Casting a retrospect over the ages that have passed in review, how are we struck with the slow and painful growth of human invention! The collective energies and discoveries of a thousand years were required to rear the arts of Greece--not to their perfection, but to the state where the first decided approaches to it commence. Such is the length of time from the first feeble glimmerings of imitative art to the era of Dipænus and Scyllis, Bupalus and Anthermus. The interval of forty years occupied by these artists, from the fiftieth to the sixtieth Olympiad, may be considered as terminating the old, and introducing the new school. The art was now in possession of all the means and instruments, the correct application of which bound the aspirings and the praise of mediocrity, but which merely become subservient to the aims of loftier minds. During part of this period, also, these means were industriously, and with daily improving skill, employed. From this date to the battle of Marathon, an interval of fifty-eight years, improvement was rapid in every corner of Greece and her colonies. Fortunately, also, the movement then given to Sculpture was one of diffuse activity, not an influence derived from, and sustained amongst, a few leading minds, whose authority might thus have operated fatally, by binding down to fixed and imperfect modes the aspirings of future genius. This advantage was secured by the number of independent states forming the Grecian confederacy, a constitution, which, throughout the whole history of ancient art, exercised the most beneficial effects, both by preventing mannerism, in taste, and by nourishing emulation. The Persian invasion, the victories of Marathon, Salamis, and Platea, awakened a new energy in the moral character of Greece, infusing at the same time into her institutions a vigour and a stability before unknown. From the elevation she had now attained among the nations of the earth, her genius rushed forward as from vantage ground. In every field of mental enterprise, indeed, a certain preparation had already been made, and in some the best exertions had long been achieved. In poetry a sublimity had been attained, which has yet set at nought all succeeding rivalry. But in that knowledge, and in those arts, which depend less upon individual eminence, and more upon the circumstances of the times, and upon a strong national interest,--in all those studies which embrace numbers by their consequences or their success, which demand the union of patient perseverance with high talent, and finally, which pertain to the business of public life, and require deep insight into the nicer distinctions of human character--all, from this happy era, with an almost supernatural progress, attained maturity.