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FOREWORD 
An important function performed by the U. S. Naval Oceanographic 
Office is the periodic publication of the H. O. 1706 World Magnetic Varia- 
tion Chart. The recent edition of this chart was, for the first time, compiled 
from a mathematical model of the geomagnetic field. This report presents the 
results of an evaluation of the chart's reliability and provides insight into the 
challenging task its construction poses. 
vA = kig Caps : 
L. E. DECAMP 
Captain, U. S. Navy 
Commander 
U.S. Naval Oceanographic Office 
0 0301 004659183 8 
