In Cambridge science had progressed little since the days of Newton. Thomson, therefore had recourse to Paris and for a year worked in the laboratory of Regnault, who was engaged in his classical researches on the thermal properties of steam; but his stay in Paris was comparatively short, for in 1846, when only twenty-two years of age, he accepted the chair of Natural Philosophy in the University of Glasgow, which he filled for fifty-three years, attaining universal recognition as one of the greatest physicists of his time.
The Glasgow chair was a source of inspiration to scientific men for half a century, and many of the most advanced researches grew out of the suggestions which Thomson scattered as sparks from the anvil.
Although his contributions to thermo-dynamics may properly be regarded as his most scientific work, it is in the field of electricity, especially in its application to submarine telegraphy, that Lord Kelvin is best known.
From 1854 he is most prominent among telegraphists. The stranded form of the conductor was due to his suggestion, but it was in the letters which he addressed in November and December of that year to Prof. Stokes, and which were published in the proceedings of the Royal Society for 1855 that he discussed the mathematical theory of signalling through submarine cables, and enunciated the conclusion that in long cables retardation due to capacity must render the speed of signalling inversely proportional to the square of the cable’s length.
Some held that if this were true ocean telegraphy would be impossible, and sought in consequence to disprove Thomson’s conclusions. Thomson on the other hand set to work to overcome the difficulty by improvement in the manufacture of the cables, and first of all the production of copper of high conductivity, and the construction of apparatus which would readily respond to the slightest variation of the current in the cable.
The mirror galvanometer and the siphon recorder, which was patented in 1867, were the outcome of these researches, but the scientific value of the mirror galvanometer is independent of its use in telegraphy, and the siphon recorder is the direct precursor of one form of galvanometer (d’arsnovals), now commonly used in electric laboratories.
Thomson’s work in connection with telegraphy led to the production in rapid succession of instruments adapted to the requirements of the time, for measurements of every electrical quantity, and when electric lighting came to the front, a new set of instruments was produced to meet the needs of the electrical engineer.
His industry is universal, and he seems to take rest by turning from one difficulty to another, difficulties that would appal most men, and be taken as an enjoyment by no one else.
This life of unwearied industry and of universal honour has left Lord Kelvin with a lovable nature, and charms all with whom he comes in contact.
In 1866 he received the honour of knighthood in acknowledgment of his services to transatlantic telegraphy, and in 1892 he was raised to the peerage, with the title of Baron Kelvin of Largs.