"On Sept. 25th was made my proposal for an Altazimuth Instrument for making observations of the Moon's place more frequently and through parts of her orbit where she could never be observed with meridional instruments; the most important addition to the Observatory since its foundation. The Board of Visitors recommended it to the Admiralty, and the Admiralty sanctioned the construction of the instrument and the building to contain it." The following passage is quoted from the Address of the Astronomer Royal to the Board of Visitors at the Special Meeting of Nov. 10th, 1843: "The most important object in the institution and maintenance of the Royal Observatory has always been the Observations of the Moon. In this term I include the determination of the places of fixed stars which are necessary for ascertaining the instrumental errors applicable to the instrumental observations of the Moon. These, as regards the objects of the institution, were merely auxiliaries: the history of the circumstances which led the Government of the day to supply the funds for the construction of the Observatory shews that, but for the demands of accurate Lunar Determinations as aids to navigation, the erection of a National Observatory would never have been thought of. And this object has been steadily kept in view when others (necessary as fundamental auxiliaries) were passed by. Thus, during the latter part of Bradley's time, and Bliss's time (which two periods are the least efficient in the modern history of the Observatory), and during the latter part of Maskelyne's presidency (when, for years together, there is scarcely a single observation of the declination of a star), the Observations of the Moon were kept up with the utmost regularity. And the effect of this regularity, as regards its peculiar object, has been most honourable to the institution. The existing Theories and Tables of the Moon are founded entirely upon the Greenwich Observations; the Observatory of Greenwich has been looked to as that from which alone adequate observations can be expected, and from which they will not be expected in vain: and it is not perhaps venturing too much to predict that, unless some gross dereliction of duty by the managers of the Observatory should occur, the Lunar Tables will always be founded on Greenwich Observations. With this impression it has long been to me a matter of consideration whether means should not be taken for rendering the series of Observations of the Moon more complete than it can be made by the means at present recognized in our observatories."--In illustration of the foregoing remarks, the original inscription still remaining on the outside of the wall of the Octagon Room of the Observatory may be quoted. It runs thus: 'Carolus II's Rex Optimus Astronomiae et Nauticae Artis Patronus Maximus Speculam hanc in utriusque commodum fecit Anno D'ni MDCLXXVI Regni sui XXVIII curante Iona Moore milite RTSG.'