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BELL SYSTEM TECHNICAL JOURNAL 



indicated by the thermomilliammeter. So long as these were dupli- 

 cated at both ends of the path, it was possible to determine the relative 

 values of fields at the two ends, regardless of absolute errors. Investi- 

 gation of the behavior of the meter and of the method in general, 

 indicate that the absolute error itself is not large. 



The map of Fig. 2 shows the locations of the transmitting and 

 receiving sites used. The tests may be divided into two groups. 

 Propagation over water was studied mainly with the transmitter 



Fig. 2 — Transmitting and receiving locations. 



located on the bluff at Cliffwood Beach. Measurements on trans- 

 mission over land were made from the transmitter at Deal. Lines 

 radiating from these two points indicate the various transmission 

 paths studied. 



Transmission Over Sea Water 



For the measurements on propagation over water at 34, 51 and 

 80 mc, the receiving antenna was located at the water's edge, except 

 for a few special tests. The height of its midpoint was varied up to a 

 maximum of about twelve meters above sea level. The data presented 

 in Fig. 3 show the results with the maximum elevations and vertical 

 polarization (vertical electric field). 



This figure shows that the received field was below the inverse 



