Heliograph
Encyclopedia
A heliograph is a wireless solar telegraph that signals by flashes of sunlight
Sunlight
Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the Earth's atmosphere, and solar radiation is obvious as daylight when the Sun is above the horizon.When the direct solar radiation is not blocked...

 (generally using Morse code
Morse code
Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...

) reflected by a mirror
Mirror
A mirror is an object that reflects light or sound in a way that preserves much of its original quality prior to its contact with the mirror. Some mirrors also filter out some wavelengths, while preserving other wavelengths in the reflection...

. The flashes are produced by momentarily pivoting the mirror, or by interrupting the beam with a shutter. The heliograph was a simple but effective instrument for instantaneous optical communication
Optical communication
Optical communication is any form of telecommunication that uses light as the transmission medium.An optical communication system consists of a transmitter, which encodes a message into an optical signal, a channel, which carries the signal to its destination, and a receiver, which reproduces the...

 over long distances during the late 19th and early 20th century. Its main uses were military, survey and forest protection work. Heliographs were standard issue in the British and Australian armies until the 1960s, and were used by the Pakistani army as late as 1975.

Description

There were many heliograph types. Most heliographs were variants of the British army
British Army
The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...

 Mance Mark V version (Fig.1). It used a mirror with a small sighting hole in the middle. The sender looked through this hole to align the tip of a sighting rod with the target.
He then aligned the mirror so the small shadow that was the reflection of the sighting hole was on the tip of the sighting rod. This indicated that the sunbeam was pointing at the target. The flashes were produced by a keying mechanism that tilted the mirror up a few degrees at the push of a lever at the back of the instrument. If the sun was in front of the sender, its rays were reflected directly from this mirror to the receiving station. If the sun was behind the sender, the sighting rod was replaced by a second mirror, to capture the sunlight from the main mirror and reflect it to the receiving station. The U. S. Signal Corps
United States Army Signal Corps
The United States Army Signal Corps develops, tests, provides, and manages communications and information systems support for the command and control of combined arms forces. It was established in 1860, the brainchild of United States Army Major Albert J. Myer, and has had an important role from...

 heliograph mirror did not tilt. This type produced flashes by a shutter
Shutter (photography)
In photography, a shutter is a device that allows light to pass for a determined period of time, for the purpose of exposing photographic film or a light-sensitive electronic sensor to light to capture a permanent image of a scene...

 mounted on a second tripod (Fig 4).

The heliograph had some great advantages. It allowed long distance communication without a fixed infrastructure, though it could also be linked to make a fixed network extending for hundreds of miles, as in the fort-to-fort network used for the Geronimo
Geronimo
Geronimo was a prominent Native American leader of the Chiricahua Apache who fought against Mexico and the United States for their expansion into Apache tribal lands for several decades during the Apache Wars. Allegedly, "Geronimo" was the name given to him during a Mexican incident...

 campaign. It was very portable, did not require any power source, and was relatively secure since it was invisible to those not near the axis of operation. However, anyone in the beam with the correct knowledge could intercept signals without being detected. For the Boer war
Second Boer War
The Second Boer War was fought from 11 October 1899 until 31 May 1902 between the British Empire and the Afrikaans-speaking Dutch settlers of two independent Boer republics, the South African Republic and the Orange Free State...

, where both sides used heliographs, tubes were sometimes used to decrease the dispersion of the beam.

The distance that heliograph signals could be seen depended on the clarity of the sky and the size of the mirrors used. A clear line of sight was required, and since the Earth's surface is curved, the highest convenient points were used. For ordinary conditions, a flash could be seen 30 miles (48 km) with the naked eye, and much farther with a telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

. The maximum range was considered to be 10 miles for each inch of mirror diameter. Mirrors ranged from 1.5 inches to 12 inches or more. The record distance was established by a detachment of U.S. signal sergeants by the inter-operation of stations on Mount Ellen
Mount Ellen (Utah)
Mount Ellen is a mountain located in Garfield County, Utah. The high point of Mount Ellen's North Summit Ridge is the highest point in the Henry Mountains; it is also the highest point in Garfield County. It can be reached by a short hike from an unpaved road. These mountains were the last to be...

, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

, and Mount Uncompahgre
Uncompahgre Peak
Uncompahgre Peak is the sixth highest mountain peak in the U.S. state of Colorado and is the highest peak of the San Juan Mountains. It is located in the Uncompahgre Wilderness in the northern San Juans, in northern Hinsdale County approximately 7 miles west of the town of Lake City.Uncompahgre...

, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

, 183 miles (295 km) apart on September 17, 1894, with Signal Corps heliographs carrying mirrors only 8 inches square.

