Art in the Deep Freeze Petworth House: The Big Spring Clean

In an idyllic Sussex landscape, created by master gardener Capability Brown,

sits one of Britain's finest stately homes, Petworth House.

Thanks to the National Trust, it's now open to us all.

Except during winter when, like most of the Trust's homes, Petworth shuts the public out.

When the house is closed, however, it's far from quiet.

Normally, nobody gets to see what happens in here during the winter months. But this year,

I've been given unique access to see what goes on behind the scenes.

When the public have gone, the National Trust's expert conservation teams

get the chance to do some housekeeping, on an epic scale.

We get to see things up close that people don't see. It's amazing. Who else gets to do it?

I had no idea until I took on this task quite how filthy the visitors were.

And this winter, Petworth's got a new cleaner.

-I can see that I've made a difference.

-Have you waxed it?

-No.

It's a rare chance to get hands on with history...

Ooh, it's heavy!

..and glimpse the secret life of a great country house.

On this visit, I'm set to work in Petworth's en-suite art gallery...

take a turn round Britain's earliest globe...

and reveal the hidden identity of a 2,000-year-old Roman.

I'm joining perhaps the biggest spring clean in the world,

which all takes place during the freezing months of winter.

By January, Petworth House has been closed to the public for two months.

But no matter how cold it gets outside, inside, conservation work carries on.

Next on the winter schedule, the biggest and most time-consuming of all the rooms in the house.

Several generations of the family who lived here were keen art collectors.

So keen, in fact, they built their own gallery to house it all.

It may look more like public institution than private home,

but this sketch from the 1860s shows it could be playroom as well as museum.

We all like to have a few pictures on the wall, but this takes it to a whole other level.

Imagine growing up here. What a playground!

Over the coming three weeks, however, the North Gallery will be our workplace.

Petworth's six-strong housekeeping team will be joined by

other conservation experts to carry out a range of tasks.

Not just cleaning, but also scrutinising and investigating

the National Trust's biggest single collection of art and sculpture.

There's a dozen Turners in this room, as well as Gainsboroughs, and some rare works by William Blake.

But the first artefact that needs our care is neither painting nor sculpture.

House steward Susan Rhodes is about to reveal it to me.

The shutters are drawn and there's still another cover over this object

so it must be something that's really light sensitive.

-It is, yes.

-It's like the mystery object.

-Yes.

-What's inside?

-This is a fantastic, very early, rare English globe.

-Wow.

How early is early?

1592. It's the earliest English globe in existence.

This plastic cover comes off just once a year,

so the team can perform a close up check of the object's condition.

The globe came to Petworth thanks to the ninth Earl of Northumberland.

His love of learning earned him the nickname "the Wizard Earl".

According to family lore, he was given the globe by Sir Walter Raleigh

while both men were imprisoned in the Tower of London.

It's a rare object which the conservation team don't dust.

Made largely from paper, it's too fragile for even the lightest of brushes.

We still need to inspect it for damage, however.

We'll look all over globe and look for anything that looks fresh.

These big patches where things are missing are obviously old because they're discoloured and blend in.

Unfortunately, a lot of people have gone, "Here we are," and rubbed the UK away.

You can just see the west coast and you can see Ireland.

Of course, it's incredibly attractive for pests.

-It's been riddled in the past. Not the globe itself.

-Not the globe itself, but the stand is.

-Pests like to eat paper, don't they?

-They do, things like silverfish graze across it like cows.

Oh, I love this, have you seen on this side? Is that a sea monster?

Yeah, it's got different sea monsters in different areas.

Gosh, what a wonderful thing.

What is it makes this object so light sensitive?

It is the fact that it's paper, and you could lose that surface detail.

So in a sense, it's a huge, round drawing.

-Exactly, and it's just as fragile.

-And they have to be kept in the dark otherwise they fade.

For this inspection, we're briefly shining a working lamp on the object.

However, even the dimmest of ambient daylight can still cause

a photochemical reaction in paper, producing acids which attack its fibres, and fading coloured dyes.

