§ Mr. J. Johnsonasked the Secretary of State for the Colonies if he will make a statement regarding the rain-making experiments of the East African Meteorological Department, Tabora, Tanganyika; and whether any conclusions can yet be formed.
§ Mr. Lennox-BoydTabora, which is a railway junction and administrative centre in the Western Province of Tanganyika, is dependent on the Kazima Dam for its water supply. Because of the partial failure of the seasonal rains, the level of the reservoir was dangerously low at the end of March and it was therefore decided to try out a "cloud-seeding" technique which had been evolved by the East African Meteorological Department in conjunction with the Admiralty and the Ministry of Supply. This technique involves the use of 2-inch naval rockets, modified to incorporate particles of sea salt. After the necessary safety precautions had been taken, the experiments were carried out from the 12th April to the 2nd May and 37 rockets were fired during this period. Under the conditions prevailing the best results were achieved when the rockets burst at about 3,000 feet and about 1½ miles downwind of the catchment area of the Kazima Dam.
The results are still being studied, but there is definite evidence that under suitable conditions cloud-seeding does produce rain. A significant feature of the experiments was the repeated occurrence of rain over the catchment area some 12 minutes after seeding. At the conclusion 25W of the experiments the level of the reservoir was 2½ inches above the level at the beginning of the experiments, despite a daily consumption of 250,000 gallons and a high loss through evaporation. Rainfall recorded in the catchment area during April was about 1 to 1½ inches more than that measured at stations near to but outside the catchment area.