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Safety Device For Railway-Tracks
Patent for a safety device for railway tracks to prevent derailment. Illustrations included.
Date:
February 21, 1911
Creator:
Carlton, Robert Elliston & Ryle, Marcus Warland
System:
The Portal to Texas History
Calculator
Patent for a calculator which consists of semicircular device with movable pointers and number indexes printed on it that allows the pointers to be moved to different numbers to produce the answer to a math problem such as calculating the cost of goods sold by the pound in a store.
Date:
December 21, 1909
Creator:
Goss, George Wilson
System:
The Portal to Texas History