The sculptor Jacopo, son of Maestro Piero di Filippo of La Quercia, a place in the district of Siena, was the first--after Andrea Pisano, Orcagna, and the others mentioned above--who, labouring in sculpture with greater zeal and diligence, began to show that it was possible to make an approach to nature, and the first who encouraged the others to hope to be able in a certain measure to equal her. His first works worthy of account were made by him in Siena at the age of nineteen, with the following occasion. The people of Siena having their army in the field against the Florentines under the captainship of Gian Tedesco, nephew of Saccone da Pietramala, and of Giovanni d'Azzo Ubaldini, this Giovanni d'Azzo fell sick in camp and was carried to Siena, where he died; wherefore, being grieved at his death, the people of Siena caused to be made for his obsequies, which were most honourable, a catafalque of wood in the shape of a pyramid, and on this they placed the statue of Giovanni himself on horseback, larger than life, made by the hand of Jacopo with much judgment and invention. For he, in order to execute this work, discovered a method of making the skeletons of the horse and of the figure which had never been used up to that time--namely, with pieces of wood and planking fastened together, and then swathed round with hay, tow, and ropes, the whole being bound firmly together; and over all there was spread clay mixed with paste, glue, and shearings of woollen cloth. This method, truly, was and still is better than any other for such things, for, although the works that are made in this fashion have the appearance of weight, none the less after they are finished and dried they turn out light, and, being covered with white, look like marble and are very lovely to the eye, as was the said work of Jacopo. To this it may be added that statues made in this fashion and with the said mixtures do not crack, as they would do if they were made simply of pure clay. And in this manner are made to-day the models for sculpture, with very great convenience for the craftsmen, who, by means of these, have ever before them the patterns and the true measurements of the sculptures that they make; and for this method no small obligation is owed to Jacopo, who is said to have been its inventor.