On this date in 1900 (February 12), Joseph Lees of Summit Hill, Pennsylvania received a U.S. Patent for his invention, a device to prevent nocturnal seminal emissions.  The device worn by a sleeping man would electrically activate a bell or other alarm when the man’s penis became erect thereby awakening the man and preventing the involuntary emission.

 
 
 
Source: SexPatentsTheBook.com