72 ASTRONOMICAE AND 
dent, that when the fun has the fame zenith diítance in the af- 
ternoon: obfervation that he had in the forenoon, he will be 
further diftant from: the meridian by the fpace pg, meaíured 
upon the Equator, equal to the angle pPg. — Biíe& the angle 
GPS, and draw the pricked arc PL, (the fame as adding the 
half. interval to the time of the forenoon obfervation) which 
fhews the mean noon; but it is as much after the apparent 
noon, or the true time of the fun’s pafling the meridian, as 
the {pace Cå upon the Equator, which is equal to half 7. 
"The time anfwering to Cå, therefore, muft, in this cafe, be 
fubtracted. from ` the mean noon, which will reduce it to the . 
meridian PCL, or, which is the fame thing, give the true time 
when the fun a the meridian, by the clock. This equa- 
tion, Cå, may eafily be found —€— by the trian- 
' gles PoZ and PSZ. 
EXAMPLE. Bugi x 
dmg 1 Cambridge, latitude 42° oyag. N. fuppofe the me 
of the fun. taken April 2, 1783, at 8 yo’, A. M. i.e. atg 
20', or 50°, from the meridian, and the correfponding altitude 
taken in the afternoon ; required the equation to the Cornel 
Oeming sidnades bu 
April 2,1 " a or,A.M: E 
tie 7 "SEIT devo 1^oo"Cem. het: 59! ot 
At 3% ARX t M. fitt, E 7 22 Com.==PS 84 52 48 
-latitude, | Y jar mc — S 36 32. 
fog 220 = ss a D Pie modom $o EO S 
: it 
Oe nights dissi. a -a 
