The Working Group on the Measurement of Precipitation met at the headquarters of the Swiss meteorological service on July 29 and 30, 1955, under the chairmanship of Mr. L. Poncelet (Belgium) mainly to revise a World Meteorological Organization (WMO) publication on international meteorological instruments and observing practice with particular attention being given to revising the sections dealing with precipitation observations at sea and in mountainous regions. The group, after discussing the need for an international reference precipitation gauge, decided that while it was not possible at the time to specify die detailed design of such an instrument, an interim working model should be introduced as soon as possible. The Working Group on Radiosonde Comparison of the WMO Commission for Instruments and Methods of Observation met in Payerne, Switzerland from November 14 to 18, 1955, to make preparations for the second world comparison of radiosondes scheduled to begin on May 23, 1956 in Payerne. A number of technical and financial questions were dealt with in detail during the session.