28 IOWA ACADEMY OF SCIENCES. 



galvanometer, all of these men, devoted solely to knowl- 

 edge for knowledge sake, are sharers with Morse and 

 Vail in the glory of the invention of the telegraph. 



And so with wireless telegraphy. In Marconi's hand this 

 invention blazes with a sndden brilliance which attracts 

 the attention of the world, but the torch has been con- 

 veyed to him along the line of many runners in the torch- 

 race of scientific discovery. From Clerk Maxwell who 

 showed the analogy between electricity and light, from 

 Hertz, with his demonstration of electro-magnetic waves, 

 from Onesti, of Fermo, and Branly, of Paris, and Lodge, of 

 London, whose researches produced in the coherer an 

 instrument capable of seeing such waves, from these and 

 others the torch was passed on to the great inventor whose 

 improvements in apparatus made effective the discoveries 

 of science. 



In the telephone at least four scientific principles are 

 involved — the voltaic current, the interaction of mag- 

 netism and electricity, the temporary magnet and the 

 microphonic action of carbon. Through this marvelous 

 invention each master in electrical science from the time 

 of Galvani, who has aided in the elucidation of these prin- 

 ciples, though dead, yet speaketh. 



Thus w^e may fairly claim that to science in large 

 measure is due the plexus of post, telegraph and telephone, 

 by which intelligence is flashed throughout the body social 

 even more swiftly than along the nerves of the body phys- 

 iologic. And how incalculable is the service which science 

 thus renders. Consider the extent of the channels of com- 

 munication. The domestic mail service of the United 

 States requires each year twenty-one million miles of 

 travel. Sixty-four years ago the first commercial telegraph 

 was built with a length of forty miles. At the close of the 

 century there are not less than one million miles of tele- 

 graph in the United States, over which duplex and mul- 

 tiplex messages are carried at the same time, and the rate 

 of transmission has risen to six thouand signals per min- 

 ute. One hundred and seventy thousand miles of sub- 

 marine cables moor coasts, islands and continents toe^ether. 