History

The German professor Carl Friedrich Gauss
Carl Friedrich Gauss
Johann Carl Friedrich Gauss was a German mathematician and scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics.Sometimes referred to as the Princeps mathematicorum...

, of Georg-August University of Göttingen
Georg-August University of Göttingen
The University of Göttingen , known informally as Georgia Augusta, is a university in the city of Göttingen, Germany.Founded in 1734 by King George II of Great Britain and the Elector of Hanover, it opened for classes in 1737. The University of Göttingen soon grew in size and popularity...

, described a first design for a predecessor of the heliograph (called heliotrope
Heliotrope (instrument)
The heliotrope is an instrument that uses a mirror to reflect sunlight over great distances to mark the positions of participants in a land survey. The heliotrope was invented by the German mathematician Carl Friedrich Gauss....

) during 1810. His device directed a controlled beam of sunlight to a distant station to be used as a marker for geodetic survey work.

Sir Henry Christopher Mance (1840–1926), of British Army Signal Corps, developed the first apparatus about 1869 while stationed at Karachi
Karachi
Karachi is the largest city, main seaport and the main financial centre of Pakistan, as well as the capital of the province of Sindh. The city has an estimated population of 13 to 15 million, while the total metropolitan area has a population of over 18 million...

, in the Bombay Presidency
Bombay Presidency
The Bombay Presidency was a province of British India. It was established in the 17th century as a trading post for the English East India Company, but later grew to encompass much of western and central India, as well as parts of post-partition Pakistan and the Arabian Peninsula.At its greatest...

 in British India. Mance was familiar with heliotropes by their use for the Great India Survey. The Mance Heliograph was operated easily by one man, and since it weighed about seven pounds, the operator could readily carry the device and its tripod. During the Jowaki Afridi expedition sent by the British-Indian government during 1877, the heliograph was first tested in war.
The simple and effective instrument that Mance invented was to be an important part of military communications for more than 60 years. The usefulness of heliographs was limited to daytimes with strong sunlight, but they were the most powerful type of visual signaling device known. During pre-radio times heliography was often the only means of communication that could span ranges of as much as 100 miles with a lightweight portable instrument.

In the United States military, by January 1880, Colonel Nelson A. Miles
Nelson A. Miles
Nelson Appleton Miles was a United States soldier who served in the American Civil War, Indian Wars, and the Spanish-American War.-Early life:Miles was born in Westminster, Massachusetts, on his family's farm...

 had established a line of heliographs connecting Fort Keogh and Fort Custer, Montana, a distance of 140 miles. Major W. J. Volkman of the US Army, demonstrated in Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

 and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

 the possibility of performing communication by heliograph over a range of 200 miles. The network of communication begun by General Miles during 1886, and continued by Lieutenant W. A. Glassford, was perfected during 1889 at ranges of 85, 88, 95, and 125 miles over a rugged and broken country, which was the stronghold of the Apache
Apache
Apache is the collective term for several culturally related groups of Native Americans in the United States originally from the Southwest United States. These indigenous peoples of North America speak a Southern Athabaskan language, which is related linguistically to the languages of Athabaskan...

 and other hostile Indian tribes.

By 1887, heliographs in use included not only the British Mance and Begbie heliographs, but also the American Grugan, Garner and Pursell heliographs. The Grugan and Pursell heliographs used shutters, and the others used movable mirrors operated by a finger key. The Mance, Grugam and Pursell heliographs used two tripods, and the others one. The signals could either be momentary flashes, or momentary obscurations. During 1889, the US Signal Service reviewed all of these devices, as well as the Finley Helio-Telegraph, and finding none completely suitable, developed the US Signal Service heliograph, a two-tripod, shutter-based machine of 13 7/8 lb. total weight, and ordered 100 for a total cost of $4,205.

The heyday of the heliograph was probably the Second Boer War
Second Boer War
The Second Boer War was fought from 11 October 1899 until 31 May 1902 between the British Empire and the Afrikaans-speaking Dutch settlers of two independent Boer republics, the South African Republic and the Orange Free State...

 in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

, where it was much used by both the British and the Boers. The terrain and climate, as well as the nature of the campaign, made heliography a logical choice. For night communications, the British
United Kingdom of Great Britain and Ireland
The United Kingdom of Great Britain and Ireland was the formal name of the United Kingdom during the period when what is now the Republic of Ireland formed a part of it....

 used some large Aldis lamps, brought inland on railroad cars, and equipped with leaf-type shutters for keying a beam of light into dots and dashes. During the early stages of the war, the British garrisons were besieged in Kimberley
Kimberley, Northern Cape
Kimberley is a city in South Africa, and the capital of the Northern Cape. It is located near the confluence of the Vaal and Orange Rivers. The town has considerable historical significance due its diamond mining past and siege during the Second Boer War...

