[ 34i ] 
M. Delalande’s method, it would fometimes, namely 
when at its maximum of 18", produce nearly 1 i. 
fecond of time. 
But, tho’ this demonftration may be admitted to be 
juft, yet it may perhaps be afked, wherein lay the fault 
of the method of computation here cenfured, and 
whether the time of the fun’s coming to the meri- 
dian is not regulated by his right afcenfion ? It may 
alfo be thought requisite, that the true manner of 
computing the equation of time, from the fun’s 
right afcenlion, fhould be fhewn. 
Firft, let ft be obferved, that when the pole is at 
P, A is the equinoctial point, and, when the pole 
is tranflated to Q, fome other point B is the equi- 
noctial point : therefore the fun’s mean right afcen- 
fion U P A is reckoned from A, and his apparent 
right afcenfion B QJ>, computed from his longitude, 
corrected by the equation of the equinoxes A B, or 
B S, is reckoned from another point B. Now the 
equation of time is proportional to the difference be- 
tween the fun’s mean and true right afcenfion, both 
reckoned from the fame point ; fo that if the fun’s 
mean right afcenfion is reckoned ffrom A, his apparent 
right afcenfion, in this cafe, fhould be reckoned from 
A too; or if the apparent right afcenfion is reckoned, 
more properly, from the apparent right equinox B, 
his mean right afcenfion, for this purpofe, fhould be 
reckoned from B likewife. For it is plain, from 
what has been faid above, that no fmall motion of 
the pole P can at all affeCt the abfolute time of a 
ftar in the equator’s coming to the meridian of any 
place ; for, the tangent Qj then becoming infinite, 
the angle P T Qj/anifhes ; therefore the mean equi- 
nox 
