will, was compelled to allow him to follow the bent of his genius:  he accordingly placed him, at a proper age, in the Guild of the Goldsmiths, that he might acquire the art of design.  Filippo soon became a proficient in the setting of precious stones, which he did much better than any old artists in the vocation.  He also wrought in niello, and executed several figures which were highly commended, particularly two figures of Prophets, for an altar in the Cathedral of Pistoja.  Filippo next turned his attention to sculpture, and executed works in basso-relievo, which showed an extraordinary genius.  Subsequently, having made the acquaintance of several learned men, he began to turn his attention to the computation of the divisions of time, the adjustment of weights, the movement of wheels, etc.  He next bent his thoughts to the study of perspective, to which, before his time, so little attention was paid by artists, that the figures often appeared to be slipping off the canvas, and the buildings had not a true point of view.  He was one of the first who revived the Greek practice of rendering the precepts of geometry subservient to the painter; for this purpose, he studied with the famous geometrician Toscanelli, who was also the instructor, friend, and counsellor of Columbus.  Filippo pursued his investigations until he brought perspective to great perfection; he was the first who discovered a perfectly correct method of taking the ground plan and sections of buildings, by means of intersecting lines—­“a truly ingenious thing,” says Vasari, “and of great utility to the arts of design.”  Filippo freely communicated his discoveries to his brother artists.  He was imitated in mosaic by Benedetto da Macano, and in painting by Masaccio, who were his pupils.  Vasari says Brunelleschi was a man of such exalted genius, that “we may truly declare him to have been given to us by Heaven, for the purpose of imparting a new spirit to architecture, which for hundreds of years had been lost; for the men of those times had badly expended great treasures in the erection of buildings without order, constructed in a most wretched manner, after deplorable designs, with fantastic inventions, labored graces, and worse decorations.  But it then pleased Heaven, the earth having been for so many years destitute of any distinguished mind and divine genius, that Filippo Brunelleschi should leave to the world, the most noble, vast, and beautiful edifice that had ever been constructed in modern times, or even in those of the ancients; giving proof that the talent of the Tuscan artists, although lost for a time, was not extinguished.  He was, moreover, adorned by the most excellent qualities, among which was that of kindliness, insomuch that there never was a man of more benign and amicable disposition; in judgment he was calm and dispassionate, and laid aside all thought of his own interest and even that of his friends, whenever he perceived the merits and talents of others to demand that he should do so.