to go down to the trade wind regions where there is a steady wind 
and more or less constant conditions throughout the year. 
In the winter in open ocean the water is actively overturning 
down to about 200 meters. In the summer on a typical day it over- 
turns down to about 25 feet, almost a whole order of magnitude 
(16) 
difference. 
Instrumentation for Backgrounds. 
Instrumentation is a problem in any of those ocean experiments, 
Instead of thinking of instruments for a tracer experiment, it may 
clarify things to think of instruments necessary to determine the 
natural radioactivity in the sea. If instruments were developed for 
backgrounds, then they would be available for the other met tele 
If instruments were available they could be put aboard any ship 
going out and could take background measurements as part of the othez 
ae Among all the oceanographic laboratories there are ships 
going generally in all directions. If 4 or 5 instruments were availabic, 
it would be possible to essentially cover all of the world's ocean 
areas and all types of een 
Work of Lamont Institute: To establish natural backgrounds 
for several types of radiations as a function of depth in the sea, 
the Lamont Institute group decided it would be easiest to utilize 
photographic plates loaded several different ways. The plates are 
fine to establish natural backgrounds, but they are not worth much as 
an instrument in the diffusion experiments because they would not 
give the information fast enough. 
Tih 
