This model clinometer used in both WW1 and WW2 for checking artilllery and mortar barrel anglesPrecision instrument widely used by Alliied forces in two warsMetal with some parts painted black. Device comprises a segment of a circle with an adjustable radial arm with bubble level on a slide attached"Clinometer Field Mark VI No. A.221" Noblet and Forrest 1941" "Direction of Target" with arrow. "Use this Base for 0° - 45°" "45° - 90° Target" with arrow Circle segment graduated with 0 - 44 degrees on side, 45 - 89 degrees other side. Arm graduated 0 - 60 minutes both sides clinometer, artillery instruments