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Circuit-Closing Device for Doors.
Patent for a device mounted within a door jamb that closes or breaks a circuit when the door is opened or closed, respectively. The electrical connection can be used to turn on lights when the door is opened and off when closed.
Date:
November 4, 1913
Creator:
Fitch, William Hubert
System:
The Portal to Texas History
Matrix Molding Device.
Patent for improvements on matrix molding devices, "to provide simple devices or improvements in matrices of standard size and adaptation for use in linotype and other line casting machines for preparing the operating edges of printers' slugs for holding cross-rules" (lines 10-15), including illustrations.
Date:
November 4, 1918
Creator:
Markwell, Andrew E. & Evans, S. C.
System:
The Portal to Texas History