THOUSANDS of rabbits could be saved from distressing experiments if dead
chickens were used in their place, a conference in Utrecht was told last
week.

Rabbits are widely used to establish whether chemicals, such as those used in
cosmetics, are hazardous to humans. In the Draize test, prescribed by the
European Commission, chemicals are dripped into rabbits’ eyes. The redness of
their eyelids and opacity of their corneas are then taken as a measure of the
damage the chemicals can cause. But Menk Prinsen of the Dutch research
organisation TNO in Zeist says that equally accurate results can be obtained
using the eyes of butchered chickens from slaughterhouses.

Prinsen says he can measure the potency of a chemical from its effect on the
thickness of a chicken’s cornea. The cornea remains active for several hours
after death, so the results are as accurate as those from the eyes of living
animals, he says.

An irritating substance will leave holes in the thin surface membrane of the
cornea. Water applied to the surface can then reach the spongy stroma inside the
cornea, causing it to swell. Intact, a chicken’s cornea is slightly thicker than
half a millimetre; when damaged, it can swell by up to 60 per cent.

“His method has great potential,” says Michael Balls, head of the European
Centre for Validation of Alternative Methods in Ispra, Italy. “But there’s a
great deal of difficulty with replacing the rabbit eye test.”

Britain’s Home Office and the European Commission tested Prinsen’s method two
years ago, along with other alternatives. These included tests with cows’ eyes
and blood vessels from chicken embryos. But none could reliably reproduce the
results of the rabbit eye test. The reason, says Balls, is that “the data from
rabbit tests themselves are so variable they can’t be reproduced”.

Prinsen argues that this is because the redness, swelling and opacity of
rabbits’ eyes are estimated subjectively, and what one researcher calls “light”
redness, another calls “heavy”. “Since no test can duplicate this, European
regulators and industry stick to the old ways.”

Prinsen thinks his test, or something similar, could at least be used to
separate out the totally innocent or very dangerous chemicals from more
borderline cases. This would cut the number of live rabbits used in tests.

Balls understands Prinsen’s frustration: “There’s conservatism with the
regulators as well as industry. But there’s willingness in both camps too.” The
European Commission plans to ban the Draize test in the cosmetics industry from
1998 if there is an alternative available that satisfies everyone.

AN underwater device that extracts power from the ocean swell has proved
itself in a small-scale prototype, and the Dutch company that devised it now
wants to go ahead with full-scale tests. The Archimedes Wave Swing generator
takes advantage of changes in water pressure caused by long waves rolling
overhead.

Most wave energy generators stand or float on the surface of the water, where
they take their energy from choppy waves. The available energy varies
considerably with the weather, making surface generators an unreliable source of
power. They are also easily damaged during storms.

The Archimedes Wave Swing device from Teamwork Technology of Purmerend, near
Amsterdam, relies instead on huge swell waves in the oceans. Coasts around the
North Sea or Irish Sea would not be suitable because these bodies of water are
simply not large enough. Some sections of Atlantic or Pacific coastline would be
ideal. Swell is more consistent and less destructive than choppier waves.

The device consists of two or more mushroom-shaped floaters 15 metres below
the surface. Each one is partly filled with air. The air chambers of the
mushrooms are connected together by pipes, while the base of each mushroom is
open, so that water can flow in and out freely.

When a wave peak passes over one mushroom, the water pressure increases and
water flows into the chamber from the bottom. Air leaves via the pipes. The
mushroom’s buoyancy will decrease and it will tend to sink and lose more
air.

If the distance between the two units has been chosen well, the neighbouring
mushroom will be experiencing the reverse process as a wave trough passes
overhead. Decreased pressure will suck in surplus air from its colleague and the
mushroom will rise.

As the waves move overhead they make the mushrooms rise and sink in turn and
this movement can be used to drive a generator.

Ocean swell varies somewhat in height, direction and wavelength, but not too
much. According to Teamwork’s founder, Fred Gardner, it should be possible to
optimise a system for a particular location and have it work under all
conditions.

