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Astronomy stands justly at the head of the physical sciences. The present meetingof the British Association, if it did not offer any very great and important novelty, was still one of triumphant congratulation at the termination of several long continued labours. It is well known,that from 3000l. to 4000l. have been expended by the association in furtherance of this branch of inquiry; and the manner in which this has chiefly been expended has been in the extensive reductions to be made for the formation of the Catalogue of Stars, formerly known as that of the Astronomical Society, but now as that of the British Association; the reduction of the astronomical observations in Lacaille's Catalogue of the Stars, and of the stars in the Histoire Celeste of Lalande.

Mr. Baily read a report on the last of these reductions, the whole of which, with a few omissions, he stated, had been reduced, being in number upwards of 47,000 stars. Mr. B. also reported, on the British Association Catalogue of Stars, in which the calculations of the proper places of the stars, with the logarithms of the proper constants &c., are furnished for nearly 83,000 stars. Sir J. Herschell reported on the reduction of Lacaille's stars, made by a committee, and under the superintendence of Mr. Henderson, the whole of which work was now completed; and the resulting catalogue, arranged in the order of right ascension, was written out for the press. The number of stars reduced was about 10,000.

Apart from these elaborate reports, was a very valuable memoir on astronomical clocks, by Professor Bessel, of Königsberg, whom Sir W. Hamilton, in great modesty, places at the head of living astronomers. Mr. Talbot also communicated an important memoir on the improvement of telescopes.

Mr. Dent also made several interesting communications chiefly on the subject of chronometers.

The science of optics,which has attracted so much attention, and made so much progress of late years, was chiefly represented, on the present occasion, by Sir David Brewster, who made altogether nine different communications on the subject. These, in part, concerned the action of the media of different coloured rays; and contained an account of certain luminous bands in the spectra of various flames, of luminous lines in certain flames corresponding to the defective lines in the sun's light, and of the structure of a part ofthe solar spectrum, hitherto unexamined.

An important and interesting communication, which involved the much-debated question of the undulatory theory, was made by Sir David; in it he described what he considered, as a new property of light, a polarity in the simple rays. The subject, although discussed at previous meetings of the association, was opportunely brought forward on the present occasion, as there were present most of those who, in this country, have devoted their attention to the investigation of the physical properties of light.

The leading communication upon this very interesting branch of inquiry was the report, by Sir J. Herschell and Colonel Sabine, on the great system of magnetic and meteorological observations, carried on at the same time by naval expeditions and fixed land observations, a system which has been truly designated as the greatest combined scientific operation the world has ever yet witnessed. The report of progress was highly satisfactory. The extent of operations is now vastly increased, by new foreign establishments observing upon the same concerted plan, and at the same hours—by the adoption of a system of colonial and national magnetic surveys, based upon, and correlative with, the fundamental determinations at the fixed magnetic centres—and by the introduction of new instruments and processes of observation, affording great facilities for magnetic determinations both by land and by sea. The annual reports of the British Association could not be better modelled than after the present one on magnetism—business-like, and noticing every memoir and publication on the subject. In furtherance of the same branch of inquiry, there was also a communication from Sir Thomas Brisbane; another, by Dr. Scoresby, on improved permanent magnets, and the modes of determining their powers; and a further one, by Professor Marianini, on the magnetic action of momentaneous currents. In addition to these, Dr. Reade read some experiments on magnetic polarity connected with electricity.

The number of communications in this branch of knowledge amounted to eight. Among these were two interesting ones on anemometers, by Sir D. Brewster and