NO. y BRIGHTNESS OF LUNAR ECLIPSES — FISHER 45 



It is found that the position of the moon's path with regard to 

 the center of the shadow is significant ; when the moon passes clear 

 of the center on the south side, the shadow is brighter; when it 

 passes over the center, less bright ; when it clears the center on the 

 north side, decidedly dim, on the average. This is shown not only 

 for all 68 eclipses, but also for 13 pairs of consecutive echpses. 



In 37 total eclipses there seems to be no very decided effect of 

 distance ; on the average, the shadow at middle distances is perhaps 

 somewhat brighter than at perigee or apogee. 



In 37 total eclipses there is a marked effect of the seasons, which 

 are implied in the longitude of the shadow ; winter eclipses have 

 been bright, spring eclipses dim, summer and autumn eclipses inter- 

 mediate and not very different, on the average. 



The eft'ect of volcanic dust haze in the 3 great atmospheric dis- 

 turbances named for Krakatoa, Pelee and Katmai has shown itself 

 in the average dimness of 10 included eclipses, as compared with 

 42 eclipses, 1880-1922, not in the disturbed periods. 



If all the southern eclipses occurring in the disturbed periods 

 were removed, the discrepancy between the brightness of the eclipses 

 in the disturbed periods and of those outside them would be increased. 

 It is as if the northern part of the shadow were specially affected by 

 these disturbances, and were in general darker than the southern 

 part. 



The average difference between winter and spring total eclipses 

 is perhaps increased by the absence of winter eclipses during the dis- 

 turbed periods. 



During the period discussed there is no discernible relation between 

 the solar cycle and the brightness of lunar eclipses. And, given the 

 effects of north latitudes and volcanic dust hazes as proved, and 

 acknowledging ignorance as to the magnitude, or even the occurrence, 

 of suitably great volcanic eruptions, it is doubtful whether an effect 

 of solar activity can ever be disentangled from dust effects, in records 

 prior to 1880, all the more as the earlier records show greater gaps 

 and fewer detailed statements. 



It is to be hoped that in the future eclipses of the moon may be 

 studied with more respect, by astronomers and meteorologists, profes- 

 sional and amateur; and especially, in western North America, in 

 South America, in the Hawaiian Islands, Japan, the Philippines, East 

 Indies, Australia, New Zealand, the islands of the South Sea, and 

 even the Arctic and Antarctic ; and that results may be published in 

 accessible scientific periodicals, without biassed and destructive edit- 

 ing. Anybody with good eyesight and a watch can make valuable 