A 1:20 scale model was tested successfully this summer by the Dutch energy
research centre ECN. Bauke Vriesema, an ECN researcher, says: “It’s a completely
new concept. One attractive thing is that it sits under the surface where it’s
more or less protected. But a full-scale prototype must be the final proof.”

Teamwork is now looking for money to build an 8-megawatt prototype off the
coast of Portugal.

The company has collected 2.3 million guilders (ÂŁ890 000) of the 3.3
million guilders it needs to build a full-size prototype. Among the contributors
are the Dutch Ministry of Economic Affairs, offshore company Hydraudyne
Pneumatiek and British and Portuguese firms.

According to Teamwork’s calculations, the world has 20 000 kilometres of
suitable ocean coastline, and each kilometre could generate 48 megawatts.

ULTRA-LIGHT zoom lenses, space telescopes that can change focus from Earth,
and bar code scanners that can read labels from any distance are all among the
developments promised by a microchip device developed at Delft University of
Technology in the Netherlands.

Researchers at the Delft Institute of Microelectronics and Submicron
Technology (DIMES) have come up with a chip carrying a single mirror that can
change shape almost instantaneously. The mirror is formed from a thin silicon
nitride film a couple of millimetres square and 0.7 micrometres
thick—one-hundredth the thickness of a human hair. This is coated with a
reflective layer of aluminium and framed in silicon, like a painting.

The framed mirror is mounted on a microchip that carries one or more
electrodes. A charge applied to a single electrode pulls the reflective film
down into a paraboloid—the shape of a miniature satellite dish. The focal
length of the mirror can be changed simply by changing the voltage on the
electrode.

“It means you can zoom without heavy lenses and moving parts,” says Simon
Middelhoek, the project leader. This can be useful for cameras, and for
equipment such as bar code scanners. These normally have a mirror with a fixed
focal length, which means that bar codes have to be a fixed distance from the
scanner to be read. The adjustable mirror could make life easier in warehouses
and shops.

“It’s a promising invention,” says Gert Verkade, an expert in optics with
Philips in Eindhoven. “The kind of adaptive optics they’ve made is unique.”

According to Middelhoek, the main appeal lies in the mirror’s ability to
react rapidly, and this could make it useful in ground-based telescopes. With
multiple electrodes the mirror can be deformed fast enough to follow the image
of a star as atmospheric turbulence makes it appear to wiggle in the sky. The
complex electromechanical systems that now do this cost ÂŁ100 000 or more.
“Our device is going to be much cheaper, thanks to microchip technology,” says
Gleb Vdovin, a Russian researcher working in Delft on the mirror chip. This is
going to make adaptive optics affordable, even for amateur astronomers.”

Middelhoek says astronomers might one day be able to change the optics in a
space telescope by transmitting new software, instead of sending up astronauts
to install new optics by hand.

The Delft group sees projection television as another application. By
mounting the nitride film on a rigid grid, they hope to form an array of
independently controllable mirrors, each one controlling the light that projects
a single pixel onto a screen. Together with the universities of Neuchatel in
Switzerland and Edinburgh in Scotland they are now working on a chip 16 pixels
square.

A SAVANNA plant with a phenomenal ability to endure drought owes its tenacity
to a glass-like substance that preserves its cells until the rains return. This
discovery, by a Dutch biophysicist and his students, could one day help
biotechnologists to develop crop varieties that are less vulnerable to
drought.

Like other plants, Craterostigma plantagineum, a native of southern
Africa, shrivels up when water is scarce. But unlike most, it can revive again.
Henk van As’s team from the Wageningen Agricultural University in the
Netherlands think they know why.

Dry conditions spell death for most living tissues because membranes inside
cells stick together when the moisture in between them disappears. Even if water
returns to the cell, the membranes cannot be separated without becoming
irreparably damaged.

ĐÓ°ÉÔ­´´s in the US suggested some time ago that some living things can
survive extreme desiccation by using sugars to rise from the dead (see “A
sweeter way to fresher food”, New ĐÓ°ÉÔ­´´, 15 May 1993, p 24).
Instead of forming crystals, sugar solution can dry to form a glassy substance.
Glass is a very slow flowing fluid, which can replace water in a cell’s
structure, so that the cells shrink less than they would otherwise.

