PHYSICAL AND MATHEMATICAL SCIENCES. 379

nised in the observations of the most distant epochs, andthe memory of Laplace will be cherished in their re-currence. In the lunar motions will be found thosechanges which will be the fulfilment of his predictions;and the completion of the long periods of the greatinequalities of Jupiter and Saturn, will recall his inves-tigations who was the first to examine and explain theirlaws.

The whole course and manner of his life was regu-lated with a sole view to the purposes of philosophicinvestigation. He devoted the energies of his existenceto his labours in interpreting the mechanism of thematerial world; he dedicated to science a life of re-search ; and science, in return, has conferred on him animmortality of fame.

Among the most valuable labours of his successors wemay enumerate the publication of the “ Theoria Mo.tus,” &c. by Gauss, in 1809 ; the masterly researcheson the attraction of spheroids, in the same and followingyear, by Mr. Ivory (almost the only British philosopherwho, till very lately, attained any high distinction inthese researches); the investigation of Gauss, on thesame subject, in 1810 ; and of Bessel, on the perturb-ations, in 1824. Whilst the researches of Messrs. Lub-bock and Ivory, on the same subject, in 1830 to 1832;and those of Professor Airy, on the figure of the earthand on the solar and planetary theories; and of Enckeon the physical theory of his comet; may, perhaps, beconsidered as some of the most remarkable among thesimilar investigations of the present day.

Plane Astronomy.

In astronomical observation, the period since thetime of Newton has, indeed, been productive of mostvaluable discoveries. The immense improvement inthe construction of astronomical instruments, and in theart of observing, has been naturally followed by a highlyincreased accuracy of results, and numerous accessions