The murmurings were now silenced, and meanwhile, on seeing that building being raised so readily, men had come to recognize the genius of Filippo; and it was already held by those who were not prejudiced that he had shown such courage as perchance no ancient or modern architect had shown in his works. This came to pass because he brought out his model, wherein all could see how much thought he had given to the planning of the staircases and of the lights both within and without, in order that no one might be injured in the darkness by reason of fear, and how many diverse balusters of iron he had placed where the ascent was steep, for the staircases, arranging them with much consideration. Besides this, he had even thought of the irons for fixing scaffoldings within, in case mosaics or paintings had ever to be wrought there; and in like manner, by placing the different kinds of water-conduits, some covered and some uncovered, in the least dangerous positions, and by duly accompanying these with holes and diverse apertures, to the end that the force of the winds might be broken and that neither exhalations nor the tremblings of the earth might be able to do any harm, he showed how great assistance he had received from his studies during the many years that he stayed in Rome. And in addition, when men considered what he had done in the way of dove-tailing, joining, fixing, and binding together the stones, it made them marvel and tremble to think that one single mind should have been capable of all that the mind of Filippo had proved itself able to execute. So greatly did his powers continue to increase that there was nothing, however difficult and formidable, that he did not render easy and simple; and this he showed in the lifting of weights by means of counterweights and wheels, so that one ox could raise what six pairs could scarcely have raised before.