ĐÓ°ÉÔ­´´s knew that many seeds form glass-like tissue which enables them to
survive for months in a dry form. Until now, however, no one had seen growing
plants exploit the same process.

It turns out that Craterostigma uses its stores of sucrose to
“vitrify” the fluid around its chloroplasts, the structures within cells where
photosynthesis occurs. “We suspected that Craterostigma played this
trick because we knew it makes huge amounts of sucrose when it is drying out,”
says van As.

The researchers used a technique called differential scanning calorimetry,
which measures the response of the sample to a steady increase in temperature.
By measuring the heat needed for a given temperature change in a sample of
dried-out Craterostigma leaf, they found that at a certain point the
temperature of the sample did not rise even though they were still adding heat.
They inferred that there had been a phase change in the sample, and the only
possibility at the temperatures used was a change from liquid to glass.

If the researchers can find out what makes the plant switch on its vitrifying
process, it may be possible to transfer the genes responsible to crop species
that are vulnerable to drought.

Normally, a beating heart jumps around too violently for a surgeon to work on with precision. So in conventional bypass surgery, the patient’s heart is temporarily “switched off” by filling it with a cold, potassium-rich liquid. A machine then takes over to keep the blood circulating.

This process can cause two main problems: the heart is deprived of oxygen during the operation, and the foreign surfaces over which the blood passes inside the heart-lung machine can trigger an inflammatory immune response in the patient. On average, patients have to stay in hospital for seven days to recover.

A team led by Cornelius Borst at the University of Utrecht has come up with a system that should solve both problems. Instead of stopping the heart, their new Octopus Method immobilises the section undergoing surgery by holding it in place with two miniature suction cups that are rigidly attached to the operating table. The suckers are placed on each side of a coronary artery near the spot where the bypass is needed, limiting the movement of the tissue to within a millimetre.

So far, the Octopus Method has been tried on 23 patients. On average, they left hospital after only 4 days and some went back to work after three weeks. As well as being better for the patients, this translates into huge cost savings. For example, use of a heart-lung machine costs ÂŁ600 and a day in a Dutch hospital costs ÂŁ400.

Almost 600 000 bypass operations are performed every year worldwide. For the simplest of these, the Octopus Method can be carried out through an incision as small as 10 centimetres. Where the job is more complex, surgeons using the new technique will still have to saw open the patient’s sternum, as they do for a conventional bypass. The Octopus Method will not be suitable for the most complicated bypasses. “We are moving toward an individual tailoring of treatment,” says Erik Jansen, a cardiac surgeon in Utrecht who has been using the new method.

Other surgeons remain cautious. Bas Mochtar, a cardiac surgeon at the Rotterdam University’s Dijkzigt Hospital, wants to see whether the new procedure can match the success of angioplasty, in which a balloon is inflated inside the artery to clear any blockage. “The quality of their work must match that of the usual method,” he says. “If it does, they win.”

WHEN oil is used to make plastics, it may merely be reverting to its chemical
origins. ĐÓ°ÉÔ­´´s at the Netherlands Institute of Sea Research on the North
Sea island of Texel say that compounds called alkanes, which make up a large
proportion of crude oil, originate from natural plastics produced by marine
algae.

Alkanes are simple chains of carbon saturated with atoms of hydrogen. The
smallest alkanes are gases such as propane and butane, but heavier members of
the family are liquid and constitute about 80 per cent of the mixture of
hydrocarbons found in crude oil.

Geochemists believe that the alkanes in oil are formed in marine sediments
when larger organic molecules are broken down during millions of years spent
under pressure and at temperatures of around 100 °C. Some researchers have
argued that the source materials are carbohydrates and proteins from dead marine
organisms. But these substances are quickly digested by bacteria, and are
therefore not very likely to end up in sediments on the seabed.

The Dutch team began to think again about the formation of alkanes after the
discovery, in the late 1980s, that many freshwater algae produce
polyethers—natural plastics in which long chains of carbon atoms are
hooked together by atoms of oxygen, forming a firm network that cannot easily be
degraded.

