A catalogue of nebulæ and clusters of stars in the southern hemisphere, observed at Paramatta in New South Wales, by James Dunlop, Esq. In a letter addressed to Sir Thomas Makdougall Brisbane, Bart. K. C. B. late Governor of New South Wales. Presented to the Royal Society by John Frederick William Herschel, Esq. Vice President

The observations, of which the results are here given, were made by Mr. Dunlop in the open air, with a 9-feet reflecting telescope, having the clear aperture of the large mirror 9 inches, and fitted up as a meridian telescope; the position of which, and the index error, being ascertained by the passage of known stars. The drawings which accompany the paper were made at the time of observation of the appearances of a great number of nebulæ and clusters, and particularly of the nebulæ major and minor. The paper contains a catalogue and description of 629 nebulæ, arranged in the order of their south polar distance, and in zones for each degree in the order of their right ascension. A few observations are subjoined, describing more particularly the appearance of the nebula minor, which, seen through the telescope, resembles one of the brighter portions of the milky way; of the nebula major, which is brighter, more irregular, and composed of a great number of different parts; and of the dark space on the east side of the cross, or the black cloud, as it is called, which is occasioned by the almost total absence of stars. It is remarked by the author, that neither of the two nebulæ, major and minor, are at present in the place assigned to them by La Caille. He finds also that scarcely any nebulæ exist in a high state of condensation, and very few even in a state of moderate condensation towards the centre. Some have bright points in or near the centre, many of which may be stars; but the greater number of the nebulæ appear only as condensations of the general nebulous matter into faint nebulæ of various forms and magnitudes, generally not well defined; while many of the larger nebulous appearances are resolvable into stars of small magnitudes. But whether nebulæ are universally thus resolvable, is a question of which our instruments are yet incompetent to afford a direct solution, and in the discussion of which we have only analogy as our guide.