0:00:30 > 0:00:33Wexford.
0:00:36 > 0:00:39To the Vikings, Waiesfjord.
0:00:39 > 0:00:41A wide shallow harbour.
0:00:41 > 0:00:46To another invader, Oliver Cromwell, the town of Wexford was a Catholic thorn in his side.
0:00:49 > 0:00:52In 1649, his New Model Army wiped out all Catholic resistance
0:00:52 > 0:00:59and replaced them with a new wave of settlers, the so-called New English.
0:01:01 > 0:01:06The town is one thing, but he who would be master of Wexford's harbour
0:01:06 > 0:01:10must do battle with a constant natural foe.
0:01:10 > 0:01:11Sand.
0:01:14 > 0:01:21As the tide ebbs, the entire estuary is filled with continuously shifting ridges of sand.
0:01:26 > 0:01:31Deep-draughted ocean-going vessels can't cope with the perils of the sandbanks.
0:01:31 > 0:01:34But there is a very ancient type of boat that can.
0:01:34 > 0:01:41Flat-bottomed, and traditionally with a pointed bow and stern, it's the Wexford Cot.
0:01:41 > 0:01:47Larry Duggan is my name, and I have been making Wexford Cots for 60 years, of all types.
0:01:47 > 0:01:53Our whole family have been in it for hundreds of years, father and my grandfather,
0:01:53 > 0:01:57and my great-grandfather, great- great-grandfather were making these
0:01:57 > 0:01:59in the early part of the 18th century.
0:01:59 > 0:02:05I suppose it's nice to be able to say that you're able to do something that comes natural to you.
0:02:05 > 0:02:07That's quite good now, Richard.
0:02:07 > 0:02:10Wexford's the only place that we get cots.
0:02:10 > 0:02:13It's the estuary that makes the cots suitable for what it is,
0:02:13 > 0:02:16or the cot is suitable for the estuary, however you want to put it.
0:02:16 > 0:02:20That boat would push out in six inches of water.
0:02:20 > 0:02:24You wouldn't get near the beach with a keel boat -
0:02:24 > 0:02:27the keel would be in the mud before you get near the shore.
0:02:27 > 0:02:30That's clinker. Clinker is one board lapped over another.
0:02:30 > 0:02:34I think the Vikings brought that to this part of the country,
0:02:34 > 0:02:40because all the Viking boats are all clinker-built. Apart from the cots I've made shooting punts.
0:02:40 > 0:02:45I became an expert on building punts - no matter who wanted a punt, they came to Larry's yard.
0:02:48 > 0:02:52Traditional punt is only ten inches high and she's 15, 16 or 17 feet long.
0:02:53 > 0:02:55You push it along with a pole.
0:02:56 > 0:03:00A good punter turns on his side this way, and he's able to just glide along.
0:03:00 > 0:03:08It's loaded from the muzzle, usually six ounces of shot to every ounce of powder.
0:03:08 > 0:03:13And my big one takes four ounces of powder, 24 ounce of shot.
0:03:13 > 0:03:15GUNFIRE
0:03:15 > 0:03:17When it comes to the good shots,
0:03:17 > 0:03:19there have been hellish good shots.
0:03:19 > 0:03:23I got 166 golden plover in one shot...
0:03:23 > 0:03:25way back in 1952.
0:03:27 > 0:03:32There was a great market for them. I mean, all during the war years you couldn't get enough of them.
0:03:32 > 0:03:36England, that's where they were all going, to feed them all in the war.
0:03:40 > 0:03:43Shooting wildfowl using a punt can be lethally effective.
0:03:43 > 0:03:48But it's also licensed and very strictly controlled.
0:03:48 > 0:03:53Out of range of ancient gunshot, on the north side of Wexford Harbour lie the Wexford Slobs.
0:03:53 > 0:04:00Now, slob is simply the Irish word for muddy land, which this entire area was until the 1840s,
0:04:00 > 0:04:02when it was drained and reclaimed.