Polyethers can accumulate on the bottom of lakes, and the researchers
wondered if the same might happen at sea. When they analysed seven species of
algae found in marine plankton, four turned out to contain polyethers. “We think
it is located in the cell walls,” says team member Jaap Sinninghe
śŮ˛šłž˛őłŮĂŠ.

To simulate what happens in marine sediments over millions of years, the
Dutch researchers heated the algal biopolymer for 10 seconds at 600 °C. This
yielded many alkanes with a chain length of about 30 carbons, similar to those
in oil (Geochimica et Cosmochimica Acta, vol 60, p 1275). Treating raw
marine sediments in the same way produces a similar mixture of alkanes.

“People have been wondering all along how oil originates,” says Jan Smit, a
geologist and palaeontologist at the Free University of Amsterdam. “Algae are
the main source of biomass in the oceans, so the connection is a very reasonable
´Ç˛Ôąđ.”

Through no choice of their own, the English explorer Hugh Willoughby and his crew of 70 were the first non-native people to attempt to survive winter in the Arctic. In 1553 the two ships he captained became trapped when the Varzino River in the Kola Peninsula of Russian Lapland froze. Without proper clothing, shelter or medical supplies, they all died. Some later expeditions fared better, though they were no better equipped. Why should one succeed but another fail? Perhaps archaeological remains and the journals left behind by the explorers would provide some clues.

There were several expeditions in the 16th and 17th centuries. We recently visited the site of the first successful Arctic Ocean wintering on record. In August 1596, a ship from an expedition seeking a polar passage to the Far East lodged in ice off the northeastern coast of Novaya Zemlya, an island north of Russia. The expedition was lead by a Dutch sailor, Willem Barents, who had expected to find open sea around the North Pole. He reasoned that with the summer sun shining 24 hours a day his route would be ice-free. There was disagreement, and the second expedition ship had taken a different route. Barents and the crew spent winter aboard ship and on land. Twelve of the 17 men survived this and the hazardous journey home.

In 1630 eight Englishmen, put ashore for a deer-hunting trip, were accidentally left behind at Bellsund in the west of Spitsbergen, an island north of Scandinavia. Against all odds, they too survived.

Three years later, 14 Dutch whalers endured mixed fortunes. They had volunteered to stay – seven at the whaling settlement of Smeerenburg, in the far northwest of Spitsbergen, and the other seven at Jan Mayen, a tiny island north of Iceland and east of Greenland. Their aim was to defend the settlement against Spanish Basque looters – the first non-Arctic whalers – and to get a head start on their competitors when the whaling season started the following summer. The Spitsbergen team survived; those on Jan Mayen did not. The following year another team of seven Dutch whalers tried to overwinter on Spitsbergen. They all perished. There were no more volunteers for many years.

Looking at superficial evidence from these expeditions there was no correlation between preparation for the conditions and survival. Furthermore, and quite paradoxically, the northernmost winterings were actually more successful. Many members of the wintering teams kept journals which, together with archaeological remains, made it possible to compare the circumstances they faced. Unfortunately, no record has been found from Willoughby’s expedition, so it could not be included in the investigations.

In the summers between 1614 and 1660, Smeerenburg was a thriving settlement, with around 200 men processing blubber in seven whaling stations. A decade ago, a team of archaeologists led by one of the authors (Louwrens Hacquebord) returned to the site, where they unearthed the remains of houses, whaling equipment, tools, clothing, and 50 graves, including those of the seven ill-fated winterers.

Picnics at the North Pole

Our visit last summer to the place where Barents’ group spent their polar winter was, as far as we know, the first Western scientific expedition to Novaya Zemlya. But we were certainly not the first people to visit the site. What surprised us were the many signs of unauthorised visits – holes in the ground, marks from helicopter landings, and even a picnic site on the nearby beach, with benches, a primitive furnace and lots of discarded tins. Four days after we left, 90 tourists from the US, Japan, Britain and South America came ashore to have a look. Apparently, an American company organises cruises from Murmansk by ice-breaker, offering a barbecue at the geographic North Pole, followed by a visit to Barents’ wintering place.