The whole spectrum of light can cause damage, including ultraviolet.

-UV is the most dangerous type of light.

-I knew it was for skin, but I didn't know it was for objects.

Our skin is basically organic material. It's the same as paper.

All the windows in National Trust houses have a UV film on which you can't see.

It doesn't stop you from looking out, but just dramatically reduces the amount of UV that's allowed in.

But since any light causes some decay, the team must continually monitor levels.

With this, we can measure the amount of lux, which is what we measure light in, that's hitting the globe.

On an open day we would aim to keep it below 50.

Obviously our conservation lights, which are essential for the visual inspection...

You can't inspect it if you can't see it.

..dramatically increase the light. That is three times the light levels we keep it at.

The Trust also uses another less hi-tech tool.

This sits on the edge of the case on the globe all the time, so when it's uncovered, this is uncovered.

-This is a blue wool dosimeter.

-A blue what-ometer?

-A blue wool dosimeter.

This is a British standard blue wool which fades at a known rate.

So we leave it on there for the season, and then it's sent away to our conservators

who can then tell us how much light the object's had.

If we open it up you can just see the change in colour.

-That's quite striking, isn't it?

-It is. It's really different.

-That's a year's worth of fade, is it?

-That's a season's worth.

March to the beginning of November. It shows you why it's so important to monitor your light levels.

If we were open 365 days a year and ten-hour days, a lot of these objects wouldn't last as long as they will

with the restrictive opening times.

The statues we're working on have been housed here since the 1750s.

They are the reason the North Gallery was first created.

They were brought to Petworth by Charles Wyndham,

the second Earl of Egremont, a leading politician of his day.

Like every self-respecting English milord of the 18th century, the Earl had been on the Grand Tour

where he acquired a taste for all things Italian, all things classical.

And he pillaged half of Italy for his extraordinary collection.

When the second Earl bought these survivors from ancient Greece and Rome,

they were already up to 2,500 years old, and many were missing limbs, noses, even heads.

Taking the opposite approach to today's National Trust,

the statues were repaired by skilled sculptors in Italy or England.

For years, objects like this were turning up almost every month in crates here in West Sussex.

So many classical sculptures did he buy that art history is still only catching up

with the real story about a lot of the objects in Petworth's collection.

In the corner of the Little Dining Room, for instance,

is one which doesn't even rate a mention in the guidebook.

It's referred to merely as "young man in toga".

But there's an archaeologist who reckons this may be someone much more important.

A notorious figure from Roman history who's been hiding out in West Sussex.

In an attempt to uncover the sculpture's hidden identity,

Dr Miles Russell has come to analyse it in-depth.

-So here you go.

-Oh, fantastic.

-This is what you were after.

He's a little smaller than I expected,

but it's certainly mid-first century AD.

And that's the kind of pose, as well, of the young man, almost like a magistrate.

He's got official documents there, and he's standing in a pose waiting to speak to the Empire.

Miles has been searching for images of none other than the Emperor Nero when he was a teenager.

Such statues are extremely rare because Nero grew into such

a monstrous tyrant, nobody wanted to keep a marble souvenir of him.

There's a lot of damage to the neck. All the images we've seen of Nero

have been smashed after his death

as an attempt to eradicate him completely out of Roman history.

Or, there is a tendency in the 18th century to add bits, to reconstruct,

and that's something the scan will certainly pick out.

To reveal the truth about this statue,

the archaeologists have brought with them some technology more commonly used by the police in forensic work.

The face is the most important thing.

If you can get some nice clean images of that.

The laser scan builds up an extremely detailed 3D model,

every part of which can be compared with the only two statues of the teenage Nero which have survived,

one in Parma, the other in Paris.

Oh, that's fantastic, isn't it? That is brilliant.

You can see the eyes extremely clearly.

-That pouty mouth, and the chin, that is brilliant.

-His eyes have come up really nicely.

That chin, and the position of those lips, that's classic Nero.

