o 
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71 ' 
Dll C. CHK.KID 
AXALYSIS OF RESULTS FROM 
THE KEW .MAC4XI-:T0(4RAPHS 
Tlie principal niaxhnnm is fcmnd in tlie afternoon ; the time varies from 4 to / PAi., 
and, as Avith the minimmn, is earlier in Avinter than in summer (see hg. 5). 
NormalH^ there AAmnld seem to he 2 maxima and minima, the second maximum and 
minimnm occurring in the earh" morning AAuthin a feAA’ liours of one another. This is 
slioAAoi, tliough fainthi eAx^n in the mean inequality for the year. In tlie Avinter 
months, lioAvever, the values in the earlier morning hours hecome so nearly stationary 
tliat the true nature of the phenomena is uncertain. 
'flie ramies and the sum of the 24 hourly differences from the mean both shoAS* tAvo 
maxima in summer, in May and July, the intervening minimum being more clearly 
marked than in the other elements. The AAunter minimum in December, on the other 
hand, is someAvhat less clearh^ marked than in H or I. 
Northerly (And Westerly Components. 
§ 20. All the months included in Table XY. shoAv 2 maxima and minima in the 
diurnal inequality of N, and the same is true of the mean inequality for the year 
{ef. fig. 6). As Avith H, the most conspicuous turning point is the forenoon minimum ; 
Init its time of occurrence is an hour or so later than in H, A'arying from 11 a.m. to 
noon. In December and March the forenoon maximum is the larger; but in June, 
and in the mean inequalitA' for the Amar, the afternoon maximum—occurring usually 
at 7 or 8 P.AI. —is decidedly the larger of tlie tAvo. The early morning minimum, 
though not Amiy cons])icuous, seems to haA'e a A^ery uniform time of occurrence. 
The phenomena met Avith in the case of AY (Table XA I., fig. 6) naturally resemble 
tliose met AA'ith in D. The maximum at 1 or 2 p.ai., and the minimum at 8 or 9 A.M., 
are someAvhat later than the corresponding turning points in the declination. In 
June there is no trace of a second maximum and minimum, and in the mean inequality 
for tlie A’ear tlieir presence is at least doulitful. In Decemlier the eA’ening minimum 
is the more jirominent of the tAA’o. 
Toted Force. 
§ 27. Tlie diurnal inequality of T (see Table XA'IL, figs. 6 and 7) sIioaaas 2 maxima 
and minima, of AA’hich the afternoon maximum at G or 7 p.m. and the forenoon 
minimum at about 1 1 a.ai. are the most important. The eaily morning maximum 
and minimum occur pretty close together, and their difierence is generally small. 
'Idle T inequality' cui’A^es appear exceptionally regular, Avhich is hardly Avhat one 
AA'ould haA’e expected, considering that A’ariations in both H and A are iiiA’oh'ed. 
From a mathematical standpoint, T is most naturally regarded as the resultant of 
AA^, N, and A", and so mean inequalities for the year for these elements are shoAvn 
alongside of the corresponding inequality for T in fig. 6. 
It Avill lie ohserA’ed in Tallies XL to XA"II. that the range and the sum of the 24 
CO 
difterences in March generally resenilile closely the corresponding quantities from the 