In an otherwise barren landscape, the surface of the site was strangely green as a result of phosphates from human waste. Close examination of the ground revealed many small remains – metal nails, pieces of leather, cloth, ceramic and animal bones. Some of the wooden and metal rubbish was probably 400 years old, some clearly was not. Little remained of the house, whether because of tourists, polar bears or weathering. The Barents expedition journal tells of their abortive attempt to melt the permafrost with fires to make a better foundation. Four wooden foundation beams, one very badly decayed, placed on flat stones on the ground, are now all that remains. Measuring 7.8 by 5.5 metres, the hut would have provided about 3 square metres per person – not much if bad weather forced confinement for any length of time.

The weather was another surprise. We had expected milder weather than Barents experienced – in the ‘Little Ice Age’, which lasted from 1450 to 1850, mean temperatures were between 1 and 2 °C colder than nowadays – but the difference in conditions was far greater than we had anticipated. Barents’ ship was surrounded and nearly crushed by ice in late August 1596. But we were there in the second half of August 1992, and saw only one lone iceberg drifting by at a great distance. Nor was there much snow or frost. Yet Gerrit de Veer, who kept a diary throughout the winter of 1596/7, mentions heavy snow as early as 9 August, and says that in September the nails froze to their lips while they were building the house.

The study yielded few facts and figures about the weather that various teams had experienced. There were, however, plenty of descriptions. Most entries in the Barents expedition journal start with a meteorological report, describing the weather as ‘bad’, ‘unbelievably cold’, with ‘heavy snow’ or a ‘terrible storm’. The only accurate information is about wind direction – they had compasses. The prevailing wind in 1596/7 came from the northeast. Today it is from the southeast. Barents’ group measured the cold by the thickness of the ice inside the house walls – it reached a maximum of 5 centimetres. The mean temperature in January is estimated to have been -25 °C.

Burnt socks and frozen toes

Freezing conditions were the major hazard for all the teams. It was so cold at Smeerenburg that barrels of water that had been placed right beside the fire froze. At Novaya Zemlya, De Veer recorded that the men’s socks would burn before their feet could feel the heat of the fire. None of the wintering sites had trees, so driftwood, coal, turf and any spare wood were used for fuel. Flammable materials were always in short supply, so the men had to rely heavily on their inadequate clothing. On Novaya Zemlya and at Smeerenburg they managed to catch Arctic foxes – the Dutch used the fur to make hats, and converted their own felt hats into inner soles or shoes to replace their frozen leather ones. Even so, many men suffered frostbite in toes and fingers, and there were some amputations.

On Novaya Zemlya they broke traders’ rules and used cloth from the merchandise on board ship to make extra clothing and blankets. To stay warm in bed, the winterers at Bellsund slept in pairs. Barents’ men took heated stones or cannonballs to bed. Surprisingly, the 17th-century winterers did not use polar bear skins to make clothes, as later polar travellers did. Possibly they found the furs too rough, or difficult to tailor.

Food was the second most pressing problem – particularly vitamins. At that time scurvy, caused by a deficiency of vitamin C, was common in Europe. Whalers going to sea in April would start off with a deficiency, which would worsen because their diet contained only about 10 per cent of the required daily intake of vitamin C. Symptoms included painful joints, loose teeth, swollen, bleeding gums, and bleeding both under the skin and in the bowels.

Bloodstains on the bones at the Smeerenburg excavations show that the group that perished suffered bleeding in the joints, and between the bones and the fibrous membrane covering them. Some of the bones also had large longitudinal cracks, caused by poor-quality connective tissue within them – another symptom of vitamin C deficiency. Exercise was thought to be good, if painful therapy for scurvy. In fact it would have done nothing more than keep the men warm. Without a vitamin C supply, an excruciating death is inevitable.

