Used to determine the in-situ density of fine graded compacted or bonded soil. The apparatus is placed over the hole excavated in the soil, and water is pumped into a rubber balloon and forced into the hole. The amount of water displaced into the baloon is measured from the graduation of the scale. The instrument consists of a graduated plexiglass cylinder 1600 ml. capacity, fitted in a corrosion resistant frame, a rubber pump with stop valve, a density plate and 12 rubber balloons.