96 Mr. aueert’s Method of 
horary arc obferved by the middle wire not turning out 
exactly according to the computation, is of no confe- 
quence to the obfervations. Some little difference may 
arife in it from fmall inaccuracies in the eftimation of the 
ftar’s apparent polar diftance, the latitude of the place, 
or the error of the line of collimation ; or from not letting 
the telelcope exadi ly to the proper zenith diftance ; but 
as the chief intention of the computation is to find the 
vertical circles in which the ftar hath no motion in azi- 
muth, the other parts of it need not be ftridtly attended 
to. 
The following manner of inferring mean time from 
the ftar’s meridian paflage being more convenient and 
concife than the ufual one, may alfo be acceptable. 
From the ftar’s apparent right afcenfion, increafed by 
24 hours if neceftary, fubtradl the Sun’s apparent right 
afcenfion for apparent noon; diminifh the remainder by 
the proportional part of the ftar’s acceleration, at the rate 
of 3' 5 5", 9 1 for 24 hours, of which a table is eafily com- 
puted ; to this laft remainder apply the equation of time 
for apparent noon, according as it is additive or fub- 
tradlive; the refult will be the mean time of the ftar’s 
palling the meridian. 
E X A M P L E. 