But the first winterers at Smeerenburg were lucky. They collected a large amount of Cochlearia officinalis – known as ‘scurvy grass’ because it is rich in vitamin C – and simply scattered it on the floor of a vacant building to be eaten later. By chance, this freeze-dried it, conserving the vitamin C, which is notoriously difficult to store. The whalers on Jan Mayen and those who stayed at Smeerenburg the following year quickly ran out of fresh scurvy grass, a factor that contributed to their deaths. But the Englishmen at Bell Sound and the Dutch sailors on Novaya Zemlya had no scurvy grass at all. So how did they escape the disease? The truth is they didn’t. Barents’ group had severe scurvy when they left Novaya Zemlya in the summer of 1597. By then they had been away from home for 13 months and should have died months earlier without vitamin C. But they survived because they were successful hunters. Humans are among the very few mammals that cannot make their own vitamin C, so most fresh animal meat contains traces of it – just enough to postpone the worst effects of scurvy for quite some time. During the polar night of 1596/7, Barents’ group caught 26 foxes in home-made traps. At Bellsund, where the marooned Englishmen had originally come to hunt, they dined on 3 walruses, 11 polar bears, 19 reindeer, 50 foxes and 60 ivory gulls. The unsuccessful winterers caught very few animals.

So, those who died had no luck in collecting or storing scurvy grass, and were apparently bad at building traps or aiming a musket. Possibly their physical condition was too poor at the start to do anything well. For the Jan Mayen group another possibility exists: there were no foxes to catch, and the bear meat they ate was so badly cooked that they contracted trichinosis, a parasitic infection of muscle tissue which, like scurvy, makes movement difficult. Their first mention of extreme fatigue comes shortly after the first bear was eaten, and long before they mention scurvy.

Although hardly mentioned in the journals, mental problems were surely inevitable. Continual confinement, lack of daylight for months on end, hunger, homesickness and the apparent hopelessness of the situation would all have taken their toll. In the Bellsund journal, they complain of hallucinations. And during the first Smeerenburg wintering, one man thought he was possessed by the devil. That group also had collective hallucinations – several times they believed they saw the devil’s fleet in the bays of Spitsbergen, come to rescue them. The devil’s presence was felt so keenly that they would lay the table for eight instead of seven, so that he could join them for dinner. They also wrote of their fear of unknown noises – caused perhaps by ice cracking, animals, or the weather – and phenomena such as the aurora borealis.

Activity was essential to stave off boredom and control depression and other mental disorders. Two strong leaders, Jacob van Heemskerck, captain of the stranded ship on the Barents expedition, and Jacob Segersz van der Brugge, head of the first Smeerenburg wintering, ensured their men were kept occupied. Both encouraged games, such as a form of curling, reconnaissance trips, and hunting parties. They organised indoor exercises when the weather was bad. Van der Brugge punished anyone who overslept by depriving him of his breakfast, brandy ration and tobacco. Both groups kept to a strict daily and weekly schedule, which included regular prayer and observance of the Sunday rest.

Pray for survival

In the Jan Mayen journal, boredom is mentioned as early as 18 November. The men exchanged their life histories – ‘we had no money to count’, comments the writer sardonically. There is no mention of other activities to prevent boredom. They did pray and read the Bible, but the Sunday rest is not referred to.

This brings us to a striking difference between the successful and unsuccessful winterings: those who survived took religion much more seriously. When confronted with psychological problems, the Bell Sound deer hunters redoubled their prayers. The more pious groups ensured that Sunday rest was observed and that there was celebration of Christian feast days. By contrast, the journals from Jan Mayen and the second winter at Smeerenburg – both unsuccessful attempts – make no mention of Christmas, even though other details are reported on that date.

Prayer and Sunday observance would have provided a structure to their stay, as well as a daily routine to help orientate the men during the Arctic night. Celebrations were something to look forward to; they gave a feeling of unity and the brief illusion of being at home. With faith came hope and confidence for the future. Perhaps this emphasis on religious observance was less a sign of innate piety than an intuitive psychological insight on the part of the more successful leaders.

Of all the winter expeditions looked at, Barents’ was probably the most difficult expedition. Unprepared for the Arctic conditions, and with no previous wintering experience, they had moved into unknown territory, drawing maps as they went. Even Spitsbergen was warmer than the east coast of Novaya Zemlya – the Gulf Stream does not extend that far – and in Barents’ time the prevailing wind, then northeasterly, came straight off the Arctic ice shelf. Unlike the other teams, who could use ready-made buildings, Barents and his men had to build their own house. And finally, after ten months with winter ended and everybody sick and exhausted, their ship remained stuck in the ice. They were forced to make their escape in two open boats, with very little protection against the elements. It took more than two months to reach the nearest European town of Kola, in Murmansk, more than 610 kilometres away. The marvel is that they lost only five men – two during the winter and three, including Barents, on the way back through what is now called the Barents Sea.

