William Thomson, 1st Baron Kelvin From Wikipedia, the free encyclopedia

Thomson became scientific adviser to a team with Whitehouse as chief electrician and Sir Charles Tilston Bright as chief engineer but Whitehouse had his way with the specification, supported by Faraday and Samuel F. B. Morse.

Thomson sailed on board the cable-laying ship Agamemnon in August 1857, with Whitehouse confined to land owing to illness, but the voyage ended after just 380 miles when the cable parted. Thomson contributed to the effort by publishing in the Engineer the whole theory of the stresses involved in the laying of a submarine cable, and showed that when the line is running out of the ship, at a constant speed, in a uniform depth of water, it sinks in a slant or straight incline from the point where it enters the water to that where it touches the bottom.

Thomson developed a complete system for operating a submarine telegraph that was capable of sending a character every 3.5 seconds. He patented the key elements of his system, the mirror galvanometer and the siphon recorder, in 1858.

However, Whitehouse still felt able to ignore Thomson's many suggestions and proposals. It was not until Thomson convinced the board that using a purer copper for replacing the lost section of cable would improve data capacity, that he first made a difference to the execution of the project[19].

The board insisted that Thomson join the 1858 cable-laying expedition, without any financial compensation, and take an active part in the project. In return, Thomson secured a trial for his mirror galvanometer, about which the board had been unenthusiastic, alongside Whitehouse's equipment. However, Thomson found the access he was given unsatisfactory and the Agamemnon had to return home following the disastrous storm of June 1858. Back in London, the board was on the point of abandoning the project and mitigating their losses by selling the cable. Thomson, Cyrus Field and Curtis M. Lampson argued for another attempt and prevailed, Thomson insisting that the technical problems were tractable. Though employed in an advisory capacity, Thomson had, during the voyages, developed real engineer's instincts and skill at practical problem-solving under pressure, often taking the lead in dealing with emergencies and being unafraid to lend a hand in manual work. A cable was finally completed in August 5.

Thomson's fears were realised and Whitehouse's apparatus proved insufficiently sensitive and had to be replaced by Thomson's mirror galvanometer. Whitehouse continued to maintain that it was his equipment that was providing the service and started to engage in desperate measures to remedy some of the problems. He only succeded in fatally damaging the cable by applying 2,000 V. When the cable failed completely Whitehouse was dismissed, though Thomson objected and was reprimanded by the board for his interference. Thomson subsequently regretted that he had acquiesced too readily to many of Whitehouse's proposals and had not challenged him with sufficient energy.

A joint committee of inquiry was established by the Board of Trade and the Atlantic Telegraph Company. Most of the blame for the cable's failure was found to rest with Whitehouse. The committee found that, though underwater cables were notorious in their lack of reliability, most of the problems arose from known and avoidable causes. Thomson was appointed one of a five-member committee to recommend a specification for a new cable. The committee reported in October 1863.

In July 1865 Thomson sailed on the cable-laying expedition of the SS Great Eastern but the voyage was again dogged with technical problems. The cable was lost after 1,200 miles had been laid and the expedition had to be abandoned. A further expedition in 1866 managed to lay a new cable in two weeks and then go on to recover and complete the 1865 cable. The enterprise was now feted as a triumph by the public and Thomson enjoyed a large share of the adulation. Thomson, along with the other principals of the project, was knighted on November 10, 1866.

To exploit his inventions for signalling on long submarine cables, Thomson now entered into a partnership with C.F. Varley and Fleeming Jenkin. In conjunction with the latter, he also devised an automatic curb sender, a kind of telegraph key for sending messages on a cable.

Later expeditions

Thomson took part in the laying of the French Atlantic submarine communications cable of 1869, and with Jenkin was engineer of the Western and Brazilian and Platino-Brazilian cables, assisted by vacation student James Alfred Ewing. He was present at the laying of the Pará to Pernambuco section of the Brazilian coast cables in 1873.

Thomson's wife had died on June 17, 1870 and he resolved to make changes in his life. Already addicted to seafaring, in September he purchased a 126-ton schooner, the Lalla Rookh and used it as a base for entertaining friends and scientific colleagues.

In June 1873, Thomson and Jenkin were onboard the Hooper, bound for Lisbon with 2,500 miles of cable when the cable developed a fault. An unscheduled 16-day stop-over in Madeira followed and Thomson became good friends with Charles R. Blandy and his three daughters. On May 2, 1874 he set sail for Madeira on the Lalla Rookh. As he approached the harbour, he signalled to the Blandy residence Will you marry me? and Fanny signalled back Yes. Thomson married Fanny, 13 years his junior, on June 24, 1874.

Thomson's tide-predicting machine

Thomson introduced a method of deep-sea sounding, in which a steel piano wire replaces the ordinary land line. The wire glides so easily to the bottom that "flying soundings" can be taken while the ship is going at full speed. A pressure gauge to register the depth of the sinker was added by Sir William.

About the same time he revived the Sumner method of finding a ship's place at sea, and calculated a set of tables for its ready application.

His most important aid to the mariner is, however, the adjustable compass, which he brought out soon afterwards. It is a great improvement on the older instrument, being steadier, less hampered by friction, and the deviation due to the ship's own magnetism can be corrected by movable masses of iron at the binnacle.

Sir William was an enthusiastic yachtsman. His interest in all things relating to the sea perhaps arose, or at any rate was fostered, by his experiences on the Agamemnon and the Great Eastern. Charles Babbage was among the first to suggest that a lighthouse might be made to signal a distinctive number by occultations of its light; but Sir William pointed out the merits of the Morse code for the purpose, and urged that the signals should consist of short and long flashes of the light to represent the dots and dashes.