On 12 December, 1901, three faint clicks tapping out the Morse code for the letter "s" were picked up by an aerial held aloft by a kite on the coast of Canada. 

The signals had been sent for the first time across the Atlantic from a makeshift wireless station on a cliff at Poldhu in Cornwall, England. 

The Italian inventor Guglielmo Marconi masterminded this visionary experiment, earning a place in history as the "father of wireless". 

This week's centenary of the first transatlantic radio signal will be marked by the opening of a museum dedicated to Marconi and his achievements. 

Dawn of radio 

A few days short of the 100th anniversary, Carolyn Rule, chair of the Poldhu Amateur Radio Club, sits in front of hi-tech radio equipment looking out at the field from which the first transatlantic radio signal was sent. 
 

"It's quite an emotional thing to be sitting here looking out on to the wireless field," she says. "You can see the ruins over there just ahead of us which is the actual remains of the original wireless building that Marconi would have used." 

On 11 December, 1901, the first attempt at transmission from Poldhu took place - and failed. 

Click here to view the original article and to listen to Sir Ambrose Fleming - whose equipment was used in the Atlantic experiment - talking about the early days of wireless. 

Poldhu pilgrimage 

A weak signal was received in Canada but the wind was so strong that the balloon holding the aerial aloft was swept away. 

"The chief question," Marconi said at the time, "was whether wireless waves would be stopped by the curvature of the Earth. All along, I had been convinced that this was not so. The first and final answer came at 12:30 when I heard...dot...dot..dot." 
 

Each year, hundreds of radio enthusiasts from all over the world make a pilgrimage to Poldhu to pay homage to Marconi. 

Historic remains 

The ruins of the original building built by Marconi to send the signal across the ocean are still visible in the cliff-top field at the edge of the Lizard Peninsula. 

Beyond that, over a dry-stone wall, lies a memorial to Marconi and then the ocean stretching more than 2,700 kilometres (1,700 miles) to Canada. 

"It's hard to believe that these ruins started it all - radio, TV and internet," says Debbie Peers, of the National Trust, which owns the land. 

Due respect 

To celebrate the centenary, the National Trust has constructed a new building on the site with the help of Marconi plc and a local grant. 

The building houses radio equipment, an exhibit on Marconi and computers that link with Marconi plc's archive collection on their founder. 

The 100th anniversary will also be commemorated by a re-enactment of Marconi's historic transmission. 

Signals from Mars 

Members of the Poldhu Amateur Radio Club will send the "s" signal across the water to radio enthusiasts in Newfoundland, just as Marconi did all those years ago. 

Carolyn Rule admits that it is a little easier nowadays. "We can cheat a little with e-mails and mobile phones," she says. 

Marconi proved what many respected scientists doubted - that a signal could be picked up thousands of kilometres away in Canada. 

At the time it was thought that wireless communication over long distances would never be possible because electromagnetic waves, which travel in straight lines, would be radiated into space or absorbed by the curve of the Earth. 
 

But he could scarcely have imagined that one day it would be possible to stand on the same Cornish cliff-top and send a fax, e-mail or text message anywhere in the world; or that giant telescopes would be tuning in to radio waves sent from deep space. 

Marconi was often asked whether he had ever heard signals from Mars. He always replied: "I am concerned enough at present with business upon Earth."