0:04:02 > 0:04:08For the past 30 years or more, around 500 acres of slobland have become a wildlife reserve
0:04:08 > 0:04:13and over wintering site for a huge variety of wild birds,
0:04:13 > 0:04:19and as Wexford sleeps, Miranda's going in search of one very special species.
0:04:39 > 0:04:43It's about an hour before first light, and Paddy and I
0:04:43 > 0:04:45are setting off to a place called Raven Point
0:04:45 > 0:04:47at the north end of Wexford harbour.
0:04:47 > 0:04:50If we're very lucky, we might just catch a glimpse of
0:04:50 > 0:04:54a rare and very beautiful visitor to this part of the Irish coast.
0:04:54 > 0:04:56Lights out?
0:04:58 > 0:05:03My guide out to Raven Point is wildlife warden Paddy O'Sullivan.
0:05:03 > 0:05:09Apparently, our success is going to rely on keeping chat and movement to a minimum.
0:05:09 > 0:05:12I wish I'd bought a flask of tea.
0:05:12 > 0:05:20Suddenly, out of the darkness, an unforgettable call - "nedleck, nedleck",
0:05:20 > 0:05:25and against the early morning sky long strings of silhouetted birds start to appear.
0:05:28 > 0:05:30Magical. It's brilliant.
0:05:35 > 0:05:39Fantastic, just the sheer numbers of them,
0:05:39 > 0:05:43the beauty of the call.
0:05:48 > 0:05:52You can even hear the hum of the wings. This is just magical.
0:05:52 > 0:05:58This is probably the best spot to be, because right here you get over a third of the world's population
0:05:58 > 0:06:00of Greenland white-fronted geese.
0:06:03 > 0:06:06BIRDS CHATTER NOISILY
0:06:13 > 0:06:17It's now 7:30am and it's a real November morning.
0:06:17 > 0:06:22These birds have spent the night out on freezing cold exposed sandbanks.
0:06:24 > 0:06:30Now, in the safety of daylight, it's time for a hearty breakfast in the nearby stubble fields.
0:06:35 > 0:06:39For me, a day in the life of the Greenland white-fronted geese has just begun.
0:06:42 > 0:06:46Getting closer to them, one of the more obvious questions is answered -
0:06:46 > 0:06:50why they're called white-fronted geese.
0:06:50 > 0:06:53Their need to feed is paramount now.
0:06:53 > 0:06:56Each and every one of these birds has flown here all the way
0:06:56 > 0:07:01from their breeding grounds on the west coast of Greenland,
0:07:01 > 0:07:06an incredible calorie-busting journey of over 1,800 miles.
0:07:10 > 0:07:15'For some years, the Wildlife Trust's scientific officer Alyn Walsh has observed a marked decline
0:07:15 > 0:07:20'in Greenland white-fronted geese overwintering on the Wexford Slobs.
0:07:20 > 0:07:23'And there's only one way of recording the numbers.'
0:07:23 > 0:07:28Two, four, six, eight, ten, two, four, six, eight, 20, two, four, six, eight, 30...
0:07:28 > 0:07:35'Alyn and the team are extremely anxious to monitor the decline, and they repeat this wild goose count
0:07:35 > 0:07:39'time and time again during the winter months to collect accurate data.
0:07:41 > 0:07:48'It's a vast area, so we need to drive and the cars also act as a mobile hide.
0:07:48 > 0:07:52'The geese don't seem fazed by our vehicle.
0:07:52 > 0:07:59'But if we got out, the entire flock would be airborne in seconds and we'd have to start counting again.'
0:07:59 > 0:08:02Several of the geese have got neck collars.
0:08:02 > 0:08:06There was a "K9Z", and a "K5U". Do we know anything about those birds?
0:08:06 > 0:08:09Yes, K9Z and K5U have been together for a number of years now.
0:08:09 > 0:08:11I don't think they've any goslings this year,
0:08:11 > 0:08:15- but they probably will in very soon. - So, they're a breeding pair?
0:08:15 > 0:08:19They're a breeding pair, and that's sort of typical because we know that
0:08:19 > 0:08:22pairs are not producing young until at least their sixth year now.
0:08:22 > 0:08:26When you get to know the geese you can see that they're actually
0:08:26 > 0:08:29broken up into very discreet little family groups.
