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

Introduction xxi
Oriya. He found, however, a few Sanskrit
Siddhantas in the family library, and applied
himself diligently to master them with the help of
commentaries.
At the age of fifteen, when he came to learn
the meaning of lagna and the rules for calculating
ephemerides of planets, he was surprised to find
that neither did the stars apear on the horizon at
the right moment, nor could the planets be seen in
their right places. Again and again, he measured
with a graduated rod the relative distances of the
heavenly bodies in the vain hope of finding an
agreement between calculation and observation,
and, again and agian his hopes were dashed to the
ground. Was it possible that the rules and the
figures of the famous Siddhantas were not accurate
enough, or was it possible that he had made errors
in his daily observations? Correct observation was
the only test to settle the question. There were no
mathematical instrument-makers to supply him with
the requisite instruments. The old Siddhantas give
brief instructions for constructing them, and he had
no other alternative than to make for himself, a few
primitive instruments for measuring time and
angular distance.
Some of my readers may be desirous of
knowing something of his observatory. It was the
clear, blue vault of the heavens that was his
observatory; and its equipment consisted of an
armillary sphere and a vertical wheel as substitutes
for modern transit and alta-azimuth, and the
time-honoured clepsydra took the place of the
sidereal clock. Of course, the all-useful gnomon
found a place in the observatory, and I am
informed, he had also a self-revolving instrument