268 



BELL SYSTEM TECHNICAL JOURNAL 



5 KILOMETERS 



CONTOUR INTERVAL 20 FEET 

 DATUM IS MEAN SEA LEVEL 



Fig. 11 — Field strength contour map of Boston, Mass. Receiver located on S^eaverns Street ne.i 

 Center Street as shown by the solid circle. Frequency = 34.6 mc. Field strength in decibels abov 

 one microvolt per meter. 



