PTM OFFICE HISTORY Bell

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.

Bell_System_Overview this page

History

Patents

Four Stages

WECO - Elisha Gray_Gray&Barton_Western_Union

AT&T -2-

Wireless - Radio

studio page

humor

fcc_page

biography

Graybar - history

Learning Dial Tone Adventure

Shepherd Center Dial Tone MX XL+AD

LINKS-2

Sounds
Railroad Telegraph Radio Telegraph Dial Tone

Dial Pulse Touch Tone Dial-up Modem