A comparison of the drop-cone penetrometer and Casagrande methods for determining the liquid limit of soils showed that the former method is simpler, faster and provides more precise results.

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. Pore volume changes in a structured silt-loam soil during drying. Can. J. Soil Shrinkage and volumetric water content of undisturbed soil cores 150 mm diam. i 100 mm high from four horizons of a silt-loam, Orthic Humic Gleysol were monitored throughorit a drying cycle from saturation to oven dryncss. Drying from saturation to -100 kl)a waiUy deiorption apparatus. Subsequently the cores were subjected to controlled air drying and finally oven drying. Various phases of soil shrinkage were described by Haines (1923) and Stirk (1954).Drying a fully saturated pedal soil results in an initial structural shrinkage (Stirk 1954) in which water loss is from large, stable pores and soil volume change is less than the volume of water removed. The second phase was termed "normal shrinkage" (Haines 1923) Fig. 1. The TDR lines facilitated the determination of the volumetric water content gradient in the core during drying, ensuring that the water content expressed for each tension was an equilibrated value for the core. The dv value's expressed, in this paper, for each core was determined by recording the net changes in the total mass ofthe core at specific intervals from saturation to oven dryness.The three-dimensional movement of points on the surface of the soil cores was measured by following the movement in the X-Y-Z directions of a set of pins which were placed in a grid pattern (Fig. 2)

The study of subsidence of organic soils requires measurements of changes in thickness of various layers in the deposit. This was achieved by drilling a bore hole to place magnetic targets at different levels. Using a fabricated detecting device, variations of thickness to 0.05 mm could be detected.