Figure i . — Deleuil demonstrates his 

 electric light on the Place de la 

 Concorde in Paris, October 20, 

 1843. ¥vomV Illustration, 1843, vol. 

 2, p. 132. 



Although electric illumination could become com- 

 mercially practical only after mechanical energy had 

 been substituted for chemical energy in the trans- 

 formation that produced electrical energy, still, the 

 initial advances in the field of electrical light were 

 made with power from chemical cells. By mid- 

 century there were indications that such an application 

 of electricity might be coiximercially profitable but it 

 was clear that other sources of power had to be found. 



Shortly after the voltaic cell was devised, it was 

 found that the current from the cell could produce a 

 number of strange new physical and chemical effects. 

 Attempts to determine the different effects of x'oltaic 

 electricity included studying the sparks obtained 

 between various materials, which, Humphrey Davy 

 found, became much brighter with charcoal than 

 with metals. Using a battery of 500 double plates 

 at the Royal Society, Davy announced in December 

 1808 that a glowing arc almost an inch long could be 

 obtained in this manner. By using a 2,000-plate 

 battery at the Royal Institution the following year, 

 he obtained an arc three inches long.^ In spite of 



1 Humphrey Davy, "An Account of Some Experiments on 

 Galvanic Electricity, Made in the Theater of the Royal 

 Institution," Journal of the Royal Institution of Great Britain, 

 1802, vol. 1, pp. 165-167; "An Account of Some New Analytical 

 Researches on the Nature of Certain Bodies, Particularly the 



its brilliance, no efforts were made to use the newly 

 found "electric light" because of its impermanence. 



At the same time, another source of electric light 

 had been suggested in the incandescent glow of 

 fine metallic wires when heavy currents go through 

 them. But the same problems were found to occur 

 with incandescent filaments as with arcs from char- 

 coal. Up to the 1840"s, any attempt to use the gal- 

 vanic current as a practical source of light was futile 

 because of the too-rapid consumption of the charcoal 

 or of the incandescent wire and because the current 

 from the chemical battery lasted for only a short 

 time. An additional difficulty in using charcoal in 

 an arc was that of maintaining the correct separation 

 of the electrodes in the face of rapid and irregular 

 burning. 



The 19th century saw much experimentation and 

 progress in public illumination, and after the invention 

 of the Bunsen and the Grove cells experimenters 

 began to examine seriously the possibility of using the 

 new agency for this purpose. Some of the first 

 successful attempts were made by the Parisian instru- 



Alkalies, Phosphorus, Sulphur, Carbonaceous Matter, and 

 the Acids Hitherto Undecompounded; with Some General 

 Observations on Chemical Theory," Philosophical Transactions, 

 1809, vol. 99, pp. 39-104. Philosophical Magazine, 1810, vol. 

 35, p. 463. 



PAPER 30: DEVELOPMENT OF ELECTRICAL TECHNOLOGY IN THE 19TH CENTURY: III 



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