On each of
these instruments explanations of everything were given in Chinese
characters; and there were also engraved the 24 zodiacal constellations
which answer to our 12 signs, 2 to each.[11] There was, however, one error
common to all the instruments, viz. that, in all, the elevation of the
Pole was assumed to be 36 deg.. Now there can be no question about the fact
that the city of Nanking lies in lat. 32-1/4 deg.; whence it would seem
probable that these instruments were made for another locality, and had
been erected at Nanking, without reference to its position, by some one
ill versed in mathematical science.[12]

[Illustration: Observatory Terrace]

[Illustration: Observatory Instruments of the Jesuits.]

"Some years afterwards Father Matteo saw similar instruments at Peking, or
rather the same instruments, so exactly alike were they, insomuch that
they had unquestionably been made by the same artist. And indeed it is
known that they were cast at the period when the Tartars were dominant in
China; and we may without rashness conjecture that they were the work of
some foreigner acquainted with our studies. But it is time to have done
with these instruments."--(_Lib._ IV. _cap._ 5.)

In this interesting description it will be seen that the Armillary Sphere
[B] agrees entirely with that represented in illustration facing p. 450.
And the second of his photographs in my possession, but not, I believe,
yet published, answers _perfectly_ to the curious description of the 4th
instrument [D]. Indeed, I should scarcely have been able to translate that
description intelligibly but for the aid of the photograph before me. It
shows the three _astrolabes_ or graduated circles with travelling indexes
arranged exactly as described, and pivoted on a complex frame of bronze;
(1) circle in the plane of the equator for measuring right ascensions; (2)
circle with its axis vertical to the plane of the last, for measuring
declinations: (3) circle with vertical axis, for zenith distances? The
Gnomon [A] was seen by Mr. Wylie in one of the lower rooms of the
Observatory (see below). Of the Globe we do not now hear; and that
mentioned by Lecomte among the ancient instruments was inferior to what
Ricci describes at Peking.

I now transcribe Mr. Wylie's translation of an extract from a Popular
Description of Peking:

"The observatory is on an elevated stage on the city wall, in the
south-east corner of the (Tartar) city, and was buil