0:08:29 > 0:08:32If we look at this group here in the field, you can see there's a group -
0:08:32 > 0:08:34they're almost certainly related.
0:08:34 > 0:08:39- So both on the ground and in the air they stay within a family group? - Yeah. Normally,
0:08:39 > 0:08:42if they fly from one area to another, it's for water.
0:08:42 > 0:08:47If they're grazing, they would definitely have to have water every two to three hours.
0:08:47 > 0:08:51They eat a lot of vegetative matter, and because their digestive system is poor,
0:08:51 > 0:08:53they poop every three minutes.
0:08:53 > 0:08:56Now, I only came here to see the geese,
0:08:56 > 0:08:59but it's clear you've got a huge number of bird species
0:08:59 > 0:09:02that are travelling here from all over the place.
0:09:02 > 0:09:05The white-fronted geese don't have it all to themselves.
0:09:05 > 0:09:08Wexford is a very special place.
0:09:08 > 0:09:12It's like an international airport, a hub for a huge range of species.
0:09:12 > 0:09:16We've got in excess of 200 species that come to Wexford.
0:09:16 > 0:09:18Probably the most notable ones would be Brent.
0:09:18 > 0:09:24We have 3,500 Brent that come from the High Arctic of Canada.
0:09:24 > 0:09:26We have Hooper Swans from Iceland,
0:09:26 > 0:09:31we've got Snipe which again come from Iceland and from Europe.
0:09:31 > 0:09:34We've got Wigeon which can come in from Siberia,
0:09:34 > 0:09:38Golden Plover from Iceland, and Curlews that come Europe as well.
0:09:41 > 0:09:47By late afternoon there's a change of mood on the Wexford Slobs, a new sense of anticipation.
0:09:57 > 0:10:00There's a stirring amongst the geese.
0:10:00 > 0:10:03A quick shake of the head mirrored by other family or group members
0:10:03 > 0:10:06is a clear indication of an intention to fly.
0:10:13 > 0:10:18Soon family after family, squadron after squadron of geese
0:10:18 > 0:10:22from across the entire 2000 acres of Wexford Slobs
0:10:22 > 0:10:26is airborne and heading back out to sea for the relative safety
0:10:26 > 0:10:28of the Wexford sandbanks.
0:10:43 > 0:10:45Greystones, where the Wicklow hills
0:10:45 > 0:10:49dip a mountainous granite toe into the Irish Sea.
0:10:49 > 0:10:53Here, engineer Dick Strawbridge is exploring one of the most remarkable,
0:10:53 > 0:10:57but little-known achievements of one of his heroes.
0:10:58 > 0:11:02Engineers don't get much greater than Isambard Kingdom Brunel,
0:11:02 > 0:11:05and one of his greatest challenges was here on the Irish coast.
0:11:05 > 0:11:08Imagine trying to build a railway through that!
0:11:10 > 0:11:12TRAIN HORN
0:11:12 > 0:11:15Bray Head.
0:11:15 > 0:11:19Precipitous granite cliffs to tunnel through, deep gorges to cross.
0:11:23 > 0:11:27Railway engineer, Michael Barry, has no doubts as to the formidable
0:11:27 > 0:11:31obstacles Brunel faced, or to the brilliance of his solutions.
0:11:31 > 0:11:33I would call it heroic engineering.
0:11:33 > 0:11:39We have ramparts out over the sea, which have to stand up to the heavy waves.
0:11:39 > 0:11:44The rock is extremely hard, it was extremely difficult to tunnel,
0:11:44 > 0:11:50but it also is unstable and you get rock falls from time to time.
0:11:50 > 0:11:57Digging through that kind of rock, it would be a really very difficult engineering job to do it today.
0:11:58 > 0:12:06Since it opened in 1855, generations of engineers have re-routed, re-built and altered sections
0:12:06 > 0:12:12of the railway line through and around Bray Head, but you can still find evidence of the master's work.
0:12:12 > 0:12:15Down there you can just see some old stone piers.
0:12:15 > 0:12:18That's all that's left of Brunel's once-elegant bridge work.
