After this, in the year 1457, when the very useful method of printing books was discovered by Johann Gutenberg the German, Leon Batista, working on similar lines, discovered a way of tracing natural perspectives and of effecting the diminution of figures by means of an instrument, and likewise the method of enlarging small things and reproducing them on a greater scale; all ingenious inventions, useful to art and very beautiful. In Leon Batista's time Giovanni di Paolo Rucellai wished to build the principal facade of S. Maria Novella entirely of marble at his own expense, and he spoke of this to Leon Batista, who was very much his friend; and having received from him not only counsel, but the actual model, Giovanni resolved to have the work executed at all costs, in order to leave it behind him as a memorial of himself. A beginning having been made, therefore, it was finished in the year 1477, to the great satisfaction of all the city, which was pleased with the whole work, but particularly with the door, from which it is seen that Leon Batista took more than ordinary pains. For Cosimo Rucellai, likewise, he made the design for the palace which that man built in the street which is called La Vigna, and that for the loggia which is opposite to it. In the latter, having turned his arches over columns close together, both in the front and at the ends, since he wished to adhere to this plan and not to make one single arch, he had a certain space left over on each side; wherefore he was forced to make certain projections at the inner corners. And then, when he wished to turn the arch of the inner vaulting, having seen that he could not give it the shape of a half-circle, which would have been flat and awkward, he resolved to turn certain small arches at the corners from one projection to another; and this lack of judgment in design gives us to know clearly that practice is necessary as well as science, for the judgment can never become perfect unless science attains to experience by actual work. It is said that the same man made the design for the house and garden of these Rucellai in the Via della Scala. This house is built with much judgment and very commodious, for, besides many other conveniences, it has two loggie, one facing south and the other west, both very beautiful, and made without arches on the columns, which is the true and proper method that the ancients used, for the reason that the architraves which are placed on the capitals of the columns lie level, whereas a four-sided thing like a curving arch cannot rest on a round column without the corners jutting out over space. The good method, therefore, demands that architraves should rest on columns, and that, when arches are to be turned, pilasters and not columns should be made.