That's him, isn't it?

The scan is of keen interest to house manager Andrew Loukes.

-How's it going?

-It's coming up brilliantly, actually, as you can see.

-So do we think it's him?

I think it almost certainly is.

It is early-to-mid 1st century AD.

The fact that it's made out of marble would suggest an important member of the imperial household.

The fact that it's a boy suggests it's a person about to achieve great things,

so all these things narrow it down until there's really only one candidate left.

What can you really tell by the scan that we couldn't really see with the naked eye?

The problem with looking with the naked eye is the way that shadow goes, the way that lighting goes,

whereas here, in the scan, you've done away with all the artificial lighting conditions,

-and you can see the eyes, you can see the crisp shape of the eyelids extremely clearly.

-Oh, you can.

-You can turn it from all directions. You can see the beginnings of a double chin there.

-Oh, yeah.

-Got into bad habits early, did he?

-Well, he did, yes, all that sort of imperial food in the palace.

-This is one of three complete young Neros.

-So it's incredibly rare.

-Yes, oh, yes, very much so, and incredibly important.

-Yeah.

-Congratulations.

-Thank you.

-We've won the lottery.

-Indeed.

It's a discovery of international significance, yet it's been hiding in plain sight for centuries.

This previously ignored statue can now be counted as one of Petworth's most important treasures.

The man who brought all these antique statues to Sussex, the second Earl of Egremont,

died suddenly in 1763, according to family legend, after one turtle dinner too many.

His son, the third Earl, presided over what's seen as Petworth's Golden Age.

In the 1820s, he extended the North Gallery to its present immense size.

He was collecting even more sculpture, though of a different kind to his father.

The third Earl laid down a challenge to the British sculptors of his day.

For years, they had complained there were no enlightened patrons.

Aristocrats only wanted portraits of themselves.

They had no chance to flex their muscles, to compete with the great Michelangelo.

So the third Earl said, "OK, if you think you can do it, carve me

"some monumental, classically inspired sculptures."

This is how John Flaxman rose to the challenge.

Begun in 1817, completed nine years later,

St Michael Overcoming Satan is over 11 foot tall.

Now it's the next thing I am supposed to be conserving.

I'm looking forward to this.

I think that this is, um...

..maybe the finest 19th-century British sculpture.

Certainly one of them. It's an absolutely...

How do you do, Archangel Michael?

What a great treat to see it from up here, from Archangel Michael's perspective,

staring down at Satan.

From up here, it looks as though Satan is about to plunge down into the abyss from the height of heaven.

The best thing of all is the way in which that foot of the archangel

goes underneath the arm of Satan,

and you can get this fantastic contrast between the smoothness of Michael's leg

and Satan's thick, heavy, veined forearms.

You can see that Satan has got blood coursing through his veins,

and that's such a difficult skill, to carve the veins proud like that.

The whole piece is carved from a single block

and it's an absolutely phenomenal, phenomenal achievement.

But of course, I didn't climb up here to rhapsodise.

I'm supposed to be cleaning. Even after half a winter, however...

there are aspects of conservation work I still find challenging.

There's no way putting on one of these hoovers with anything even resembling elegance if you're me.

It's actually covered in dust.

Petworth's statues are dry-clean only.

Washing could both remove the original colour and texture of the surface or stain the porous stone.

I am sorry about this, but I've been told to clean all of you.

It seems most indecent and very personal.

Oooh! I hope you're not ticklish.

This is the reality of working at Petworth.

The profane side by side with the sacred.

Such distinctions become irrelevant in the face of a greater, more permanent truth - dust.

Outside, temperatures are stuck below zero.

Inside, it doesn't feel much better.

Although Petworth House had heating installed in the 20th century, it's hardly ever switched on.

Why do we have to freeze? It's so cold in here.

It's not too bad. I mean, I have to be honest, I am wearing three layers,

-a gilet and thermals.

-You look like you've just stepped out of a chalet!

This is one of the main reasons we don't open to the public.

