80 Prof. W. A. Norton on Donati’s Comet. 
two eee with regard to the forces of repulsion thus de- 
veloped; that the force exerted by either body was of the same 
ie: which of the two suppositions is the most probable. 
he latter is certainly no less so than the former. If we adopt 
eceding or convex side of : 
have made the calculations, regarding the solar repulsion 8 _ 
var. between certain prescribed limits. The determinations 
of the breadth of the tail, at various points of its length, accor 
with the results of observation; at the same time that the tail 8 
found to have the form and positions actually observed : 
The ‘supernumerary tails observed were but lines of receding 
