Theodolite 2 : An instrument used in surveying to measure horizontal and vertical angles with a small telescope that can move in the horizontal and vertical planes
National Weather Service NWS Forecast Office, National Oceanic and Atmospheric Administration NOAA, SH Manual, Glossary of Hydrologic Terms, Washington, DC, USA 2015. http://www.nws.noaa.gov/om/hod/SHManual/SHMan014_g lossary.htm, (HydroI - Amer) {889}