Sperry Gyroscope Creagh-Osborne Marching Compass  

This is a Creagh-Osborne marching compass, manufactured by Sperry Gyroscope. It was originally filled with alcohol and then used as either a handheld compass, or as a sighting compass.

The alcohol is long gone, and the numbers engraved in the central disk are barely readable. 

  This compass contains radioactive elements.  It registered approximately 2800 CPM (about 2.8 mR/Hr) with the GM tube in contact with the glass face, and approximately 60 CPM at 12 inches.