440 
It will be seen from this Table that the calculated range 
has two maxima and two minima in the month, the maxima 
occurring one or two days after syzigies, and the minima one 
or two days after quadratures. This result agrees very closely 
‘with that deduced from a direct examination of the mean 
ranges, as given in the former communication. 
The morning range varies within wider limits than the 
evening one, the extreme variation of the former being 1°85, 
and that of the latter 1°60; their mean variations are 1°60 
and 120 respectively. This difference is due to the circum- 
stance that the interval between the epochs of greatest and 
least declination in the former case is six hours, which is also 
the interval between the maxima and minima of the lunar 
change ; and consequently the lunar variation is doubled in 
its effect upon the range. In the case of the evening range, 
on the other hand, the interval of greatest and least declina- 
tion is nine hours, and they cannot, therefore, both coincide 
with the extremes of the lunar variation. 