-It becomes unvisitable.

-Yes.

Visitors often assume it's uneconomic to warm a house on this scale in winter,

but cost is not the main reason why most historic homes have to be careful about heating.

The problem with heating a room too much is that it starts to dry out

and a very dry room means that paintings, their frames and their canvasses will start to crack.

What we're more concerned with here is relative humidity,

not temperature. That's how moist or how dry the atmosphere is.

Too damp an environment would also be a problem.

Wood can swell, metals corrode, and mould and insects become more likely.

So humidity levels throughout the house need to be controlled.

We have a band of 50% to 65%.

That's the amount of moisture that we like to keep in the objects so they are at a stable condition.

In the summer, do you turn have air conditioning to make it cooler?

In the summer when it's warm, the heating often comes on...

-Great(!)

-It's quite humid in the summer and so the way of taking that moisture away is to dry...

Oh, you disperse? Oh, I see.

-We boil in the summer and freeze in the winter - all in the name of art?

-Exactly, all in the name of art.

The masterpieces of Petworth aren't just made of stone and canvas, of course.

Some of the furniture here can definitely be counted as art in its own right.

Sue and I are about to clean a commode from 1710,

when that word meant low cabinet rather than toilet.

It's in a style found throughout Petworth. Boulle work.

What's special about this item is that Andre Charles Boulle himself built it.

-This is my favourite thing in the collection. I think it's beautiful.

-This is your favourite piece?

-My favourite out of the whole house. It's just a stunning piece.

-Wow.

It's tortoiseshell inlaid with brass.

The brass is dulled down over time,

but it would have been a shocking contrast against the dark of the tortoiseshell.

-And is it possible now to bring it back?

-It would be possible, yeah.

It's just the tarnish and dirt that's built up over the brass, but, this is part of this piece's history now,

and the Trust has a policy of consolidating condition rather than restoring to new.

Gosh. I must say, in the case of something like this, I wouldn't agree with that

because the aesthetic affect of the object has been compromised.

It's one of those ongoing arguments with the Trust and the general heritage industry.

You have to think that this piece is part of an interior scheme, and you have to think of the tonality.

If you restore this to new-looking, it would then offset against the Turner frame above it,

-which would then offset against the walls.

-Nah, I don't agree.

'Unmoved by my opinion, Sue gets on with the cleaning she is allowed to do.'

I'm going to start here on these fantastic ormolu sphinxes heads.

-She's a sphinx?

-She is.

Andre Charles Boulle is clearly flattering Louis XIV

by comparing them to these mystical creatures of wisdom and knowledge.

And these deposits in here, that I can see?

Again, this is where dust has built up over time. We won't get this off.

This isn't coming off with a brush. Once it kind of gets to this point

where it's proper ingrained, this is historic dust, so it's almost...

-Historic dust!

-Historic dust!

One of the amazing things about the construction of this piece is it's so well made

that it is airtight inside and has its own kind of micro-climate within the piece,

which causes us problems because it gets too humid in there, too damp,

and we get mould growth inside and on the drawers - which you can see - and we're going to take that off now.

'Clearly this is one of part of the object's history that the Trust doesn't feel the need to preserve.

'To keep mould at bay, the team generally leaves the commode's drawers open

'when visitors aren't around.

'That way, they're kept ventilated.

'The marble top is cleaned with the usual mix of water and sensitive skin washing-up liquid.

'Once rinsed and dried, it's coated with wax.

'Unlike the beeswax used on wood, or the paraffin wax used on floors,

'this is a petroleum-based microcrystalline variety, which makes it both finer and denser.'

We wax the surface of the marble tops because it gives it a protective layer during a busy open season.

Most people might be quite surprised to learn that marble's actually incredibly porous.

This just stops the dirt and dust that's going to fall on it from getting ingrained in the surface.

I like these rather gormless Turner sailors, looking at you. "What's she doing down there?"

So many of our visitors are so busy staring at the Turner that they forget the furniture underneath it.

