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September 2015
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Computer Networking and Telecommunications Research

The Trans-Atlantic Telegraph Cable
150th Anniversary Celebration 1858-2008

Professor Nigel Linge, University of Salford

In 1858 the electric telegraph based on the system developed by Samuel Morse and his famous code was in widespread use in many countries, most notable of which were the UK and America .However, building a truly global communications telegraph network required the linking of the ‘old’ and ‘new’ worlds and that required bridging the Atlantic Ocean.An alternative, the Siberian Telegraph, was considered because this offered a predominantly land based route but even this required laying cables in the sea, albeit over considerably shorter distances. The major difference between a land and sea based route is that cables that operate underwater need to be insulated and protected from corrosion.

Gutta Percha

Underwater cables need an insulator that can remain impervious under the high pressures on the sea bed and also resist attacks from marine plants and animals.The solution to these problems was found in Gutta-percha.Gutta-percha is a genus of tropical trees found in Southeast Asia.The resin from these trees turned out to have exactly the right properties required for underwater cables.

Underwater cables

Trials of underwater cable had been undertaken by Samuel Morse across New York Harbour in 1842 and Charles Wheatstone across Swansea Bay in 1844.Neither of these used Gutta-percha; that was completed in 1849 by Charles Walker.The first Gutta-percha cable linked a ship to a land based station which connected to the South-Eastern Railway Company’s telegraph network.This first demonstration of the success of Gutta-percha inspired Jacob and John Watkins Brett to undertake the laying of a telegraph cable across the English Channel.Their General Oceanic and Submarine Telegraph Company was formed in 1846 and ordered 40km of cable; this cable had a central copper conductor that was insulated by a 12mm thick covering of Gutta-percha.The cable was laid by the steam ship Goliath in 1850 and connected to telegraph networks in Dover and Cape Gris Nez.Unfortunately this first cable failed very quickly because it was dragged by a ship’s anchor.Here again is another example of the perils of laying cables underwater.Not only do cables need to be insulated from the underwater environment but also from damage caused by passing ships.Cables therefore also needed to be reinforced and it was common practice that the shore ends of cables or those laid in shallow water had to be physically stronger than deep sea sections.The failure of the 1850 cable was followed by a successful second cable in October 1851.

A cable linking Donaghadee in Ireland and Portpatrick in Scotland was completed in 1853.These successes were followed by many other operational telegraph cables including those laid between Dover and Ostend, Sweden and Denmark , Genoa to Corsica to Sardinia to Algeria , and Orfordness ( Suffolk) to the Hague.In 1852 Franis N Gisbourne laid the first undersea cable in North America across the Northumberland Strait from Prince Edward Island to the mainland of New Brunswick province.The next step was to be a cable connecting Newfoundland to New York however, the company ran out of money.It was at this point that a New York paper merchant, Cyrus Field, became interested in the venture.

The Trans-Atlantic Cable Proposition

Cyrus Field was interested in laying a telegraph cable from New York to Newfoundland for this offered a shorter route across the Atlantic to Ireland . Thus the New York, Newfoundland and London Telegraph Company was formed in 1854.Working with Samuel Morse and the Brett brothers the company was successful in laying a cable from Cape Breton, Nova Scotia to Cape Ray on the west coast of Newfoundland in 1855.This cable was built to the same specification as that laid across the English Channel.

The next challenge was to lay a 400 mile cable across Newfoundland to St John’s on its east coast. This was completed in 1856 and the end of this cable was a telegraph station at Trinity Bay.

Now all that remained to completing a telegraph line linking the old and new worlds was the Atlantic Ocean.

A survey of the Atlantic Ocean between Ireland and Newfoundland had already been completed by the US Navy and that had proved that between 48 and 55 degrees of latitude north the seabed was flat at a depth of 2,000 fathoms (approximately 2 miles). Therefore, this would be the trans-Atlantic telegraph cable route, some 1,600 miles in length. Achieving a venture of this magnitude was going to require significant investment and the most logical source of that funding was the UK .

