10 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 98 



occurred about the time of sunspot maximum and apparently moved 

 northward, at least as far as latitude 40°-50°. This condition is shown 

 by the third and fourth series of curves in figure 6. 



At the time of the less intense solar maximum of 1906 the maxima 

 of pressure were found in latitudes 40°-50° N. over the oceans as 

 shown in figure 5 and apparently moved from west to east, figure 7. 



Fig. 7. — Sunspot maximum of 1906 and atmospheric pressure. 



Hence, not only the positions of the areas of excess and defect of 

 pressure are determined by the intensity of solar activity, but also the 

 direction of the subsequent movement of these areas. The names 

 baroplions and baroinioiis have been suggested for these areas. 



A cosine series used in the way described above does not necessarily 

 give a period of its own length. If the monthly mean temperatures 

 at New York had been analyzed by a cosine series of 1 1 terms covering 

 11 months instead of 12, the resulting curve would have been exactly 

 the same as that shown in figure 2, except that the amplitude would 

 have been somewhat reduced. The same is true had the cosine series 

 contained 13 terms covering 13 months instead of 12. In each case 



