PMT_History_Notes      Bell_System


~1462~  Columbus Discovers New World 

~1750~  Static Storage Cell - USA Benjamin Franklin

~1776~ Declaration of Independence

~1790~ U.S. Patent Act

~1800~  Chemical Battery - Alessandro Volta

~1825~  Electromagnetism -  William Sturgeon (British)

~1830~  Door Bell -  USA  Joseph Henry

~1835~  Morse Code Telegraph

~1861~ Civil War - War Between the States

~1869~  Gray and Barton - telegraph and electrical supplies - Inventor Elisha Gray and Manufacturer Enos M. Barton

~1872~  Western Electric -  Gray and Barton was purchased by Western Union and renamed Western Electric

~1874~  Teletype ~1845-1855-1875~

~1876~  Telephone Invented by both Bell and Gray

~1877~  Bell Telephone Company - Alexander Graham Bell

~1877~  Phonograph Invented by Thomas Edison

~1878~  First Commercial Telephone Exchange in New Haven, Connecticut

~1879~  Bell sued Gray- ie. Western Electric/Western Union

~1879~  Exchanges, first in Richmond, then later Petersburg, Norfolk, Lynchburg, Danville Virginia
              to become Southern Bell Telephone and Telegraph company

~1880~  Light Bulb Invented by Thomas Edison

~1881~  Load Coil invented by Oliver  Heaviside

~1881~  American Bell Telephone Company

1882~  Bell/Gray Settlement - American Bell Telephone Company became part-partners
              ie. part owners of  Western Electric/Western Union   

~1885~   The American Telephone and Telegraph Company was incorporated on March 3, 1885

~1887~  Elisha Gray - invented the telautograph  ie. fax machine

~1888~  Stepper Switch or Strowger Switch - Almon Brown Strowger 

~1889~  Bell System - Blue Bell Logo until ~1900~

~1892~  Bell completed a long distant call from NYC to Chicago with the invention of loading coils without the vacuum tube invention. 

~1907~  Triode Vacuum Tube

~1910-  Pioneers of the Telephone Industry organized.

~1915~  First Coast-to-Coast Call

~1925~  Canadian physicist Julius Edgar Lilienfeld patented the FET

~1934~ German inventor Oskar Heil patented a similar device but neither found any practical use

~1940's~  Dial Tone

~1947~  John Bardeen, Walter Brattain. William Shockley worked on gold point contact crystal germanium
              at Bell Labs invented a point contact transistor effect, or transistor that became a practical device.


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