10. 



THE KELATIVE POSITION OF THE TWO HEADS OF BIELA'S COMET. 



[Communicated to the Royal Astronomical Society (March 14, 1846).] 



THE diagram shows the relative position of the two heads of Biela's 

 Comet on Jan. 26'5, Feb. 11 '5 and Feb. 27'5 mean Greenwich time, 

 projected on a plane parallel to the equator. The rectangular coordinates of 

 the smaller head, referred to the larger as origin, are as follows 



The unit of measure is a line subtending an angle of 1" at the mean 

 distance of the Earth from the Sun ; the plane parallel to the equator is the 

 plane of xy ; and the axis of x is a line drawn in the direction of the 

 first point of Aries. 



