350 ON THE INDIAN, Sec. 



solstitial col Lire ; a third turning on the poles of the 

 ccliptick and serving to mark longitudes ; and a fourth, 

 within the other three, furnished with sights to observe 

 celestial objects and measure their latitudes and longi- 

 tudes*. 



Whether the ancient Greeks had any more com- 

 plicated instrument formed on similar principles, and 

 applicable to astronomical observations, is perhaps un- 

 certain. We have no detailed description of the instru- 

 ment, which Archimedes is said to have devised to 

 represent the phenomena and motions of the heavenly 

 bodies; nor any suf^cient hint of its CQUstruction-f- ; 

 nor does Cicei^o's account of the sphere exhibited by 

 PosiDONius X suggest a distinct notion of its structure 



Among the Arabs, no addition is at present known 

 to have been made to the Armillary sphere, between the 

 period when the Almagest was translated ^, and the 

 time of AivHAZEN, who wrote a treatise of optics, in 



♦ Lalande Astron. I, 13. {§ 2270). 



•f If Claudian's epign^m on the subject of it was fovinded upon 

 any authority, the instrument must haye beep a sort of orrery, en-f 

 closed in glass. 



Vide Claud, epig. Cicero. Tusc. Quaes. I. J Nat. Deo. 2. 35. 



% Cic. Nat. Dfo. 2. 34. 



§ in the Htjira year 212, or A. D. 82", by Ax«[azen ekn Yuskf 

 with the aid o. Se'RG}us (Mpntuci^a, 2' P- 30-A) ; or rather by 

 isHAi; BEN HoNKN, whose death is placed about the Htjira year 2C0 

 (I^J'Herbelot, p. ■'.sK). Afcoiding to the Cuiliful'i^un, Ishak's 

 version was epitomised by Hajai bkn Yusef^ by 'J'habit bek 

 JVARRAH, and by N AsuiUDDiN lusi. Oiher versions, however, 

 are nientioDcd : paiticijlarly, one by IIajab, said to have been cor- 

 rected first by Hi/NKN BKN Isn.iK, and afterwards by Thabjt; ano- 

 fher by Thabjt himself ^ and a third by Muhj uen vaihyah. A 

 dtft'erent accf unt is likewise give.'i of the earliest translation of the 

 Almagest, which is ascribed to Abu Hisan and Salmaw, who are 

 jajicj to haye completed it, after the I'ailure of otbe. learned men, 

 Who had preyjyusly auempcvd the jraniil^iop, Mention ie aUo 



