The Marsh Cone (Marsh Funnel) is a precision instrument used for measuring the viscosity of grout, cement slurry, and drilling fluids in construction and geotechnical engineering applications. It consists of a cone 6 inches (152 mm) across and 12 inches (305 mm) in height, with a working volume of 1.5 litres. A discharge tube of 2 inches (50.8 mm) long and 3/16 inch (4.76 mm) internal diameter is fixed at the apex for controlled flow measurement.