NA TURE 



501 



THURSDAY, APRIL 27, 1876 



"SCIENTIFIC WORTHIES" 



VII.— Sir Charles Wheatstoxe, Born February 

 1802, Died October 19, 1875 



CHARLES WHEATSTONE was the son of a music- 

 seller at Gloucester, where he was born in February 

 1S02, andwas educated at a private school in that city. 

 His father afterwards came to London, where he became a 

 teacher of the flute. He had, we bel eve, some share in 

 the musical education of the Princess Charlotte, a fact of 

 which he was never tired of boasting. In 1823 young 

 Wheatstone removed to London and commenced business 

 as a musical instrument maker, and in the same year made 

 what was probably his first contribution to scientific lite- 

 rature in a paper entitled " New Experiments on Sound," 

 contributed to Thomson's " Annals of Philosophy." In 

 1827 he contributed to the Quarterly Joicrtial of Scietice 

 an account of " Experiments on Audition," and a descrip- 

 tion of the beautiful toy known as the Kaleidophone. In 

 1832 he read an important paper to the Royal Society, 

 " On the Acoustic Figures of Vibrating Surfaces." In 

 this memoir the author gave for the first time the laws 

 of formation of the varied and beautiful figures dis- 

 covered by Chladni. He continued for several years to 

 devote his attention to Sound, and subsequently to Light. 

 He was appointed Professor of Natural Philosophy in 

 King's College, London, in 1834, and in the same year 

 made his celebrated experiments on the velocity of an 

 electric discharge by the aid of revolving mirrors. 

 Wheatstone does not seem to have lectured regularly at 

 King's College, and many of his discoveries were 

 described to the world by Faraday at the Royal Institu- 

 tion. Indeed he was not well adapted for public lecturing ; 

 he was so nervous that even in a very small company he 

 usually sat silent. Though his discoveries have become 

 of such immense practical importance, Wheatstone him- 

 self was far from being a practical business man ; on this 

 account he often failed to reap the substantial fruit 

 of his discoveries. Wheatstone was married oa Feb. 12, 



1847. 



Wheatstone's name is intimately connected with the 

 early history of Spectrum Analysis. In a paper read in 

 1835, ''On the Prismatic Analysis of Electric Light" at 

 the Dublin meeting of the British Association, he an- 

 nounced the existence of rays of definite refrangibility, 

 emitted in the volatilisation of metals by the electric 

 spark- He showed that the spectrum of the electric spark 

 from different metals presented each a definite series of 

 lines differing in colour and position from each other, and 

 that these appearances afforded the means of distinguish- 

 ing the smallest fragment of one metal from that of 

 another. " We have here," he wrote, " a mode of dis- 

 criminating metallic bodies more readily than that of 

 chemical examination, and which may hereafter be em- 

 ployed for useful purposes." These last words furnish 

 the keynote to all Wheatstone's work ; however valuable 

 may be the services he has rendered to pure science, his 

 c^r^at ultimate aim was the useful and practical. It was at 

 You XIII.— No. 339 



the meeting of the British Association in 1838 that he 

 described and exhibited the newly-invented stereoscope, 

 and at the 1848 meeting he described his " polar clock," 

 an instnmient for ascertaining the time by means of the 

 change in the plane of polarisation of the light of the 

 sky in the direction of the pole. One of these instruments, 

 we believe, has been sent out with the Arctic Expedition. 

 Wheatstone's description of the rheostat, and of the well- 

 known " bridge " which bears his name, is printed in the 

 Transactions of the Royal Society iox 1843. Indeed, it is a 

 popular error to suppose that Wheatstone's scientific fame 

 rests solely on his connection with the electric telegraph ; 

 he would have deserved an honourable place in the annals 

 of science had this practical application of electricity 

 been yet undiscovered. In the Catalogue of the Royal 

 Society alone will be found the titles of upwards of thirty 

 papers by him, not to mention many others scattered 

 about in various publications. 



The President of the Italian Society ot Science, of 

 which he was made an honorary member in 1867, said, in 

 conferring the honour, that the applications of the prin- 

 ciple of the rotating mirror are so important and so 

 various that this discovery must be considered as one 

 of those which have most contributed in these latter 

 times to the progress of experimental physics. " The 

 memoir on the measure of electric currents and all ques- 

 tions which relate thereto and to the laws of Ohm has 

 powerfully contributed to spread among physicists the 

 knowledge of these facts and the mode of measuring 

 them with an accuracy and simplicity which before we 

 did not possess. All physicists know how many re- 

 searches have since been undertaken with your rheostat 

 and with the so-caUed ' Wheatstone Bridge,' and how 

 usefully these instruments have been applied to the 

 measurement of electric currents, of the resistance of 

 circuits, and of electro-motive forces." 



With regard to the scientific value of the revolving 

 mirrors, IvI. Dumas spoke as follows in the address which 

 he gave at the obsequies of Wheatstone in Paris :— " This 

 admirable method enabled Arago to trace with a certain 

 hand the plan of the fundamental experiment which 

 should decide whether light is a body emanating from the 

 sun and stars or an undulating movement excited by 

 them. Executed by an accomplished experimenter, it 

 proved that the theory of emission was wrong. This 

 method has then furnished to the philosophy of the 

 sciences the certain basis on which rest our ideas of the 

 nature of the forces, and especially of that of light. By 

 means of this or some other analogous artifice, we can 

 even measure the speed of light by experiments purely ter- 

 restrial, which, pursued by an able physicist, have guided 

 the measure of the distance between the earth and the 

 sun." 



As to Wheatstone's connection with the electric tele- 

 graph, it is unnecessary for us here to speak, as this was 

 so fully gone into in the series of articles on " The Pro- 

 gress of the Telegraph," in vols. xi. and xii. of Nature. 

 De la Rive, in his " Treatise on Electricity," (Part VII., 

 Chap, I.), states so fairly Wheatstone's connection with 

 telegraphy, that we quote here what he says : — 



" The philosopher who was the first to contribute by his 

 labours, as ingenious as they were persevering, in giving 

 to electric telegraphy the practical character that it now 



