Influence of the Moon on Declination of the Magnetic Needle. 101 
magnetic interval for the Philadelphia station. At Toronto the 
intervals are not so regular. e secondary range exists there, 
] 
to March). For the summer season we have 11087 observations, 
and for the winter 10557. 
In the complete memoir the tables of the hourly sums of the 
lunar variations for the summer and winter seasons are given, 
and the tabular results are expressed-analytically. The curves 
representing them are shown in the annexed Diagram C. 
The characteristic feature of the annual inequality in the lunar 
diurnal variation is, therefore, a much smaller amplitude in win- 
ter than in summer. Kreil indeed inferred from the ten year 
irregularity consists in the earlier occurrence of the maxima and 
minima in winter than in summer. The winter curve precedes 
the annua curve) about six hours after the lower culmination. © 
Th the winter season this last mentioned maximum east deflection oe 
1s actually the smaller of the two. We have co 
- = 85'-4, secondary 31’ 
= 25 = i eo Be. : 
difeidies = sa oe IO 8, be i 
Maximum summer range, 
winter “ - 
At Prague the maximum summer range was 44”, — 
I next proceed to examine whether the phases, declinat a3 
parallax of the moon, have any sensible effect upon the 
magnetic declination. Dr. Kreil found from a ten years series 
es isk 
