C 487 ] 
Jefuits themfelves, Ptolemy's Aftronomy was in great 
Vogue all over the Eaft s and they feem to fufpeft, 
that by this means the Chinefe might get fome faint 
Knowlege of it. It is certain, that from this time 
we meet with Things unknown to their former Ac- 
counts of Aftronomy . At this time, it is faid (c), 
Tchang-heng made a Catalogue of 2500 Stars. Such 
a Catalogue as thofe already mention’d were, we may 
fuppofe it to be, if it was at all 5 for Tchang-hengs 
Book is loft 5 and what Accounts we have of him or 
his Works, depend on the Authority of others. 
A.T). 284. (ft) liv'd Kiang-ki> the firft Chinefe 
that is faid to have known any thing of the Motion 
of the fix'd Stars. This we fee was 120 Years after 
the above-mention'd Arrival of the Jews in China 5 
but either they muft have been unskilful Relaters, or 
the Chinefe bad Difciples, fince Kiang-ki , it feems (e), 
made that Motion to be at the Rate of i° in 50 
Years 5 whereas ‘Ptolemy, it is well known, made it 
i° in 100 Years. It may be faid indeed, that this 
Difference fhews it could not be borrowad from Pto- 
lemy \ but then it fhews at the fame time, that it 
could not be the Refult of any Series of Observa- 
tions rand that is as much, I think, as we need be 
concerned about. And this will appear yet farther, 
by remarking, that A . ©. 460, it was made by 
Tfon-chong i° in 45 folar Years and 9 lunar Months (/). 
At other times it was made yet different ftili; but 
never, I think, from Obfervations of the Stars them- 
selves* 
(c) Obf. ut fup . Tom, 2. p, 25. (d) Ibid . p. 44* (t) Ibid , 
if) Ibid, p. 52, 