Cyrus Field formed The Atlantic Telegraph Company on 6th November 1856 in London. A total of 345 investors were sought who were prepared to contribute £1,000 to the venture. One of these was the Manchester cotton merchant, John Pender.

John Pender

Working in Manchester John Pender had formed “John Pender and Company” as a distributor of products to the looms of Lancashire and Scotland . However, in 1852 John Pender had invested in the creation of the English and Irish Magnetic Telegraph Company to lay a telegraph cable across the Irish Sea. In 1856 the company merged with the British Telegraph Company to become the British and Irish Magnetic Telegraph Company.

On the 9th December 1856, The Atlantic Telegraph Company held its first general meeting and John Pender was elected a Director.

Manufacturing the Cable

An order to manufacture 2,500 miles of Atlantic Cable was placed with the Gutta-Percha Company who would be responsible for the insulated core which comprised seven copper wires of number 22 gauge twisted together insulated with three layers of Gutta-Percha. The Gutta-Percha Company had been formed in 1845 and the Atantic Telegraph Cable was manufactured at its Wharf Road works in London.

The outer protective layer of the cable comprised eighteen strands of wire each comprising seven charcoal annealed iron wire of number 22 gauge giving an overall cable diameter of approximately three quarters of an inch. For each mile of telegraph cable, a total of 133 miles of wire was needed and the total weight was approximately one ton per mile.Contracts for providing this outer protective layer were awarded to R.S. Newhall of Birkenhead and Glass, Elliot & Co., Greenwich. Each was responsible for 1,250 miles of cable. Only one cable was required, the electrical return path was to be the earth.

The 1857 Expedition

The first attempt to lay the Atlantic Telegraph cable was undertaken in 1857. The UK Government provided HMS Agamemnon (3,102 tons, 230 feet x 55.5 feet) a steam and sail powered battleship and the US provided the steam frigate Niagara which was the largest navy ship in the world at 345 feet long, 55 feet wide and 5,800 tons. The Agamemnon sailed to Greenwich where it collected the portion of cable manufactured by Glass, Elliot & Co., whilst the Niagara sailed to Birkenhead to collect the cable from R.S.Newall.

The two halves of the cable met for the first time on 31st July 1857 when the two ships arrived at Queenstown Harbour on the south coast of Ireland. These two ships and several support vessels then sailed to Valentia Island on the west coats of Ireland and the most westerly point of Europe. It was here that the shore end of the cable was brought ashore.

With the shore end of the cable landed, the cable laying ships then set sail towards Newfoundland on 7th August 1857. Niagara led the way with Agamemnon following; the plan being that once the cable stored on Niagara had been laid, then Agamemnon would take over somewhere mid-Atlantic.

At eight miles the shore end of the cable, which was of a stronger construction, was spliced to the main Atlantic section. However, very soon the cable had broken and the ships had to halt whilst it was repaired. They resumed their mission however, having laid about 380 miles of cable, a problem developed with the cable laying machinery on the Niagara and it could no longer hold the weight of the cable. On 11th August, the cable snapped. The ships had to return and an inquiry was held on 20th August to asses what had gone wrong. One conclusion arising from this was that any future expedition should commence mid-ocean with the two ships splicing their respective halves before sailing in opposite directions towards Newfoundland and Ireland .

The Niagara and Agamemnon returned to Keyham Dockyard (Devonport) where they unloaded their cables and then returned to normal duties.

Sir William Brown, Chairman of the Atlantic Telegraph Company wanted to abandon the venture and sell off the surplus cable. However, the Company still had over 2,000 miles of cable available and John Pender proved influential in convincing the Company that the best course of action was to mount a second attempt.

