DIVISIONS OP THE ZOD'tACK, SsS 



place is its horizon. He concludes by showing, that the 

 instrument maybe made to revolve with regularity, by 

 means of a current water ; and hints, that the appear- 

 ance of spontaneous motion may be given, by a con- 

 cealed mechanism, for which quicksilver is to be em- 

 ployed. The manner of using this instrument for 

 astronomical observations ha? been already explainecj 

 (p. 326). 



More ample instructions for framing an armillary 

 sphere are delivered in the Sidd'^hania siromani. The 

 passage is too long for insertion in this place ; and I 

 reserve it for a separate article, on account of the ex- 

 planations which it requires, and because it leads to. 

 the considerations of other topicks *, which cannot be 

 sufficiently discussed in the present essay. A brief ab- 

 stract of Bha'scara's description may here suffice. 

 In the center he places a small globe to represent the 

 earth encompassed with circles for the orbits of the 

 planets arranged like the curved lines in a spider's 

 web. On an axis passing through the poles of the. 

 earth, and prolonged on both sides, a sphere, or as- 

 semblage of circles, is suspended, by means of rings or 

 tubes adapted to the axis, so that the sphere may move 

 freely on it. This assemblage of circles comprises a 

 horizon and equator adjusted for the place, with a 

 prime vertical meridian, and two intermediate verticals 

 (intersecting the horizon at the N. E. and S. W. and 

 N. W. and S. E points) ; as also the equinoctial colure. 



• Among others, that of the precession of the equinoxes ; re- 

 specting which different opinions are stated by Bhascara. It ap- 

 pears from what is said by him, that the notion of a libration of 

 the equinoxes has not universally prevailed among H.ii}du astrono- 

 mers. The conecter opinion of a revolution of the equinoctial 

 points was a.dvanced by some authors, but has not obtained th* 

 general sufF age of Hindu writers on astronomy. 



Vol. IX. 2 A. ' 



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