Cable Problems: The cable for the well logging instrument 
may be strong enough for a depth of 2000 feet in a well but it may 
not be adaptable to 20,000 feet of depth in the sea. The Woods Hole 
group has not been able to persuade a cable manufacturer to build a 
cable with an electrical lead in it that can be guaranteed to be safe 
to lower more than 20 or 30 times. In oceanographic work the cable 
goes down under terrific tensions and when it comes back up the lead 
tends to creep inside the cable. Eventually the cable breaks the lead. 
The cable used in the oil industry (well logging) just will not work 
at sea because the ship heaves on it; the winch moves up and down 
quite rapidly as the ship rolls and pitches in the seas. The strains 
are much higher than those faced in the oil industry. 
By-Passing Cable-Conductor Problem: If it is necessary to have 
the electric circuit at the bottom it may be possible to send the power 
down with the instruments. Then only a regular cable would be needed 
to lower and raise the measuring devices. The inclusion of a recordirg 
depth element would provide the essential depth el as Similar 
instruments have been used to measure radioactive elements in the 
atmosphere. The instruments are sent up in baloons and telemeter 
their information back to the surface; perhaps the same set up can 
be used either with a telemeter circuit or with a recorder a Sd 
Mid-Depth Experiments: Many of the deep water experiment 
problems may be eliminated by working in shallower water, i.e. in or 
below the eee The evidence shows the quietest waters 
are at mid depths, not at the bottom. At mid depths the experiment 
is likely to run for the longest time. To get the radioactive material 
(16) 
to these depths may be a problem. However, mixing may be rapid 
-69- 