0:12:20 > 0:12:26This was just one of the aerial bridges he built to cross a void, giving passengers an all too real
0:12:26 > 0:12:29sensation that there was little between them and the sea below.
0:12:29 > 0:12:36This wasn't a railway, it was a rollercoaster, and inevitably the thrills led to spills.
0:12:36 > 0:12:41On the 23rd April 1865 the 1st class carriage of the Dublin train simply left the rails
0:12:41 > 0:12:45and teetered on the edge of the viaduct 100ft above sea level.
0:12:47 > 0:12:52The driver kept his nerve and pushed on, pulling the carriages from the brink.
0:12:52 > 0:12:56But two years later, two passengers did die
0:12:56 > 0:13:01and 20 more were injured when three carriages left the rails and fell 30ft from one of Brunel's bridges.
0:13:01 > 0:13:05But the bridges weren't the only part of his line to take a battering.
0:13:07 > 0:13:09Bray Head's unstable rock fell so often,
0:13:09 > 0:13:14the company began selling it to contractors laying Dublin's roads.
0:13:14 > 0:13:16And the sea took its toll too.
0:13:16 > 0:13:20Storm damage was all too frequent.
0:13:26 > 0:13:30Brunel's railway through and around Bray Head proved
0:13:30 > 0:13:36so horrendously expensive to build, rebuild and maintain, it's even been called Brunel's Folly.
0:13:36 > 0:13:40But, in defence of my engineering hero, I have this one thing to say.
0:13:41 > 0:13:43It is a cracking ride.
0:13:53 > 0:14:01As we emerge from the tunnels we get our first glimpse of what's been nicknamed Ireland's Bay of Naples.
0:14:01 > 0:14:04Framing the scene is Killiney Beach,
0:14:04 > 0:14:11where Hermione is uncovering the story of a remarkable man and a revolutionary experiment.
0:14:13 > 0:14:18In the autumn of 1849, a group of workmen came down to this beach
0:14:18 > 0:14:20on an extraordinary mission.
0:14:20 > 0:14:24They'd been set the task of creating an earthquake.
0:14:24 > 0:14:28Now this earth-shattering plan was the brainchild
0:14:28 > 0:14:32of Victorian businessman and scientist, Robert Mallet.
0:14:32 > 0:14:37Robert Mallet was a Dublin-born scientist whose experiments on
0:14:37 > 0:14:41this tranquil beach began to explain the inner workings of the earth.
0:14:41 > 0:14:48Mallet founded a science and christened it seismology, the study of earthquakes.
0:14:48 > 0:14:54Nearly 160 years after Mallet created an earthquake on this beach,
0:14:54 > 0:14:56we're going to try the same thing.
0:14:58 > 0:15:03At a time when no-one really knew what caused tremors in the ground,
0:15:03 > 0:15:07Mallet wanted to test his revolutionary new theory that potentially
0:15:07 > 0:15:12devastating amounts of energy travel as waves through the earth.
0:15:12 > 0:15:19In the experiment, he blew up 25lbs of gunpowder at one end of the beach. His earthquake.
0:15:19 > 0:15:24Precisely half a mile away, he positioned himself with specially made equipment
0:15:24 > 0:15:30to see if shockwaves would register and how long they took to reach him from the explosion.
0:15:30 > 0:15:34Mallet's ambition was to pinpoint and map the epicentre
0:15:34 > 0:15:39of all the world's earthquakes and, if possible, save lives.
0:15:41 > 0:15:44Given there are several hundred small earthquakes every day,
0:15:44 > 0:15:48and a major earthquake every 18 months or so,
0:15:48 > 0:15:53Mallet's ambition is shared around the world to this day.
0:15:53 > 0:15:56But in paying homage to Mallet's original experiment,
0:15:56 > 0:15:58I've hit a few snags.
0:15:58 > 0:16:03Everyone's been lovely, the local authority, the Gardai, the Irish Police.
0:16:03 > 0:16:08But, well, they don't want their beach blown to bits, so I've had to scale things down
0:16:08 > 0:16:14to two kilograms of plastic explosive, and retire to a safe distance of 100 metres.