The 1858 Expedition

By the end of 1857 The Atlantic Telegraph Company had only £46,000 left in the bank, having spent £300,000 on their first failed attempt. However, they did also have over 2,000 miles of cable safely stored at Keyham Dockyard. Having decided on a second attempt new shares in the company were issued at the value of £20 each to raise much needed additional capital and an order for a further 900 miles of cable was placed with Glass, Elliot & Co. The machinery for laying the cable on-board the ships was redesigned and both the American and UK Governments re-confirmed the availability of the Niagara and Agamemnon.

In April 1858 the Niagara and Agamemnon arrived in Keyham Dockyard and started loading the cable.

On the 10th June 1858 these two ships and their support vessels set sail for mid-Atlantic; the plan this time was to start in the middle and work outwards towards Valentia Bay and Trinity Bay. The cable would also remain connected between the two ships which offered the added advantage of being able to continually test it.

Shortly after setting sail the ships encountered a severe storm. The Niagara was able to weather the storm without too much difficulty but the Agamemnon suffered greatly almost at one point capsizing.

The coal stored in its bunkers burst out shedding tons of fuel across the lower decks of the ship. Part of the Atlantic cable also became dislodged.

At one point it looked as though the cable would have to be sacrificed to save the ship but fortunately, the storm abated and on 25th June 1858, the Agamemnon was able to meet the Niagara at the pre-arranged rendezvous point. The two pieces of cable were joined together on board the Agamemnon and the ships began to sail apart. It broke twice, each time requiring the vessels to return to their starting points and re-commence the process. The third attempt commenced on 28th June 1858 and with the Agamemnon still in a bad condition from the effects of the storm and now running low on supplies, everyone thought that this was their last chance. At just over 100 miles apart disaster struck, the cable snapped as it left the Agamemnon. Now, using its sails in order to save coal, the Agamemnon limped back to the rendezvous point. However, with the cable broken, the two ships could not communicate and so the Niagara had no idea what the Agamemnon’s intentions were. Following a pre-arranged plan for situations such as this, the Niagara had in fact returned to Ireland . On the 12th July 1858 the Agamemnon limped back into port to join the Niagara.

On the 17th July the two ships had been re-stocked with supplies and set sail once again for their mid-Atlantic starting point, arriving there on the 29th July 1858. The same process was repeated and this time, the weather was kind. Indeed the laying of the cable worked perfectly with minor problems being quickly overcome.

On the 4th August 1858, the Niagara arrived at Trinity Bay being followed on the 5th August by the Agamemnon entering Valentia Bay; the cable had crossed the Atlantic! Now all that was required was to land the cable and connect it to the shore based telegraph stations.

The first complete message sent along the cable from Newfoundland to Valentia was on 12th August 1858 at 5:35pm. It read, “Laws, Whitehouse received five minutes signal. Coil signals too weak to relay. Try drive slow and regular. I have put intermediate pulley. Reply by coils”

Transmitting an electrical signal over this length of cable was difficult, the losses in the cable meant that the signal was very weak at the receiving end and dispersion resulted in a clean step change in the signal at the sending end becoming spread out and hence, much harder to distinguish at the receiving end. Dispersion means that more time must be left between Morse Code ‘dots’ and ‘dashes’ otherwise at the receiving end they will simply merge into each other and become indistinguishable. Consequently, the signalling rate over the cable was very low, being a few words per hour. It was Lord Kelvin (Professor William Thomson) who first studied this problem and presented his results in his paper, “On the theory of the electric telegraph” which was presented to the Royal Society in 1855. In 1858 he patented a new detector called a mirror galvanometer that was extremely sensitive and hence, able to respond to very small signals. As its name suggests it uses the received electrical signal to generate a magnetic field that moves a small mirror. A light beam reflecting off this mirror in effect magnifies the movements to make then discernable. Mirror galvanometers were used at each end of the Atlantic cable but even with these, sending messages remained problematic.


Progress of the Atlantic Telegraph had been eagerly followed on both sides of the Atlantic and needless to say, news of its success resulted in major celebrations.

