H. C. Lewis—Zodiacal Light. 439 
Numerous comparisons have been made between the bright- 
ness of the zodiacal cone and that of different parts of the Via 
acal cone. Although aware of the statements of some observ- 
ers as to their existence, the writer, during the whole of his 
observations, has never once been able to detect any certain 
pulsations, any movement, or any sudden change in brightness 
in any part of the zodiacal light; and he believes that all such 
changes in the eyesight of the observer. Since frequently an 
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