Dreyer — Oil InstrumenU in the Old Observatory, Peldng. 471 



diameter. It is added, that tlie motions of the stars were referred to 

 the Equator, and that there was no instrument in use for observing 

 the motion on the ecliptic. This would seem to indicate, that the 

 Chinese astronomers, who in so many respects were behind the 

 Greeks in their knowledge, had actually invented equatoreal armillse 

 (which were not in use in Europe before Tycho Brahe), and used 

 them instead of the less convenient and unsymmetrical " armilljB 

 zodiacales," invented by Hipparchus, and still used even by Walther 

 and Hegiomontanus. 



But even if it be admitted that the description of these old instru- 

 ments is much too vague to found on it a claim for the Chinese 

 astronomers of the time before Christ as being the inventors of the 

 equatoreal armiUte, at any rate it is now certain that Ko Show-King, 

 the astronomer of Koblai Khan, constructed such armillse three 

 hundred years before Tycho Brahe. It has been suspected by the 

 younger Sedillot^ that Alhazen knew equatoreal armillte ; but even if 

 this was really the case, it would probably be carrying conjecture 

 too far to suppose the Mongol astronomer to have heard of this 

 occidental invention. 



The instruments of Ko Show-King were examined in one of the 

 first years of the seventeenth century by the Jesuit Matteo Kicci 

 (who died in China in 1610),^° who speaks of them as being counter- 

 parts of some he had seen at [Nanking, and described at some length. 

 Mr. Wylie (/. c. p. 18) quotes the following part of this description 

 from Colonel Yule's translation in The Boole of Ser Marco Polo 

 (Vol. ii.): — "A second instrument was a great sphere, not less in 

 diameter than that measure of the outstretched arms which is 

 commonly called a geometric pace. It had a horizon and poles ; 

 instead of circles, it was provided with certain double hoops, the void 

 space between the pair serving the purpose of the circles of our 

 spheres. All these were divided into 365 degrees and some odd 

 minutes.'^ There was no globe to represent the earth in the centre,- 

 but there was a certain tube, bored like a gun-barrel, which could 

 readily be turned about, and fixed to any azimuth, or any altitude, so as 

 to observe any particular star through the tube, just as we do with 

 our vane-sights." 



This description evidently refers to an imitation of the equatoreal 

 armillee now in the courtyard of the Peking Observatory. The photo- 

 graph shows in fact very distinctly that all the circles are double, 

 separated by a narrow inteiwal. Whether this interval was intended 

 for the hollow tube to slide in, or whether the circles were only made 

 double in order to strengthen the instrument, it is not easy to see. 

 Perhaps both these objects were kept in view. The tube appears to 

 have four longitudinal slits in it, 9,0° apart, and interrupted near the 



^ ProUf/omencs dcs Tables Astronomiqucs cV Olouf/h- Beg. Paris, 1847, p. cxxxiv. 



^" JiJcher's Gelehrtcn-Lcxivon, Vol. iii. 



" It will be remembered that the Chinese divided the circle into SGSt". 