As for us? We were a bit annoyed that the helicopter that came to pick us up from Novaya Zemlya was over an hour late.

Herbert Blankesteijn is a physicist and science journalist who reports on science and technology for a daily children’s programme on Dutch TV.

Louwrens Hacquebord is an archaeologist and geographer who heads the Arctic Centre of the University of Groningen in the Netherlands. The authors are preparing a book in Dutch on their trip to Novaya Zemlya.

Most dairy farmers already use milking machines but they have to attach
the apparatus to the cow’s teats, and detach it when the milking is done.
The difficulty for a robot would be finding the teats. The company Prolion
demonstrated its milk robot system, or Miros, at an agricultural exhibition
in Amsterdam last week. It solved the problem using ultrasound.

The system can service up to five milking stalls. Cows wear transponders
around their necks to identify themselves. When a cow enters a free stall,
the gate closes behind her and a radio transmitter in the stall sends a
signal to the transponder which replies to identify the cow. A computer
checks when she was last milked.

If the cow has been milked too recently, she is let out of the stall.
If the cow is due for milking, some food is dispensed for her to chew on
while the robot gets on with looking for her udder.

The robot first locates the udder using two ultrasound beams, then it
finds each of the teats individually with a rotating beam. A robot arm then
attaches the milking system to the teats.

One ultrasound device covers all five stalls: it is mounted on a rail,
so it can move along to any stall where it is needed to guide another milking
system to another set of teats. Johannes Bottema, product manager of Prolion,
says the system is ‘cow-friendly’.

Prolion claims the system will not only save time, but it will also
increase production by 10 to 20 per cent because cows can be milked more
often.

American researchers at the Agricultural Experiment Station of the University
of Maryland have been working with another prototype robot milking machine
also made by a Dutch company, called Gascoigne-Melotte. They are taking
a different approach to finding the teats: they program into the system
the position of the teats on each individual cow.

‘The problem,’ says Walt Williams, who heads the research, ‘is that
teats don’t stay in the same place. Udder shape and teat location change
as the udder fills with milk.’ The researchers set about measuring locations
of cows’ teats every four hours at different stages of lactation. They are
now working on a computer model that will allow the robot to calculate the
location of a cow’s teats based on when she was last milked and her stage
of lactation.

Productivity is increased because with a robotic system because the
cows are ‘essentially free to milk themselves whenever they want’, according
to Mark Varner who is studying the cows’ behaviour.

‘Conventional wisdom used to be that cows would return to the milking
parlour because they knew they would be fed.’ But the researchers found
that the cows came into the stalls even when no food was offered. ‘They
may just like to be milked,’ says Varner.

Some cows did not want to leave the milker after they had finished being
milked. ‘We’re not sure what the best way is to get the cow out of the milking
stall,’ he says.

The trial, which began last week, aims to see whether rubbish production
can be brought down this way. The Dutch government is desperately searching
for ways to deal with the country’s waste disposal problem. Incinerators
have insufficient capacity and the country is running out of landfill space.

The system on trial in Hoofddorp simply counts the times each dustbin
is emptied into the dustcart. Residents who take part in the trial receive
a dustbin with a built-in radio transponder containing their address and
postcode. Each time the dustbin is emptied, equipment on board the dustcart
sends out a radio signal and the transponder answers by sending back its
information. A computer on the dustcart then records whose dustbin it is.

After six months, those who have had their bins emptied 13 times or
less, rather than the usual 26, will get the maximum rebate of 30 Dutch
guilders ( £7.50) off their municipal ‘cleaning tax’. In the municipality
of Haarlemmermeer, to which Hoofddorp belongs, this tax is 82.50 guilders
per household every half year. The more people have their dustbins emptied,
the less the rebate will be.

The trial itself is costing Haarlemmermeer 35 000 guilders. Eventually,
it is hoped, the system will pay for itself by bringing down the cost of
waste collection.

