The Invention of the Telegraph

It took the genius of Gauss, probably the greatest mathematician who ever lived, to see the proper importance of the discoveries of Oersted: electric current – magnetic needle – telegraph. Gauss and his friend and colleague Professor Weber began experimenting on these lines and in 1832 the needle telegraph was completed. However, neither Gauss nor Weber had the time or inclination to concern themselves with the practical development of the electric telegraph. Samuel Morse, born in 1891 in Charlestown, Massachuchetts, after graduating from Yale, travelled through Europe in the late 1820s to study the various schools of painting in the countries of their origin. During these travels he became deeply impressed by the electro-magnetic experiments carried out in Europe, and during his return journey to the USA in 1832 he devised a new type of telegraph. In those days, there were vast technical difficulties which cannot easily be appreciated in our time. For instance, there was no such thing as insulated copper wire. Inventive as ever, Morse used the wire (insulated) used by New York milliners to make fashionable hats for society ladies. Morse did not use the magnetic needle; instead he employed an electro-magnet to press a pen against a paper strip which was unrolled slowly and uniformly. Short impulses on the transmitter resulted in dots on the strip and long impulses in dashes. Combinations of dots and dashes represented letters, numbers, and symbols; this was the Morse code, patented in 1840. With this apparatus Morse telegraphed, in his first tests in 1837, over a distance of ten miles. For six years he worked to improve his technique and his code, whereupon Congress in 1843 approved the installation of the world’s first telegraph line between Washington and Baltimore at a cost of $30,000. The line was officially taken into use on 24 May 1844. Werner von Siemens built the first telegraph connection in Europe (between Berlin and Frankfurt-am-Main) which was taken into use in 1849. Von Siemens still used the needle telegraph which he had improved. However, by the early 1850s the Morse telegraph system had became accepted worldwide as the (then) only reliable means of communication over long distances. When Morse died in 1872, the telegraph had already girdled the earth. At about the same time, the English physicist John Daniell developed a new primary battery, which is still in use and named after him. It is a non-polarizing cell with zinc (negative) and copper (positive) electrodes. The zinc plate is in a porous cup containing a weak zinc-sulphate solution; the cup is in a jar filled with a saturated copper sulphate solution in which the copper electrode is immersed. The e.m.f. of the cell is about 1.1 V. Another aspect of electricity that had the attention of researchers and technologists was lighting. The world had to wait for the incandescent lamp developed by Edison later in the century, but nevertheless in the middle of the century New York, London, Paris, Berlin, and some other cities had a kind of electric lighting in some important thoroughfares provided by arc lamps.

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