Le Verrier attained so much fame by this discovery, that when, in 1854, Arago’s place had to be filled at the head of the great Paris Observatory, it was universally felt that the discoverer of Neptune was the suitable man to assume the office which corresponds in France to that of the Astronomer Royal in England.  It was true that the work of the astronomical mathematician had hitherto been of an abstract character.  His discoveries had been made at his desk and not in the observatory, and he had no practical acquaintance with the use of astronomical instruments.  However, he threw himself into the technical duties of the observatory with vigour and determination.  He endeavoured to inspire the officers of the establishment with enthusiasm for that systematic work which is so necessary for the accomplishment of useful astronomical research.  It must, however, be admitted that Le Verrier was not gifted with those natural qualities which would make him adapted for the successful administration of such an establishment.  Unfortunately disputes arose between the Director and his staff.  At last the difficulties of the situation became so great that the only possible solution was to supersede Le Verrier, and he was accordingly obliged to retire.  He was succeeded in his high office by another eminent mathematician, M. Delaunay, only less distinguished than Le Verrier himself.

Relieved of his official duties, Le Verrier returned to the mathematics he loved.  In his non-official capacity he continued to work with the greatest ardour at his researches on the movements of the planets.  After the death of M. Delaunay, who was accidentally drowned in 1873, Le Verrier was restored to the directorship of the observatory, and he continued to hold the office until his death.

The nature of the researches to which the life of Le Verrier was subsequently devoted are not such as admit of description in a general sketch like this, where the language, and still less the symbols, of mathematics could not be suitably introduced.  It may, however, be said in general that he was particularly engaged with the study of the effects produced on the movements of the planets by their mutual attractions.  The importance of this work to astronomy consists, to a considerable extent, in the fact that by such calculations we are enabled to prepare tables by which the places of the different heavenly bodies can be predicted for our almanacs.  To this task Le Verrier devoted himself, and the amount of work he has accomplished would perhaps have been deemed impossible had it not been actually done.