According to Inge Pastoor, a spokeswoman for Haarlemmermeer, 1350 dustbins
were put out on the street last week in the trial area instead of the usual
1530. The total waste weight was 22.5 tonnes instead of 25. It remains to
be seen whether people will really throw away less, or just squeeze more
rubbish into one dustbin.

Hans Haleber of Nedap, the company that produces the electronics for
the Hoofddorp bins, says electronic fraud is impossible. ‘This system is
much better protected than a credit card. In order to change the information
in the transponder to, say, your neighbour’s address, you need special equipment,
codes, and a secret password,’ he says.

In Zaanstad, just north of Amsterdam, a trial is being prepared in which
dustbins will not only be counted, but also weighed. This is expected to
be more effective in persuading people to reduce their waste.

The beauty of the system is that it uses special phone numbers which
are provided by many countries so that travellers abroad can get a direct,
free connection to an operator in their home country. This way they can
ask for services such as reversed charges in their own language.

As the lines are provided free, there seems to be some confusion in
the main Dutch telecommunications company, PTT, on whether the trick is
illegal. But British Telecom says that the technique would be considered
illegal in Britain.

Ever since telephone companies switched to electronic exchanges which
rely on aud ible tones, phone phreaks have been abusing the system using
electronic tone pads.

Phone phreaking became a problem for telephone companies in the US in
the 1970s until they devised a way to prevent it. Last year, British Telecom
had to carry out a crash programme of modifications to every public call
box in Britain after phone phreaks found a loophole in the system. Last
month, 10 students from the University of Kent admitted in court to making
ÂŁ400 000 worth of calls from six unmodified call boxes on the university
campus.

The Dutch group of phone phreaks give a detailed description of their
technique in a computer hackers’ magazine published in Amsterdam called
Hack-Tic. They say they found the necessary technical information in the
library of the PTT itself and any reasonably equipped technical library
should also have the information.

In principle, the trick is very simple. As with many regular international
calls, when the free international line is established the caller hears
certain audible tones on the line.

The tones, which are different from the tones a regular touch-tone phone
generates, are commands from one exchange to another to open or close a
line. The tones are defined by an international standard known as CCITT
5, or C₅ for short.

It is relatively simple to build a device, known as a blue box, to generate
the necessary tones. To obtain a line, the caller dials a free number for
an operator in another country. Before the operator even answers, the caller
sends a ‘clear forward’ tone (2400 hertz and 2600 hertz tones simultaneously)
into the telephone using the blue box. This tells the international call
transit centre abroad to terminate the connection.

Before the centre has time to inform the exchange in the caller’s home
country, the caller sends another tone, known as ‘seize’ (2400 hertz) announcing
a request for another call. Still using C₅ tones, the caller
can then dial any number anywhere, even back in his or her own country.
Meanwhile, the telephone exchange at home thinks there is a free conversation
going on with an overseas operator. Hack-Tic’s most recent issue gives a
complete list of the C₅ tones and the free numbers for foreign
operators.

Rop Gonggrijp, one of the phone phreaks, is unrepentant about abusing
the system. ‘I want to show that the international phone network is a magnificent
toy. I get kicks out of steering the system and getting all kinds of weird
łŚ´Ç˛Ô˛ÔąđłŚłŮžą´Ç˛Ô˛ő.’

The group published details of the trick to stop others making a profit
from it. ‘I want to hit those people who are trying to make money out of
this by selling audio tapes with particular tone sequences,’ says Gonggrijp.
Such tapes contain tones to get a free connection for a particular number,
such as a relative in Australia.

PTT’s director of technical affairs for the Amsterdam area, Bram Willemse,
says that in the Netherlands there is nothing illegal in it. ‘We can’t forbid
people from trying one or two things with their telephone. We are even happy
to be shown a bug in the system in this way.’ But PTT’s press officer Fred
Lenderink maintains that phreaking is against Dutch law. However, no attempt
has been made so far to sue either Hack-Tic or Gonggrijp.

British Telecom runs a free operator service for overseas travellers.
A representative of BT says that this form of telephone fraud has not yet
been reported on its lines. If it was, however, BT would work together with
the Dutch PTT to stop it happening.