G70 



REPORTS OF ASTRONOMICAL OBSERVATORIES. 



to report, when relieved, whether they have seen any auroral light dur- 

 iugthe night ; and if not, whether the slcy has been sufficiently clear to 

 I)ermit any to be visible. These records for the past year are presented 

 in the following consolidated table — which, considering the difficulty of 

 distinguishing the fainter displays, is regarded as establisLing the trust- 

 worthy character of the record by the ge::eral accordance between the 

 three independent observers. It appears that out of 216 favorable 

 nights, 13 auroras were noted ; and if we may assume the same ratio to 

 apply to the clouded nights, about 22 auroral displays occurred during 

 the twelve months. 



Auroral disjiloifs in 1880. 



Name of month. 



Jannarv 



Febniary 



Man-li 



April 



May 



June 



July 



August 



September 



October 



November 



December 



Total for year 



Auroras. 



^ I 



0.0 

 0.0 

 1.3 



i.y 



0.3 

 0.0 

 1.0 



:!. 



1.0 

 2.0 

 3.0 



0.0 



Clear nights. 



^ I 



14.7 

 17.3 

 16.3 

 1«. 

 18.7 

 19.3 

 18.3 

 18.0 

 18.3 

 20.7 

 16.0 

 20.0 



223 i 213 |215.6 



Clouded nitrhts. 



in. 3 

 11.7 

 14.7 

 12 

 12.3 

 10.7 

 12.7 

 13.0 

 11.7 

 10.3 

 14.0 

 11.0 



155 143 1 153 I 150.4 



Summary of auroral records for eleven years. 



These observations were undertaken to throw light upon the stipposed 

 connection between the number of solar spots and the frequency of 

 auroras and of magnetic disturbances. They have now been continued 

 long enough to give interest to the foregoing summary compiled from 

 the general orders above cited. No corresponding record of solar spots 

 during this period of eleven years is at hand for precise comparison ; 

 .but such records have been preserved, and they show the number of 



