Meridian-Seeking Compass : A gyroscope compass that has the capability to return itself to the meridian if moved away by some disturbing force. (Bul D20)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}