: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 sudden 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 we 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 tliouand signals per min- 
ute. One hundred and seventy thousand miles of sub- 
marine cables moor coasts, islands and continents together. 
