A brief note on this subject was published in the GeologicalMagazine, Vol. LXXII, October, 1935. In September of that year certain more detailed experiments were prepared, whose object was to afford a means of measuring the rate of accretion of tidal silt on different types of marsh in various parts of the island complex. Reference to Text-fig. 1 will show that five lines were prepared. In each case patches of fine and distinctive light brown Lower Greensand were spread over the marsh at measured intervals. Sometimes the patches, each about 2–3 feet in diameter, were put down at regular distances, but, on account of the number of small creeks and salt pans intersected by any straight line across a marsh, it. was usually more convenient to make the intervals between patches irregular. The sand was spread as a fine layer in and on the vegetation, and after it had been covered by one or two big tides, it settled down easily on the true marsh surface under the plant covering. It was then only a matter of time before it was covered by tidal silt. The sand was put down in September, 1935, and the measurements of accretion were made at the end of June, 1937.