28o 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 70 



factor found by us is considerably greater than those found for the 

 correlation between the " solar constant " and the temperature at 

 the various stations examined by Dr. Clayton. 



We have also computed the seven-day means of the mean daily 

 temperature at Bergen (taken with the thermograph). In figure 

 99 we have plotted the consecutive seven-day means of the " solar 

 constant" as obtained at Mount Wilson (curve S) of the daily 

 pressure difference between Christiania and Bergen (curve B) and 

 of the mean daily temperature at Bergen (curve T), for the period 

 from June to September, 191 5. 



JUNE I JULV I AUGUST | SEPT. 



Figure 99. Curves giving tlie 7-day means in June to September, 1915. 

 cf : 5" the " solar constant " ; B the pressure gradient between Bergen and 

 Christiania ; T the temperature at Bergen ; V the variation of pressure from 

 day to day at Bergen. The small letters along the curves indicate correspond- 

 ing maxima and minima. 



The agreement between these curves is very good. The maxima 

 and minima of the pressure difference (marked by letters a-n) fol- 

 low mostly some days after the corresponding maxima and minima 

 of the "solar constant" (marked by the same letters), while the 

 corresponding maxima and minima of the daily temperature follow 

 as a rule still a little later. 



As it might give an indication of the variability of the meteor- 

 ological conditions we have taken the difference in pressure from 

 day to day (at 8 a. m.) at Bergen, and have plotted the seven-day 



