As the earliest settlers in South Australia spread out across the vast landscape, building huts and shelters in the midst of acreages broad enough to support only a small family, their isolation was profound. They had no means of communicating with each other without riding or walking for many kilometres across dusty, thorny bushland, often through ferocious heat, torrential rain or savage wind.

View from the Dares Hill Drive

Building the Line. The construction of the Overland Telegraph Line.

by Andrew Crouch.

From the diaries of the men involved in the construction, this well illustrated book gives a detailed look at the men and the line itself.
Publication coincides with the 150th Anniversary of the momentous 1870 undertaking.

Read an Extract from the Book

The Electricity to run the Telegraph

Quoted from this article.

There was no electricity supply in South Australia until 1895, and no supply to the Mid North until the mid-1920's.

However, in 1830 Joseph Henry, then an instructor at the Albany Academy in New York was "responsible for major discoveries in electromagnetism, most significantly the means of constructing electromagnets that were powerful enough to transform electrical energy into useful mechanical work at a distance....."

"Henry tightly wound his horseshoe with several layers of insulated wire. In March 1829 he demonstrated an electromagnet with 400 turns, or about 35 feet, of insulated wire. This magnet, Henry remarked later, "possessed magnetic power superior to that of any before known."

"...Henry did set out to demonstrate the practicability of an electromagnetic telegraph immediately after his paper appeared. His prototype consisted of a small battery and an "intensity" magnet connected through a mile of copper bell-wire strung throughout a lecture hall. In between the poles of this horseshoe electromagnet he placed a permanent magnet. When the electromagnet was energized, the permanent magnet was repelled from one pole and attracted to the other; upon reversing battery polarity, the permanent magnet returned to its original position. ... Henry caused the permanent magnet to tap a small office bell. He consistently demonstrated this arrangement to his classes at Albany during 1831 and 1832."

Henry's horseshoe magnet of 1829

Henry's "Yale" magnet of 1831

Henry's one mile "telegraph" of 1831-32

The Invention of the Telegraph

An American, Samuel Finley Breese Morse, (1791-1872), spent 12 years from 1832 perfecting the electric telegraph, for which he received the patent.

His telegraph was the first device to send messages, using electromagnetism, by tapping out the 'Morse' code for each letter of the message with a telegraph key. The telegraph changed the dots and dashes of this code into electrical impulses and transmitted them over telegraph wires. A telegraph receiver on the other end of the wire converted the electrical impulses to dots and dashes on a paper tape.

Design of Samuel Morse's original telegraph

Design for a Strap Key 1844

Samuel Morse's embossing printer of 1836

The Code to send along a Telegraph Wire

In 1836, Samuel Morse also invented the Morse Code, which is a series of electrical signals. Short signals are referred to as dits (represented as dots). Long signals are referred to as dahs (represented as dashes). Morse code relies on precise intervals of time between dits and dahs, between letters, and between words.

A dit is 1 unit of time, a dah is 3 units of time, a pause between letters is 3 units of time and a pause between words is 7 units of time.

The speed of transmitting Morse code is measured in WPM (words per minute) with the word "Paris", which requires 50 units of time, used as the standard length of a word. If you transmitted the word "Paris" 5 times, you would be transmitting at 5 WPM. An experienced Morse code operator can transmit and receive information at 20-30 WPM.

The Introduction of the Telegraph to South Australia

During 1858 the first successful underseas telegraph cable was laid. Gutta percha, from the tree, Palaquium gutta, was found to be the most successful insulating material for the cable as, unlike rubber, it was hard but not brittle. An extract from the book "Caoutchouc and Gutta Percha" by Raimund Hoffer, written in 1883, can be read here. A readable, well illustrated online History of the Submarine Cable System can be read here.

Unfortunately, so many cables were laid that the source of gutta percha was eventually exhausted.

Great Eastern Laying Transatlantic Cable

The very first telegraph line in South Australia was a private line opened from Adelaide to the Port by James McGeorge in 1855. The Colonial Office in London had, however, recommended Charles Todd, so James McGeorge's line was bought out and dismantled. By 1858 a line to Melbourne had been built and a second, via Wellington was opened in 1861.

Telegraph lines followed the railway tracks as they were built, enabling essential communication between stations and also, of course, between remote townships. An excellent early map, large enough to be read, can be seen here

In addition to the need for almost instant internal communication within Australia, a submarine cable linking to the UK and Europe had been laid as far as Java. Unfortunately, in order to connect Australia's network to that cable, the previously inaccessible interior and north of Australia had to be explored and it was primarily for this reason that two expeditions set out to find both a route and sufficient timber across the centre of Australia. John McDouall Stuart succeeded after travelling 2900 kilometres from Adelaide to arrive at the Gulf of Carpenteria in 1862, but Burke and Wills, leaving from Menindee, failed to return.

Submarine Telegraph Cables in 1903

Camels carrying telegraph poles, late 19th century

The Northern Territory was transferred to South Australia in 1863, securing the land required for the telegraph line to the South Australian Government who agreed, in 1870, to construct 3200 km of line to Darwin, while the British-Australian Telegraph Company promised to lay the undersea cable from Java to Darwin.

The South Australian Superintendent of Telegraphs, Charles Todd, was appointed head of the project. The telegraph line was constructed using more than 30,000 wrought iron poles, insulators, batteries, wire and other equipment, imported from England. The poles were placed 80 m apart and repeater stations were built every 250 km.

The logistics of such a lengthy construction across virtually unknown territory called for convoys of horses, bullocks and carts loaded with provisions and equipment for many weeks, all taking enormous amounts of time to travel across the inhospitable landscape to the construction teams.

The undersea cable from Java reached Darwin on 18 November 1871 and was connected to the completed Northern end of the line the following day.

The North and South lines were finally joined at Frew's Ponds on Thursday, 22 August 1872.

Aboriginal Fire Trees
West of Middle Road
North of Port Germein Gorge Road