This Day in Geek History: February 4
1847
In Maryland, the first telegraph company is established.
1890
Thomas Alva Edison is issued a patent for the Quadruplex Telegraph. (US No. 420,594) This new telegraph is designed to transmit and receive four independent signals over a single wire, two in one direction and two in the opposite direction. The separate transmitting keys transmit a signal with either a high or low current strength which is then received with sounders that respond only the high or the low strength signal. Read more about the Quadruplex Telegraph at the Edison Papers website.
1902
Thomas Alva Edison is issued a patent for a Reversible Galvanic Battery, a battery with a revolutionarily large capacity for its weight. (US No. 692,507) It makes use of Cadmium as the oxidizable element, an oxide of Cobalt or Nickel as its depolarizer, and flakes of a conducting substance, such as Graphite.
1936
Radium E, the first synthetic radioactive substance, is first produced in the US by Dr. John Jacob Livingood at the University of California at Berkeley by bombarding the element Bismuth with neutrons.
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At the age of only fifteen,
The unmanned Soviet spacecraft