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showed maximum incidence at the height of the summer and this information was used as the basis for planning a mass oral vaccine campaign. A joint investigation was also conducted by Lederle Laboratories and the department into the feeding of oral trivalent vaccine to a large group of children; conversion rates in a sample of more than 60 of these were satisfactory, except in the case of three children.
During a cholera outbreak in the summer, research was con- ducted into various aspects of the carrier state with particular reference to the persistence of the organism.
Fisheries Research is the responsibility of the fisheries research station which is part of the Co-operative Development and Fisheries Department. This work is dealt with in detail in chapter 7.
Research and Applied Meteorology. Royal Observatory staff have only limited time for research and emphasis is therefore placed upon applied research in meteorology. During the year work started on the preparation of climatological summaries for aero- nautical purposes and when completed the summaries will aid air- lines in their long-term operational planning. A close network of raingauges has now been planned to study the distribution of rain- fall intensity within individual rainstorms and this investigation will help in the design of catchwaters and drainage systems. A study of the diurnal variation of rainfall over south-east Asia has been completed and brief studies on the mechanism of summer rainfall over Hong Kong were carried out during 1962.
Methods of forecasting the movements of tropical storms are still under investigation. A study of various objective techniques has begun and it is hoped that these will be suitable for operational forecasting. Work continued on the method which utilizes the pattern of upper-air flow at 700 millibars (about 10,000 feet) and it was applied to forecasting the movement of many tropical storms during 1962. The method compared very favourably with other available techniques. An investigation into the correlation between tropical storm positions, their intensities, and the associated micro- seisms has revealed that the continental shelf has a marked influence on the microseismic intensity.
The first results of radioactivity measurements carried out by the Royal Observatory were published as a scientific note and the