Poldhu
Encyclopedia
Poldhu is a small area in south Cornwall
, England
, UK
, situated on the Lizard Peninsula
; it comprises Poldhu Point and Poldhu Cove. It lies on the coast west of Goonhilly Downs
, with Mullion
2 kilometres (1.2 mi) to the south and Porthleven
7 kilometres (4.3 mi) to the north. Poldhu means "black pool" in Cornish
.
The site is famous as the location of Poldhu Wireless Station, Guglielmo Marconi
's transmitter for the first transatlantic radio
message on December 12, 1901 to Marconi's temporary receiving station on Signal Hill
, St. John's, Newfoundland
.
The station's fifty acre (200,000 m²) plot was bought in 1900 and construction work ran from October 1900 to January 1901, to a design by John Ambrose Fleming
. The original 20 mast circular aerial was destroyed in a storm on September 17, 1901. For Marconi's experiments a temporary installation of two 200 foot (61 m) masts was used. The transmitter operated with a power of roughly 13 kW and a wavelength usually estimated at 170 meters. The original mast layout was not rebuilt, it was replaced with a four mast design, 215 feet (66 m) high and forming a 200 foot (61 m) square.
Marconi later used the site for his shortwave
experiments, with transmissions by Charles Samuel Franklin
to Marconi on the yacht Elettra in the Cape Verde Islands in 1923 and in Beirut
in 1924. The groundbreaking results of these experiments took the world by surprise and quickly resulted in his development of the Beam Wireless Service
for the British General Post Office. The service opened from the Bodmin Beam Station to Canada on 25 October, 1926, from the Tetney Beam Station to Australia on 8 April 1927, from the Bodmin Beam Station to South Africa on 5 July 1927, to India on 6 September 1927 and shortly afterwards to Argentina, Brazil and the United States.
The station continued to operate until 1933. The site was cleared in 1935 and six acres (24,000 m²) were gifted to the National Trust
in 1937 with the rest of the site added in 1960. The site has a stone monument pillar and a number of concrete foundations and earth structures also remain. In 2001 the Marconi Centre, a new museum/meeting building, was opened close to the site by the efforts of the Poldhu Amateur Radio Club, the National Trust and Marconi plc.
The more substantial building near the site, originally the Poldhu Hotel, built from 1899 to house the Marconi workers, is currently a care home.
Marconi also built a second, much smaller, experimental wireless station nearby at Housel Bay - The Lizard Wireless Station
.
Cornwall
Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, situated on the Lizard Peninsula
The Lizard
The Lizard is a peninsula in south Cornwall, England, United Kingdom. The most southerly point of the British mainland is near Lizard Point at ....
; it comprises Poldhu Point and Poldhu Cove. It lies on the coast west of Goonhilly Downs
Goonhilly Downs
Goonhilly Downs is a Site of Special Scientific Interest that forms a raised plateau in the central western area of the Lizard Peninsula in Cornwall, England, UK. Situated just south of Helston and the Naval Air Station at Culdrose, it is famous for its Goonhilly Satellite Earth Station, the...
, with Mullion
Mullion, Cornwall
Mullion is a civil parish and village in Cornwall, United Kingdom. It is situated on the Lizard Peninsula approximately five miles south of Helston....
2 kilometres (1.2 mi) to the south and Porthleven
Porthleven
Porthleven is a town, civil parish and fishing port in Cornwall, United Kingdom, near Helston. It is the most southerly port on the island of Great Britain and was originally developed as a harbour of refuge, when this part of the Cornish coastline was recognised as a black spot for wrecks in days...
7 kilometres (4.3 mi) to the north. Poldhu means "black pool" in Cornish
Cornish language
Cornish is a Brythonic Celtic language and a recognised minority language of the United Kingdom. Along with Welsh and Breton, it is directly descended from the ancient British language spoken throughout much of Britain before the English language came to dominate...
.
Marconi's Poldhu Wireless Station
Guglielmo Marconi
Guglielmo Marconi was an Italian inventor, known as the father of long distance radio transmission and for his development of Marconi's law and a radio telegraph system. Marconi is often credited as the inventor of radio, and indeed he shared the 1909 Nobel Prize in Physics with Karl Ferdinand...
