Improvement in Key-Hole Guards.
Description:
Patent for "a guard for key-holes of locks, to prevent the use of keys by unauthorized persons, the picking of the lock, and as a means for operating the bolt when fitted for that purpose." (Lines 7-11) Includes instructions and illustrations.
Date:
December 23, 1873
Creator:
Hall, William N.
Partner:
UNT Libraries Government Documents Department