56 SELLERS — TRANSMISSION OF ENERGY BY ELECTRICITY. [Feb. 3, 



an electric impulse around the globe, it was the impulse from 2, gal- 

 vanic battery. No dynamo had been used in place of a battery^ 

 although instruments had been constructed to demonstrate the fact 

 that the dynamo could be used. The electro-magnet was well 

 understood, the electric impulse had been made to give motion to 

 machines from electro-magnets and from permanent magnets, and 

 the relation of the various forms of energy, represented by lights 

 heat, magnetism, etc., were each and all known to be what has 

 since been termed ''modes of motiof." 



In the year 1876, marking a century in the age of our Republic^ 

 there was given to the world, through the grand Centennial Exhibi- 

 tion in Philadelphia, an object-lesson in the state of the arts and the ' 

 advance of knowledge. The buildings in Fairmount Park, how- 

 ever, were not lighted by electricity, although the arc light, with 

 clockwork to keep the carbons in proper relation to each other, was 

 used for experimental purposes long before. As to the use of the 

 arc light, on the 8th of December, 1858, the high light at South 

 Foreland was illuminated by an electric current generated by one of 

 Holmes' magneto-electric machines. In 1863 the electric light was 

 applied to the lighthouse at La Heve, France. The chemical action 

 of electricity was known when Carlyle and Nicholson discovered in 

 the year 1800 that water could, by means of electricity, be resolved 

 into its two component gases, oxygen and hydrogen, by means of 

 the voltaic pile. Sir Humphrey Davy by the same means, seven 

 years later, proved true Lavoissier's suspicion that the alkalies 

 potash and sodium were not simple bodies, but compound, by the 

 discovery of five new metals by electrolysis, viz., potassium, 

 sodium, barium, strontian and calcium. I shall refer to one of 

 these metals when I come to speak of the transmission of energy 

 from one common source of power in a condition ready for use, 

 either for turning the wheels of factories, for heating, lighting or 

 repeating Sir Humphrey Davy's process in the production of 

 sodium from an alkali, not as a laboratory experiment, but on a 

 commercial scale at the rate of many tons per day. 



In tracing the progress of knowledge bearing upon the transmis- 

 sion of energy by electricity, the United States Patent Office 

 records furnish much information of a historical character useful 

 for determining the chronological sequence of invention, and no 

 more interesting chapter in the history could be obtained than that 

 on the application of the modern dynamo by telegraph companies to 



