479 



TABLE 505.— SECULAR CHANGE OF HORIZONTAL INTENSITY, UNITED STATES 



Smoothed values of horizontal intensity in cgs units at the indicated places for January 1 of 

 the years stated. The remarks about smoothing, in Table 502, apply to this table as well. 



TABLE 506.— VERTICAL MAGNETIC INTENSITY, UNITED STATES 



This table gives for the epoch January 1, 1950, the smoothed vertical intensity, Z, expressed 

 in cgs units, corresponding to the longitudes west of Greenwich in the heading and the north 

 latitudes in the first column. The remarks about smoothing, in Table 502, apply to this table as 

 well. 



SMITHSONIAN PHYSICAL TABLES 