, Ladysmith
Siege of Ladysmith
The Siege of Ladysmith was a protracted engagement in the Second Boer War, taking place between 30 October 1899 and 28 February 1900 at Ladysmith, Natal.-Background:...

, and Mafeking
Siege of Mafeking
The Siege of Mafeking was the most famous British action in the Second Boer War. It took place at the town of Mafeking in South Africa over a period of 217 days, from October 1899 to May 1900, and turned Robert Baden-Powell, who went on to found the Scouting Movement, into a national hero...

. With land telegraph lines cut, the only contact with the outside world was via light-beam communication, helio by day, and Aldis lamps at night.

During 1909, the use of heliography for forestry protection was introduced in the United States. By 1920 such use was widespread in the US and beginning in Canada, and the heliograph was regarded as "next to the telephone, the most useful communication device that is at present available for forest-protection services". D.P. Godwin of the US Forestry Service invented a very portable (4.5 lb) heliograph of the single-tripod, shutter plus mirror type for forestry use.

The Red Army
Red Army
The Workers' and Peasants' Red Army started out as the Soviet Union's revolutionary communist combat groups during the Russian Civil War of 1918-1922. It grew into the national army of the Soviet Union. By the 1930s the Red Army was among the largest armies in history.The "Red Army" name refers to...

 during the Russian Civil War made use of series of heliograph stations to disseminate intelligence efficiently about basmachi rebel movements in Turkestan
Turkestan
Turkestan, spelled also as Turkistan, literally means "Land of the Turks".The term Turkestan is of Persian origin and has never been in use to denote a single nation. It was first used by Persian geographers to describe the place of Turkish peoples...

 during 1926.

The heliograph remained standard equipment for military signaller
Signaller
In the armed forces, a signaller or signaleer is a specialist soldier or seaman or airman responsible for military communications. Signallers, aka Combat Signallers or signalmen or women, are commonly employed as radio or telephone operators, relaying messages for field commanders at the front line...

s in the Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

n and British armies
British Army
The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...

 until the 1960s, where it was considered a "low probability of intercept" type of communication. Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 had the last major army to have the heliograph as an issue item. By the time the mirror instruments were retired they were seldom used for signalling. As recently as the 1980s, heliographs were used by Afghan
Afghanistan
Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...

 forces during the Soviet invasion of Afghanistan. Signal mirrors are still included in survival kit
Survival kit
A survival kit is a package of basic tools and supplies prepared in advance as an aid to survival in an emergency. Military aircraft, lifeboats, and spacecraft are equipped with survival kits....

s for emergency signaling to search and rescue
Search and rescue
Search and rescue is the search for and provision of aid to people who are in distress or imminent danger.The general field of search and rescue includes many specialty sub-fields, mostly based upon terrain considerations...

 aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

.

Heliographs in fiction

  • Rudyard Kipling
    Rudyard Kipling
    Joseph Rudyard Kipling was an English poet, short-story writer, and novelist chiefly remembered for his celebration of British imperialism, tales and poems of British soldiers in India, and his tales for children. Kipling received the 1907 Nobel Prize for Literature...

    's humorous poem "A Code of Morals" describes a fictional interception of a heliograph signal in 19th century Afghanistan.
  • In the book The War of the Worlds
    The War of the Worlds
    The War of the Worlds is an 1898 science fiction novel written by H. G. Wells.The War of the Worlds may also refer to:- Radio broadcasts :* The War of the Worlds , the 1938 radio broadcast by Orson Welles...

    by H.G. Wells (1898), heliographs are used to convey information about the invading Martian
    Martian
    As an adjective, the term martian is used to describe anything pertaining to the planet Mars.However, a Martian is more usually a hypothetical or fictional native inhabitant of the planet Mars. Historically, life on Mars has often been hypothesized, although there is currently no solid evidence of...

    s.
  • The short story "The Attack on the Mountain" by Glendon Swarthout, in the Saturday Evening Post Magazine, July 4, 1959, described the use of the heliograph in the American West.
  • The 2004 Western novel The Sergeant's Lady by Miles Hood Swarthout is set against the background of the heliograph network used in the U.S. Army campaign against the Apache Indians
    Apache
    Apache is the collective term for several culturally related groups of Native Americans in the United States originally from the Southwest United States. These indigenous peoples of North America speak a Southern Athabaskan language, which is related linguistically to the languages of Athabaskan...

