MATHEMATICAL PAPERS 9 
the fame time I obferved the diurnal alterations in the dipping 
neédle, "Theíe obfervations are too: numerous to .be inferted 
here. In general, there is a remarkable regularity in the ob- 
fervations taken by the variation needle. The variation gene- 
rally increafes from feven or eight o'clock, A. M. till about 
two or three, P. M. From this time it generally decreafes 
until feven or eight the next morning. The inclination or dip 
is fübje& to rather greater diurnal alterations than the variation ; 
‘but they do not feem to be fo regular in their changes. “The 
‘Jeaft inclination I have ever obferyed was 68° 21' ; the greateft 
79.56". 
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E riu. CNN 
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