ASSOCIATED WITH LACAILLE IN HIS LABOURS. 101 



as orbits, instead of parabolas, or even mere straight 

 lines ; attraction confined them within its immense do- 

 main ; in short, these bodies ceased for ever to be liable 

 to superstition regarding them as prognostics. 



The stringency, the importance of these results, would 

 naturally increase in proportion as the resemblance be- 

 tween the announced orbit and the real orbit became 

 more evident. 



This was the motive that determined so many astron- 

 omers to calculate the orbit of the comet minutely, from 

 the observations made in 1759, throughout Europe. 

 Bailly was one of those zealous calculators. In the 

 present day, such a labour would scarcely deserve 

 special mention ; but we must remark that the methods 

 at the close of the eighteenth century were far from 

 being so perfect as those that are now in use, 'and that 

 they greatly depended on the personal ability of the in- 

 dividual who undertook them. 



Bailly resided in the Louvre. Being determined to 

 make the theory and practice of astronomy advance to- 

 gether, he had an observatory established from the year 

 1760, at one of the windows in the upper story of the 

 south gallery. Perhaps I may occasion surprise by giv- 

 ing the pompous name of Observatory to the space occu- 

 pied by a window, and the small number of instruments 

 that it could contain. I admit this feeling, provided it 

 be extended to the Royal Observatory of the epoch, to 

 the old imposing and severe mass of stone that attracts 

 the attention of the promenaders in the great walk of the 

 Luxembourg. There also, the astronomers were obliged 

 to stand in the hollow of the windows ; there also they 

 said, like Bailly : I cannot verify my quadrants either by 

 the horizon or by the zenith, for I can neither see the 



