Synopsis A new tool, much simpler than any previous type, for taking undisturbed samples of sand from below the water-table was introduced in 1948. Some investigations are described where its use has been important: (1) The crushing of a concrete sewer buried in sand. (2) Compaction from pile driving in a medium sand, resulting in a change of density from about 85 lb. per cubic foot to 101 lb. per cubic foot. (3) Measurement of the natural density of the Bracklesham sands. (4) The examination of laminated soils for ground-water lowering schemes. Continnous undisturbed samples have become an essential requirement when estimating the permeabili of laminated soils. The use of the sand sampler on about 15 investigations has proved it to be very satisfactory, and no modifications have been necessary. All types of sand except coarse sand have been sampled. Occasionally, the examination of samples has revealed distinctive grain structures indicative of the lack of disturbance from the sampling. The relationship between the measured and in-situ density appears satisfactory for medium and loose deposits, but there is an indication that the measured densities are lower than the in-situ for dense deposits. Numerous samples have been taken from depths down to 100 feet, and one from a depth of 130 feet. Une nouvelle machine-outil, et beaucoup moins compliquee que tout autre type anterieur, pour le prelevement des echantillons de sable intacts de dessous la nappe phreatique, fut introduite en 1948. Les resultats de quelques easais pour la realisation desquels l'emploi de cette outil a constitue une application importante, sont presentes: (1) l'crasement d'un dgout en beton enfonce dans la sable; (2) consolidation par suite de pilotage dans une sable moyenne, amenant a une variation de densite d'environ 85 livres par pied carre a 101 livres par pied ccarre; (3) la mesure de la densite propre des sables. de Bracklesham; (4) l'examen des sols laminaires pour des projets d'abaissement de la nappe phreatique. II faut des echantillons continns et intacts pour la determination de la permeabilite des sols laminaires. L'efficacite de l'chantilleur a sable s'est revelee comme satisfaisante pendant environ 15 essais, et aucunes modifications ne semblent necessaires. On a preleve des echantillons de toutes sortes de sable, sauf de la sable grossiere. De temps a autre, l'examen des echantillons a revele des structures de grain distinctives–ce qui indique qu'ils restent inacts apres l'chantillage. Le rapport entre la densite measuree et la densites sur place somble etre satisfaisant pour les couches measurees moyennes et molles, mais il apparait que les densites measurees sont plus faibles que les densites sur place pour des wuches epaisses. On a preleve dans une profondeur jusqu'a 100 pieds un grand nombre d'chautillons, dont un a une profondeur de 13 pieds.

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, had visited this great and imaginative project. He welcomed, therefore, the opportunity of congratulating the Authors and their firms and of thanking them for their great kindness on that extremely interesting visit, when it had been possible to see much of the work in hand.102. The problem of providing enough water for the fast-growing and bustling colony of Hong Kong was a difficult one and every available source had to be tapped.The project which the Authors described was a notable one by any standards. The idea of storing water in what had previously been an area of the sea, the dam itself, which was designed to allow considerable settlements, the huge purpose-built dredger and placer for building the main dam, the auxiliary works, including the neoprene weir (which had been inflated to show how it worked), the 30ft diameter tunnel between the dams and Tqi PO Tau, designed to carry water either way, the water treatment plant near Sha Tin, and the arrangements there to control the whole system when in operation, were splendid examples of what could be done by using the most modern engineering techniques.103. Speaking for the Secretary as well as for himself, he said that their best wishes went to the Authors and their firms for the successful completion of the project, which would be a major achievement in the engineering world.Mr N. A. F. Rowntree (Water Resources Board) said that barrages were a subject of discussion in Great Britain at that time and, since the responsibility for investigating the feasibility of two barrages had been placed on his Board, he was not only interested in the Paper but very pleased to see it presented at the Institution. The Plover Cove scheme had made it clear that works of this size could be carried out by British engineering firms, and the Water Resources Board had shown their confidence by asking British engineering consultants to look at the feasibility studies for which the Board were responsible. 105.Another important feature of the Paper from a public relations point of view was that it indicated the magnitude and complexity of the problems involved in carrying out this type of work. The rather light-hearted way in which requests for a barrage were sometimes made could be embarrassing, and he had been pleased to hear the procedure which had been adopted in Hong Kong. The foundations of the argument were the great need for water, the problem of providing storage for the adequate rainfall of the island, and the difficulty of finding a land location for this storage. To take advantage of the nature of the coastline and provide a barrage, had been a logical sequence of thought.106. After a great deal of consideration it had been decided that if a barrage

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