(4)
Great Quadrant, of 6 feet radius. (5) Sextant of about 8 feet radius. (6)
Celestial Globe of 6 feet diameter.
As Lecomte gives no details of the old instruments which he saw through a
grating, and as the description of this zodiacal sphere (No. 1)
corresponds in some of its main features with that represented in the
photograph, I could not but recognize the possibility that this
instrument of Verbiest's had for some reason or other been removed from
the Terrace, and that the photograph might therefore possibly not be a
representation of one of the ancient instruments displaced by him.[3]
The question having been raised it was very desirable to settle it, and I
applied to Mr. Wylie for information, as I had received the photographs
from him, and knew that he had been Mr. Thomson's companion and helper in
the matter.
"Let me assure you," he writes (21st August, 1874), "the Jesuits had
nothing to do with the manufacture of the so-called Mongol instruments;
and whoever made them, they were certainly on the Peking Observatory
before Loyola was born. They are not made for the astronomical system
introduced by the Jesuits, but are altogether conformable to the system
introduced by Kublai's astronomer Ko Show-king.... I will mention one
thing which is quite decisive as to the Jesuits. The circle is divided
into 365-1/4 degrees, each degree into 100 minutes, and each minute into
100 seconds.
