invented the hearing loop, which helps deaf people here in concert halls and so on, and lots of other things as well.

He also invented an early form of the transistor in the 19 twenties.

But why he had these, I don't know.

I think he probably just thought they were fun.

And if you look at the glass, the glass is slightly yellow because it's impregnated with some sort of iron, which flew.

Rest is when exposed to UV light.

The point about these Geisler tubes is that they're filled with the low pressure of gas.

Unfortunately, I don't know what sort of gas.

It's definitely not neon because neon Woodley read it.

Maybe air.

It could be a Rh with the trace of mercury, But the important thing about these gases are that when you apply ah, high voltage.

A Neal used a device called the Tesla Coil, named after the famous scientist Tesler, which produces a very high voltage at a very high frequency.

It's sufficiently high that it can jump across narrow gaps of insulators like air on what is to me even now remarkable is that if you played them to these, you get to discharge to generate a plasma in the gas without having to have any electrical connection to the other electrode.

Presumably there is enough current that will leak either through the glass or to her through the air.

The mechanism is the high voltage ein eyes is the gas.

The irons re combine and give out energy.

This makes the guests hooked, and that emits light.

Not necessarily just because it's hot bit, because the electron as it falls back to the nucleus or to the energy levels, which it normally occupies, gives out light.

So it's a way of generating light right, and the particular gas will give a particular wavelength of light.

I don't know what this is.

Maybe a Rh even and the reason, I don't know, get a characteristic discharge from a gas, which depends on the identity of the gas and the pressure.

And since we don't know the pressure and we don't know the gas, it's a bit difficult to guess.

There are measurements we might be able to do but we might damage the tubes.

And anyway, we don't have the kit at the moment.

This equipment must be quite old because my grandfather, if he was still alive, would be 143 years old, and he died 55 years ago.

So the very minimum is probably 70 or 80 years old, could be 100 years old.

So the gas has been sealed inside the dolls for that time on.

The fact that they still work means they're still a low.

Pressure on air has not gone inside the tube from outside.

Everything leaks slightly, but the rate of leakage is so slow that the performance has not been affected, and I find that pretty remarkable.

Thea other thing, which you can tell, is that because the glass on DDE, the liquid here glow when the discharge takes place, it means that the gas is admitting UV light.

So presumably the tube going through here is either glass that does not absorb UV light for it strongly.

It could be quite thin glass, or it may even be courts there if it's quartz.

It's a fantastic piece of glass blowing because courts is not an easy material to blow.

I have once tried using this.

I can't remember when when we used to have Tesla coils in the lamp, but I haven't used it for 20 or 30 years.

That the minimum.

But then I thought that Neil would like to get his hands on it, and I wasn't wrong.

What to me is remarkable is that these pieces of equipment which have made purely for entertainment they have no deep scientific value and were made to entertain audiences perhaps 100 years ago are still working today and are still entertaining people, perhaps entertaining you definitely entertaining me but also oppose intriguing questions.

What is the liquid?

What is the glass made off and so on?

And of course, what immediately comes to mind is what techniques you could find to identify these things without damaging the equipment.

I think that my grandfather would be quite amused.

I knew him, though he died when I was 11 but I think it would be very amused that it was being sewed into such a big audience.

He couldn't possibly have imagined the number of people that would watch this video, even if it's not very successful.

We're talking about thousands of people watching it on DDE.

So I think it is really quite a a tribute to my grandfather that the items that he collected and now being shed with a big audience.