MATHEMATIC AL PAPER > FR 
the meridian. This would be the apparent noon exadtly, 
if die fai snm alter: his de o tion 43 : But as’ this! is PART | 
po itko the bait ind afternoon eb eaten 
muft be applied to the tirhe of noon thus found, except at the 
pes when the, variation i is too EL. to A gd ny equation 
Ides Toup idk 
In Plate I. Fig. VI. let EPQL be the hour circle of p 
o'clock, and ECQ, a portion of the Eqnator. Let P. a the 
north-pole, L the fouth ; and PZL the meridian of fome 
place. Let the arc /Zt mark the latitude of a given place : : 
Then, "the ihe: poiat Z will be it's 's zenith ; andthe arc HOR v | il I 
ds A Te 
the dr mee mart the fum ree indien in e eiae ney 
time when his altitude is taken, and ava the declination in the 
afternoon,” when his altitude is the (ame as in the morning ob- - 
fervation.: Lét the angle ZP o- be the diftance of the fan dom 
eridian, at the sine; af, the emorning obfer i pep = the 
| nearly ; ; then fide PZ will be the co-latitude of nice se 
fide Po the fun’s co-declination, and the fide Zo the fun's co- * 
altitude or zenith. diftance. | Let: the co-altitude Zo bé fet off 
from Z tor, „a point in the arc Of the fan's d ön, at the 
i -obfervation, and through # dew the are 
Pr. > Let Zo lio E fet off from Z to S, a point in the arc 
of the finis declination, at the time of ‘the afternoon obíerva- 
m and through S draw the are PSL. Then, it will be evi- 
dent, 
