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Filed: Sep. 8, 1903
Issued: Nov. 14, 1911
Inventor: John C. Wilson
Wilson designed his invention with a specific business in mind--the telephone company. He believe his devices could be "adapted for use in connection with telephone toll lines switchboards to record the exact time when a toll line conversation begins and when it ends and at the same time to automatically compute or calculate and record the exact elapsed or intervening time, or to indicate that the elapsed or intervening time has not exceeded a certain fixed or predetermined period or time limit."
Image taken from U.S. Patent 1,008,763 - Digitized by Google