सिद्धान्तदर्पण (महामहोपाध्याय सामन्त चन्द्रशेखर सिंह - नग्न-नेत्र खगोल वेध एवं गणित महाकोश)

Introduction lv
by Dr. Thibaut), makes no sensible difference in the
result. Be the explanation what it may, it is to be
observed that Chandrasekhara gives 22°-26' as the
observed ayanamsa, which is 15' greater than what
we have assumed. This fact shows that somehow
or other, the length of the year in use was slightly
less than what we find it in the modern
Surya-Siddhanta.
At any rate, the vernal equinox in Revati did
not mark the beginning of the existing zodiac.
Ranganatha, a commentator of Surya-Siddhanta,
supports us by saying that the equinox fell
somewhere near Revati. For, the equinox fell on the
star in Saka 498, and during the period since
elapsed, the Sun has moved through an excess of
3°-5'-29", thus making the ayanamsa 21°-29'-18".
Even the Siddhanta's position of the star leaves a
difference of half a degree. So we must suppose
that the star Revati was nearly a degree to the East
of the initial point when the zodiac happened to
commence its existing fixity.
If any use is to be made of the recorded Dhruvas
of the stars, it appears to me to be the most
reasonable course to select those stars which are
situated near the ecliptic. For, as has been already
pointed out, the errors of observation by means of
rude appliances will increase with star-latitudes.
Accordingly, the following twelve stars situated
within five degrees on either side of the ecliptic are
given below for composition.