3 Matching Results

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Calculator (open access)

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
Concentration of Ores. (open access)

Concentration of Ores.

Patent for improvements to recovering ore using flotation methods.
Date: December 17, 1918
Creator: Wiser, Oba
System: The Portal to Texas History
Screw-Driver (open access)

Screw-Driver

Patent for a screwdriver. Illustrations included.
Date: December 29, 1908
Creator: Winfrey, Edgar M. & Lilins, Thomas W.
System: The Portal to Texas History