0:16:14 > 0:16:16And there's another but, and it's a big one.
0:16:16 > 0:16:22As if explosives weren't enough for us to cope with today, we've also got to deal with this.
0:16:23 > 0:16:26Mercury.
0:16:26 > 0:16:30Now, mercury is wonderful stuff, but extremely poisonous,
0:16:30 > 0:16:33so that's why we've got it sealed inside this dish.
0:16:33 > 0:16:38Robert Mallet's apparatus involved projecting cross-hairs onto
0:16:38 > 0:16:41a pool of mercury which he viewed through a microscope.
0:16:41 > 0:16:46If his theory was right, he could time and record how long it took for
0:16:46 > 0:16:51energy waves from his earthquake to register as ripples in the mercury.
0:16:52 > 0:16:54Rather like that.
0:16:54 > 0:16:57Now, today we're going to be standing a safe distance away
0:16:57 > 0:17:01from the blast, and away from the mercury, so we've set up this
0:17:01 > 0:17:05video camera here in the hope that it will record any reaction
0:17:05 > 0:17:07that we get from our explosion.
0:17:07 > 0:17:11Whether or not it will work, well, that remains to be seen.
0:17:13 > 0:17:17That's the other thing. I'm really worried our explosion
0:17:17 > 0:17:23won't be big enough to register the shockwaves in the mercury 100 metres away, so I've called in some help.
0:17:23 > 0:17:27Scientists from the Dublin Institute who will measure the explosion using
0:17:27 > 0:17:31a sensitive 21st century seismometer.
0:17:31 > 0:17:38Cheating? I don't think so, because this experiment by Robert Mallet 160 years ago was the mother of the idea
0:17:38 > 0:17:41that led to the invention of seismometers.
0:17:41 > 0:17:46But does seismologist, Tom Blake, think our experiment using mercury will work?
0:17:46 > 0:17:49Yes, I'm very confident that it will.
0:17:49 > 0:17:52We have the ghost of Robert Mallet behind us I'm sure.
0:17:57 > 0:17:59Yes, we're ready to go, yes.
0:18:01 > 0:18:04OK, well, Dave when you're ready, do the honours.
0:18:07 > 0:18:09BOOMING
0:18:09 > 0:18:13- Oh, yes. Look it's very good.- You could really see it. Oh, fantastic!
0:18:13 > 0:18:15Excellent. very, very good.
0:18:15 > 0:18:17You missed the blast, though, that was fantastic.
0:18:21 > 0:18:24- So, this is the modern technology working.- Exactly.
0:18:24 > 0:18:26- What do you think about the mercury? - Let's go and check it.
0:18:26 > 0:18:29Let's see what the camera shows us.
0:18:29 > 0:18:31Just go back a bit.
0:18:34 > 0:18:37- Oh, yes. Wow.- That's the one.
0:18:37 > 0:18:39That's really impressive, yes.
0:18:39 > 0:18:42I want to see it again.
0:18:44 > 0:18:47- That's very good.- The concentric rings coming in and out.
0:18:47 > 0:18:48Exactly, yes. Very, very good.
0:18:48 > 0:18:53And from that, Mallet basically kick-started seismology.
0:18:53 > 0:18:55Yes, he did his first measurements purely and simply
0:18:55 > 0:18:59with a simple mercury dish like this and a chronometer.
0:19:00 > 0:19:05After his first experiment here on Killiney Beach, Robert Mallet attempted to
0:19:05 > 0:19:09map the distribution and intensity of the world's known earthquakes.
0:19:09 > 0:19:12He was within a whisker of a discovery which would take
0:19:12 > 0:19:17over a century to fully realise, that the earth's crust is made up
0:19:17 > 0:19:22of constantly shifting plates, and that it's their movement that causes earthquakes.
0:19:22 > 0:19:27The germ of that understanding was formed in Ireland, on Killiney Beach.
0:19:27 > 0:19:30Subtitles by Red Bee Media Ltd
0:19:30 > 0:19:33E-mail subtitling@bbc.co.uk