    .
  • In the 2010 science fiction novel "Terminal World" by Alastair Reynolds
    Alastair Reynolds
    Alastair Preston Reynolds is a British science fiction author. He specialises in dark hard science fiction and space opera. He spent his early years in Cornwall, moved back to Wales before going to Newcastle, where he read physics and astronomy. Afterwards, he earned a PhD from St Andrews, Scotland...

    , the faction of people known as 'Swarm' use heliographs as communication between airships.
  • In Robert Penn Warren's "All the King's Men", a heliograph serves as an important image and appears early—- on the second page of the novel.
  • In Agatha Christie's 1947 novel The Labours of Hercules
    The Labours of Hercules
    The Labours of Hercules is a short story collection written by Agatha Christie and first published in the US by Dodd, Mead and Company in 1947 and in the UK by Collins Crime Club in September of the same year...

    from the short story "The Erymanthian Boar" detective Hercule Poirot uses a heliograph to communicate from the top of Rochers Neiges where he is trapped to the police at the mountain's base.
  • In Larry Niven's Ringworld
    Ringworld
    Ringworld is a Hugo, Nebula, and Locus award-winning 1970 science fiction novel by Larry Niven, set in his Known Space universe and considered a classic of science fiction literature. It is followed by three sequels, and preceded by four prequels, and ties into numerous other books set in Known Space...

     series, revealed in The Ringworld Throne
    The Ringworld Throne
    The Ringworld Throne is a novel by Larry Niven, first published in 1996. It is the direct sequel to his previous work The Ringworld Engineers...

    , the Ghoul species use heliographs for their vast communication network across the Ringworld. The Spill Mountain People are the only species outside of the Ghouls to know of this means of communication until Louis Wu spoke to the protector Tunesmith.
  • In the role-playing game
    Role-playing game
    A role-playing game is a game in which players assume the roles of characters in a fictional setting. Players take responsibility for acting out these roles within a narrative, either through literal acting, or through a process of structured decision-making or character development...

     Space: 1889
    Space: 1889
    Space: 1889 is a role-playing game of Victorian-era space-faring,created by Frank Chadwick and originally published by Game Designers' Workshop from 1988 to 1991 and later reprinted by Heliograph, Inc...

    , the Great Powers communicate with their colonial possessions on the inner planets of the Solar System by means of "orbiting heliograph stations".
  • In the Tintin
    Tintin
    Tintin, Tin-Tin or Tin Tin may refer to:* The Adventures of Tintin , the series of classic comic books created by Belgian artist Hergé...

     album The Red Sea Sharks
    The Red Sea Sharks
    The Red Sea Sharks is the nineteenth of The Adventures of Tintin, a series of classic comic-strip albums written and illustrated by Hergé, featuring young reporter Tintin as a hero...

    (orig. "Coke en stock"), US Navy communicates by heliograph to bad man Rastapopoulos
    Rastapopoulos
    Roberto Rastapopoulos is a fictional character in The Adventures of Tintin, the series of classic Belgian comic books written and illustrated by Hergé. He is the antagonist in many of Tintin's adventures....

    .
  • In the television series Lost
    Lost (TV series)
    Lost is an American television series that originally aired on ABC from September 22, 2004 to May 23, 2010, consisting of six seasons. Lost is a drama series that follows the survivors of the crash of a commercial passenger jet flying between Sydney and Los Angeles, on a mysterious tropical island...

    , Benjamin Linus signals his people using a heliograph in the episode "There's No Place Like Home (Part 1)".

See also

  • Heliotrope (instrument)
    Heliotrope (instrument)
    The heliotrope is an instrument that uses a mirror to reflect sunlight over great distances to mark the positions of participants in a land survey. The heliotrope was invented by the German mathematician Carl Friedrich Gauss....

  • Semaphore line
  • Signal lamp
    Signal lamp
    A signal lamp is a visual signaling device for optical communication . Modern signal lamps are a focused lamp which can produce a pulse of light...

  • Telegraph hill
    Telegraph hill
    A telegraph hill is a hill or other natural elevation, chosen as part of an optical telegraph system because of the relatively great distance between it and at least one other point, which it may observe or be observed from...

  • Heliography
    Heliography
    Heliography is the photographic process invented by Joseph Nicéphore Niépce around 1822, which he used to make the earliest known permanent photograph from nature, View from the Window at Le Gras . The process used bitumen , as a coating on glass or metal, which hardened in relation to exposure to...

    , an early photographic process invented by Joseph Nicéphore Niépce around 1822


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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