Telegrams across the Ocean

The most famous messages sent over the Atlantic Cable were those between Queen Victoria and the American President James Buchanan.

Sending the Queen’s message was begun on 16th August but not completed until the 17th August 1858. It read…

“The Queen desires to congratulate the President upon the successful completion of this great international work, in which the Queen has taken the greatest interest. The Queen is convinced the President will join with her in fervently hoping that the electric cable which now connects Great Britain with the United States will prove an additional link between the two nations, whose friendship is founded upon their common interest and reciprocal esteem. The Queen has much pleasure in thus directly communicating with the President, and in renewing to him her best wishes for the prosperity of the United States .”

On 19th august 1858, the President’s response was transmitted from Newfoundland. It read . . .

“To Her Majesty, Victoria, Queen of Great Britain . The President cordially reciprocates the congratulations of Her Majesty, the Queen, on the success of this great international enterprise, accomplished by the science, skill, and indomitable energy of the two countries. It is a triumph more glorious, because far more useful to mankind, than ever won by conqueror on the field of battle. May the Atlantic Telegraph, under the blessing of Heaven, prove to be a bond of perpetual peace and friendship between the kindred nations, and an instrument designed by Divine Providence to diffuse religion, civilization, liberty, and law throughout the world. In this view will not all the nations of Christendom spontaneously unite in the declaration, that it shall be forever neutral, and that its communications shall be held sacred in passing to the place of their destination, even in the midst of hostilities?”

Less famous was a message sent on the 31st August 1858 from Valentia to Newfoundland. It read . . .

“The Military Secretary to Commander in Chief Horse Guards, London. To General Trollope, Halifax, Nova Scotia. The sixty second regiment is not to return to England .”

This message, which prevented a large contingent of soldiers returning to England, saved the British Government £60,000 and underlined the commercial potential of an Atlantic telegraph cable.

In 23 days of operation a total of 271 messages totalling 14,168 letters were sent from Newfoundland to Valentia and 129 messages totalling 7,253 letters were sent from Valentia to Newfoundland.

However, on the 18th September 1858 the cable fell silent.

An abrupt end

The failure of the cable in service was traced to a fault 300 miles west of Valentia. Repair was impossible. Quite why the cable failed is open to debate with two main reasons being widely reported.

The first suggested that Edward Orange Wildman Whitehouse, chief electrician for the Atlantic Telegraph Company, had damaged the cable by subjecting it to too high a voltage. In the belief that the quality of the received signal could be improved by increasing the voltage at the transmitter he applied 2,000 volts at the Valentia end.

The second puts the blame on Glass, Elliott & Co., where, it is claimed, the cable was left outside in open air being subjected to the sun; the heating effect of which was amplified by the tar coating applied to the cable. The suggestion is that the cable got sufficiently hot to melt the Gutta-percha and hence, to weaken its insulation properties.

It may have ended in failure but the expeditions of 1857 and 1858 had proved that it was possible to manufacture, lay and operate an Atlantic Cable. In other words, it was a feasible and practical proposition. This momentous event is therefore a critical point in the story of telecommunications. In 1858 it was proven that it was possible to construct a global communications network and this laid the foundations of today’s Internet, World Wide Web and International telephone calls.

Further reading

“The Cable - the wire that changed the world”, Gillian Cookson, Tempus Publishing Limited, 2003, ISBN: 0 7524 2366 5

“Girdle Round the Earth – the story of Cable and Wireless”, High Barty-King, William Heinemann Ltd., 1979

“History, Theory and Practice of the Electric Telegraph”, George B Prescott, Ticknor and Fields, 1860, Reprinted by Frank Jones, September 1972.

“History of Telegraphy”, Ken Beauchamp, The Institution of Electrical Engineers, 2001, ISBN: 0 85296 792 6

“History of the Atlantic Cable & Undersea Communications from the first submarine cable of 1850 to the worldwide fiber optic network”, online at, accessed July 2008.

Transatlantic cable 150th anniversary.