The rest of the team have been busy checking and dusting

the North Gallery's 107 paintings and frames,

which isn't the easiest of tasks if they are hung 20 feet high.

Sometimes outside specialists join them to carry out more in-depth conservation.

Sophie Reddington's come to care for one of Petworth's Gainsboroughs.

During my painting survey a couple of years ago,

I established this painting hadn't been touched

for a very, very long time - decades.

-So it's a general 25 years' service?

-It is, exactly.

Oh, I can see some lifting paint here, all along the bottom edge.

-Oh, yes.

-We'll have to do something about that.

The flaking was probably caused by changes in humidity

in the days when the gallery used to have the central heating on.

The first stage of treatment is to glue the flaking paint back down.

It's a very liquid glue with a low viscosity

which means that it sinks into the layers quite easily.

It can flow nicely

into the cracks.

I'm rolling a cotton wool swab, which I moisten with a little of my saliva,

to remove the excess glue from the paint surface.

Now I'm taking a piece of Bondina, which is a sort of non-stick paper,

and I'm trying to iron the paint to flatten it again.

The paper reduces the risk of the paint being damaged.

This is a specially developed heating spatula.

I can still easily touch it with my hand.

It's really just to introduce a little bit of warmth

to help the glue flow better between the layers.

Many decades ago, this process was actually carried out with ordinary kitchen irons.

It sounds very housewifey!

I don't really like ironing, to be honest.

I'm leaving it under weights for a while

because the glue is not quite dry yet,

and I'm moving onto the next section.

What Sophie's doing here is another example of the National Trust's

preference for conservation rather than restoration. She's not trying to make the painting look brand new.

Instead, just like the Petworth regulars, her goal is to preserve current condition.

That requires her to pay more attention to the frame than most visitors probably give the picture.

She has to clean places no-one else ever sees, because dust can attract insects or mould wherever it lurks.

The back needs some minor repairs, so Sophie calls upon another of her many skills...

carpentry.

The main thing to avoid is just really drilling through the canvas.

That would be an absolute awful thing to happen.

That's why I have chosen a very thick piece of board

to make sure I'm safe.

Then it's time to give the surface of the painting a clean.

The house team only get to dust, but Sophie is allowed to wash.

The amount of water I'm introducing onto the paint surface

is actually very minimal,

because if I were to use too much water,

then I could actually affect the surface in a really bad way.

The varnish might blanch, crack into really sort of fine, hairline cracks.

What little water Sophie does apply has had any corrosive mineral content removed by de-ionisation.

This dirt is surface dust.

In this case, plain de-ionised water seems to do the trick.

But sometimes you need far stronger cleaning agents to be able to remove old dust and dirt.

This is a very personal, romantic landscape by Gainsborough from the mid-1770s.

It was much admired by another of the artists who stayed at Petworth during the third Earl's era.

None other than John Constable.

-It's done. I finished it.

-It looks a lot cleaner.

I really feel like it has cheered up a bit.

Those swabs really indicate how much dirt there was on the painting.

-There's more colour in it, it's just generally lifted.

-Yes.

-Terrific.

Service and MOT complete, Gainsborough's put back

on Petworth's walls, where he's hung for nearly 250 years.

After three freezing weeks, work in the North Gallery is complete.

They may now look like ghosts, but I've learned

that all of these statues are, in a sense, very much alive.

Every one has its own story of how it came to be here and how it needs to be cared for.

And one statue above all really sums that up.

I do think it's an extraordinary story.

I mean, this is really Petworth House's Antiques Roadshow moment.

This rather overlooked sculpture in the corner of the room, object number 55, boy with a toga,

suddenly turns out to be one of the most precious, one of the most rare objects in the whole collection.

From zero to Nero.

It's a measure of just how incredibly rich the collections at Petworth House are,

that they can contain a revelation like this.

And it makes you wonder how many other surprises may lurk elsewhere in the house.

Goodnight, Master Nero.

Subtitles by Red Bee Media Ltd