05 dezembro 2005

Wiring up the 'Victorian internet'

















(Gutta percha provided the key to good cable insulation)

The world's first global communications system for exchanging text messages was not the internet nor the mobile phone.

It was the great engineering project undertaken 150 years ago to put wires across the globe.

In an editorial on 20 April, 1857, the New York Herald commented: "The laying of the telegraph around the world is the great work of the age."

For the first time in history, the telegraph made rapid communication possible between Europe and America, and between Britain and her distant colonies such as Australia.

"It's worth trying to imagine how fantastic it would have been when that cable was finally completed and instead of taking 45 days for a message to get through from Britain to Australia, it took less than 24 hours," says Mary Godwin, director of the Porthcurno Telegraph Museum in Cornwall.

The story of how they put a "A Wire Around The World" and Porthcurno's central role is told in a BBC Radio 4 documentary.

Simple code

The idea of electrical communication seems to have begun as long ago as 1746, when about 200 monks at monastery in Paris arranged themselves in a line over a mile long, each holding ends of 25ft iron wires.

The abbot, also a scientist, discharged a Leiden jar (a primitive electrical battery) into the wire, giving all the monks a simultaneous electrical shock.

"This all sounds very silly, but is in fact extremely important because, firstly, they all said 'ow' which showed that you were sending a signal right along the line; and, secondly, they all said 'ow' at the same time, and that meant that you were sending the signal very quickly," explains Tom Standage, author of the Victorian Internet and technology editor at the Economist.

Given a more humane detection system, this could be a way of signalling over long distances.

With wars in Europe and colonies beyond, such a signalling system was urgently needed.

All sorts of electrical possibilities were proposed, some of them quite ridiculous. Two Englishmen, William Cooke and Charles Wheatstone came up with a system in which dials were made to point at different letters, but that involved five wires and would have been expensive to construct.

Much simpler was that of an American, Samuel Morse, whose system only required a single wire to send a code of dots and dashes.

At first, it was imagined that only a few highly skilled encoders would be able to use it but it soon became clear that many people could become proficient in Morse code.

A system of lines strung on telegraph poles began to spread in Europe and America.

Strange seaweed

The next problem was to cross the sea. Britain, as an island with an empire, led the way.

Any such cable had to be insulated and the first breakthrough came with the discovery that a rubber-like latex from a tree on the Malay peninsula could do the trick.

It was called gutta percha. The first attempt at a cross channel cable came in 1850. With thin wire and thick installation, it floated and had to be weighed down with lead pipe.

It never worked well as the effect of water on its electrical properties was not understood, and it is reputed that a French fishermen hooked out a section and took it home as a strange new form of seaweed.

The first transatlantic cable fared little better. Neither Cyrus W Field, the entrepreneur behind the project, nor his chief engineer, Edward Whitehouse, knew much about electricity.

The cable was too big for a single boat so two had to start in the middle of the Atlantic, join their cables and sail in opposite directions.

Amazingly, they succeeded in 1858, and this enabled Queen Victoria to send a telegraph message to President Buchanan.

However, the 98-word message took more than 19 hours to send and a misguided attempt to increase the speed by increasing the voltage resulted in failure of the line a week later.

Communications hub

In spite of claims that the whole thing had been a hoax, funding was found to try again and Brunel's mighty ship the Great Eastern was adapted to carry enough cable to span the Atlantic.

On the first attempt, the cable snapped after 1,300 miles but the second succeeded and the ship went on to retrieve the first, broken cable and complete that, too.

Such was the demand that the new transatlantic telegraph did £1,000 pounds of business in the first day.

Many of the early cables came ashore on the soft sandy beach of Porthcurno in Cornwall, near Lands End.

The Falmouth, Gibraltar and Malta Cable Company moved there when they realised that anchors in Falmouth might catch on cables.

That company eventually became Cable and Wireless. At its height, Porthcurno was the busiest telegraph station in the world, with 14 submarine lines coming ashore.

One of them took the telegraph on from the Mediterranean through the Red Sea to Aden, across the Arabian Sea and the Indian subcontinent and via Singapore and the jungles of Java towards Australia.

A young Englishman, Charles Todd, and his wife Alice, came to set up South Australia's first astronomical observatory in 1855, but soon realised that what the country most needed was a rapid communications link.

Poor returns

By 1870, a submarine cable was heading towards Australia. It seemed likely that it would come ashore at the northern port of Darwin from where it might connect around the coast to Queensland and New South Wales.

South Australia realised it would miss out, and Charles Todd was determined that this should not happen and put in a courageous bid to run an overland telegraph line right across the heart of the Australian continent, a distance of 2,700 miles, through territory which had hardly even been explored.

It was an undertaking more ambitious than spanning an ocean. Flocks of sheep had to be driven with the 400 workers to provide food.

They needed horses and bullock carts and, for the parched interior, camels. In the north, tropical rains left the teams flooded.

In the centre, it seemed that they would die of thirst. One critical section in the red heart of Australia involved finding a route through the McDonnell mountain range and then finding water on the other side.

The water was not only essential for the construction team. There had to be telegraph repeater stations every few hundred miles to boost the signal and the staff obviously had to have a supply of water.

Just as one mapping team was about to give up and resort to drinking brackish water, some aboriginals took pity on them.

"My great grandfather's brother saw these people drinking water down near the Heathertree Gap and felt sorry for them, because that's salty water down there, and he brought them up here to drink the good water," Betty Pierce, a descendent of those aboriginals, told the BBC.

There, they built their telegraph station, and named it after Charles Todd's wife. Today, Alice Springs has become a major town, though the Aboriginals lost their tribal lands. "Our 'mob' lost everything," says Betty Pierce.

Small world

Altogether, 40,000 telegraph poles were used in the Australian overland wire. Some were cut from trees. Where there were no trees, or where termites ate the wood, steel poles were imported.

On Thursday, August 22, 1872, the overland line was completed and the first messages could be sent across the continent; and within a few months, Australia was at last in direct contact with England via the submarine cable, too. The line remained in service to bring news of the Japanese attack on Darwin in 1942.

It could cost several pounds to send a message and it might take several hours for it to reach its destination on the other side of the globe, but the world would never be same again.

Governments could be in touch with their colonies. Traders could send cargoes based on demand and the latest prices. Newspapers could publish news that had just happened and was not many months old.

And individuals could, for the first time, exchange almost instant messages with their friends and family on different continents.

The information age began not in the late 20th Century but the mid-19th.

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