But though he had the gift of genius, Leonardo took as much trouble with his work as if he had just been an ordinary child, with his whole future life depending on his industry. And as some of you are perhaps fond of drawing, you may like to hear how one of the greatest artists in the world set about his pictures. First he took a handful of clay and poked it and pinched it until he had got his figure exactly as he wanted it to be. Then he dipped pieces of soft material in plaster, and arranged them in folds over the naked figure. Often the stuff was too stiff and would not go in the proper lines, but long ago Leonardo had learned that no man could be an artist of any kind unless he was possessed of endless patience, and he would sit for hours over his figure, taking the drapery off and trying it afresh, till at length it assumed exactly the right shape. As soon as he had a model precisely to his mind, he would stretch a bit of very fine cambric or linen, that was old and soft, upon a board, and on this--or sometimes on paper--he would copy his figure in pencil. As he grew older, Verrocchio would teach him how you could raise heavy weights by the help of levers or cranes, how to draw up water from immense depths, or how to tunnel through mountains--for the Italians have always been famous for their skill as engineers. But it was the boy Leonardo, and not the man Verrocchio, who invented the plan of so altering the course of the river Arno that a canal might be cut between the cities of Florence and Pisa. Leonardo did not live to see this done, but two hundred years after his death a pupil of the astronomer Galileo executed it after his scheme, for the Medici ruler of Florence. He was very anxious also to raise the Church of San Giovanni and to rest it on stone 'steps,' as he called them, and showed the Signory or governing citizens of Florence how it could be done. And, says his chronicler, so persuasive was his tongue and so good seemed his reasons that while he was speaking he moved them to belief in his words, although out of his presence they all well knew it was impossible. _Was_ it? one wonders now.