APPENDIX.

623

appear from most of the observations that it is not a distinct appendage ofthe planet, but simply a continuation of the inner bright ring.

On the 24th of October, 1851, Mr. Lassell discovered two new satellitesrevolving round Uranus . He has subsequently succeeded in seeing themwith his powerful reflector, on every occasion on which he looked for them.He finds that the observations may be pretty well satisfied by supposingthe period of the inner satellite to be 2.506 days, and that of the outersatellite to be 4.150 days. It appears, therefore, that they are interior tothe two bright satellites discovered by Sir William Herschel in 1787.From the diagram of their positions inserted in the Monthly Proceedingsof the Astronomical Society for November, 1851, they appear, like theother satellites, to revolve in orbits nearly perpendicular to the plane of theecliptic.

It has been mentioned (p. 139) that a comet discovered byM. Faye, in theyear 1843, was found to revolve in an elliptic orbit, and that its perturba-tions for the ensuing revolution were calculated by Le Verrier , whoarrived at the conclusion that its passage through the perihelion wouldtake place on the 2nd of April, 1851. It is a gratifying fact that thecomet has actually returned at the appointed time. It was first seen byProf. Challis, with the Northumberland refractor, on the 28th ofNovember, 1850. The observations of its apparent position have beenfound to present a remarkable agreement with the corresponding resultsderivable from the calculations of M. Le Yerrier.

Allusion has been made at page 243 to the discovery of a small ultra-zodiacal planet (Metis ) at the observatory of E. Cooper, Esq., of Markree,in the north of Ireland . An achievement of vastly greater importance hassince emanated from that observatory in the shape of a catalogue of 14,888stars near the ecliptic, the places of which, in general, are not to befound in any catalogues hitherto published. This catalogue was constructedfrom observations made in the years 1848, 1849, and 1850, and was pub-lished in 1851, the expense of printing 1 having been defrayed by the Go-vernment, upon the recommendation of the Royal Society . A secondcatalogue, destined to contain the places of about 12,000 additional stars,observed in the year 1851, is in the course of preparation at the sameobservatory. Mr. Cooper and his active assistant, Mr. Graham, are alsoengaged in executing a series of celestial maps upon a magnificent scale.Each map has a range of 8° both in right ascension and in declination.The scale is four times larger than that of the Berlin maps. It is con-templated to insert in these maps all the stars within their range whichhave either been observed at Markree, or have been already published inother catalogues. The epoch of reduction is 1850.0. The advantageswhich cannot fail to accrue to astronomical science from the constructionof these maps is incalculable. It must be acknowledged that the laboursat Markree Observatory exhibit a loftiness of aim as well as a unity ofdesign, and a spirit of skilful perseverance, which not only serves effec-tually to remove that establishment from the category of mere amateurobservatories, but entitles it to an honourable place in the highest classof those institutions that have been founded for the promotion of astro-nomical science.

In concluding this note it may be stated, that the Astronomer Royalhas now (February, 1852) completed the arrangements at the RoyalObservatory for recording transits of stars by means of an electro-magneticapparatus. The accuracy of this method may be relied on to the twentieth