In a hydrometer analysis, 0.5 N of soil was mixed in water to form one litre of uniform suspen- sion. The corrected hydrometer reading after a lapse of 60 min. from the start of sedimentation was 1.010, and the corresponding effective depth was 10.8 cm. The grain specific gravity was 2.72. Assuming the viscosity of water as 0.001 N-sec/m² and the unit weight of water as 9.8 kN/m³, determine the co-ordinates of the corresponding point on the grain-size distribution curve.