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Automatic Telephone-Exchange System.

Description: Patent for "a simple system and arrangement which is especially adapted for a telephone exchange, which enables the instruments to be connected by a single wire, which dispenses with the use of an operator at the central station, which has automatic means for registering the messages sent by each subscriber, and which is provided with an automatic switching device by means of which one subscriber may connect with any other" (lines 10-19).
Date: December 5, 1893
Creator: Serdinko, John
Partner: UNT Libraries Government Documents Department

Traction Engine.

Description: Patent for an improved version of traction engine with ambulatory wheels that improve the design, including instructions and illustrations.
Date: December 12, 1916
Creator: Altgelt, Herman E.
Partner: UNT Libraries Government Documents Department
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