6.8 SrFALLOUT COLLECTIONS ON WEATHER SHIPS The relative fallout on the open ocean compared to that on the land has not been definitely measured. Most of the suitable island sampling locations are of sufficient size to cause changes in the micrometeorology and to give results that may perhaps be different from that on the ocean surface itself. The U. S. Weather Bureau, through Dr. Lester Machta of the Special Projects Branch, has begun collections on the stationary weather ships in the Atlantic and will begin collections in the Pacific. These ships are on station for approximately six weeks, and open pot type collections are made during this period. The actual collection units are those developed by the Air Force Cambridge Research Center and loaned to the Weather Bureau for this work. The data are not available for a long enough period to give reliable comparison with shore stations; however, the available results are tabulated in Table 67. 138 .