's transmitter for the first transatlantic radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
message on December 12, 1901 to Marconi's temporary receiving station on Signal Hill
Signal Hill, Newfoundland and Labrador
Signal Hill is a hill which overlooks the city of St. John's, Newfoundland and Labrador, Canada.Due to its strategic placement overlooking the harbour, fortifications have been placed on the hill since the mid 17th century.-History:...
, St. John's, Newfoundland
St. John's, Newfoundland and Labrador
St. John's is the capital and largest city in Newfoundland and Labrador, and is the oldest English-founded city in North America. It is located on the eastern tip of the Avalon Peninsula on the island of Newfoundland. With a population of 192,326 as of July 1, 2010, the St...
.
The station's fifty acre (200,000 m²) plot was bought in 1900 and construction work ran from October 1900 to January 1901, to a design by John Ambrose Fleming
John Ambrose Fleming
Sir John Ambrose Fleming was an English electrical engineer and physicist. He is known for inventing the first thermionic valve or vacuum tube, the diode, then called the kenotron in 1904. He is also famous for the left hand rule...
. The original 20 mast circular aerial was destroyed in a storm on September 17, 1901. For Marconi's experiments a temporary installation of two 200 foot (61 m) masts was used. The transmitter operated with a power of roughly 13 kW and a wavelength usually estimated at 170 meters. The original mast layout was not rebuilt, it was replaced with a four mast design, 215 feet (66 m) high and forming a 200 foot (61 m) square.
Marconi later used the site for his shortwave
Shortwave
Shortwave radio refers to the upper MF and all of the HF portion of the radio spectrum, between 1,800–30,000 kHz. Shortwave radio received its name because the wavelengths in this band are shorter than 200 m which marked the original upper limit of the medium frequency band first used...
experiments, with transmissions by Charles Samuel Franklin
Charles Samuel Franklin
Charles Samuel Franklin , who published as C. S. Franklin, was a noted British radio pioneer.Franklin was born in London, the youngest of a family of 13, and educated at Finsbury Technical College in Finsbury, England, under Silvanus P. Thompson. After graduation in 1899 he joined the Marconi...
to Marconi on the yacht Elettra in the Cape Verde Islands in 1923 and in Beirut
Beirut
Beirut is the capital and largest city of Lebanon, with a population ranging from 1 million to more than 2 million . Located on a peninsula at the midpoint of Lebanon's Mediterranean coastline, it serves as the country's largest and main seaport, and also forms the Beirut Metropolitan...
in 1924. The groundbreaking results of these experiments took the world by surprise and quickly resulted in his development of the Beam Wireless Service
Imperial Wireless Chain
The Imperial Wireless Chain, also known as the Empire Wireless Chain, was a strategic international wireless telegraphy communications network, created to link the countries of the British Empire. Although the idea was conceived prior to World War I, Britain was the last of the world's Great Powers...
for the British General Post Office. The service opened from the Bodmin Beam Station to Canada on 25 October, 1926, from the Tetney Beam Station to Australia on 8 April 1927, from the Bodmin Beam Station to South Africa on 5 July 1927, to India on 6 September 1927 and shortly afterwards to Argentina, Brazil and the United States.
The station continued to operate until 1933. The site was cleared in 1935 and six acres (24,000 m²) were gifted to the National Trust
National Trust for Places of Historic Interest or Natural Beauty
The National Trust for Places of Historic Interest or Natural Beauty, usually known as the National Trust, is a conservation organisation in England, Wales and Northern Ireland...
in 1937 with the rest of the site added in 1960. The site has a stone monument pillar and a number of concrete foundations and earth structures also remain. In 2001 the Marconi Centre, a new museum/meeting building, was opened close to the site by the efforts of the Poldhu Amateur Radio Club, the National Trust and Marconi plc.
The more substantial building near the site, originally the Poldhu Hotel, built from 1899 to house the Marconi workers, is currently a care home.
Marconi also built a second, much smaller, experimental wireless station nearby at Housel Bay - The Lizard Wireless Station
The Lizard
The Lizard is a peninsula in south Cornwall, England, United Kingdom. The most southerly point of the British mainland is near Lizard Point at ....
.