music, truly represented Paradise. In addition to this, in order
to be able to open and close that Heaven, Filippo had made two great
doors, each five braccia both in length and breadth, which had rollers
of iron, or rather, of copper, in certain grooves running horizontally;
and these grooves were oiled in a manner that when a thin rope, which
was on either side, was pulled by means of a little windlass, any one
could open or close the Heaven at his pleasure, the two parts of the
door coming together or drawing apart horizontally along the grooves.
And these two doors, made thus, served for two purposes: when they were
moved, being heavy, they made a noise like thunder; and when they were
closed, they formed a platform for the apparelling of the angels and
for the making of the other preparations which it was necessary to carry
out within. These engines, made thus, together with many others, were
invented by Filippo, although others maintain that they had been
invented long before. However this may be, it was well to speak of them,
seeing that they have gone completely out of use.

But to return to Filippo himself; his renown and his name had grown so
great that he was sent for from far distant places by all who wished to
erect buildings, in their desire to have designs and models by the hand
of so great a man; and to this end the most powerful means and
friendships were employed. Wherefore the Marquis of Mantua, among
others, desiring to have him, wrote with great insistence to the
Signoria of Florence, by whom he was sent to that city, where he gave
designs for dykes on the Po and certain other works according to the
pleasure of that Prince, who treated him very lovingly, being wont to
say that Florence was as worthy to have Filippo as a citizen as he was
to have so noble and beautiful a city for his birthplace. In Pisa,
likewise, Count Francesco Sforza and Niccolo da Pisa, being surpassed by
him in the making of certain fortifications, commended him in his
presence, saying that if every State possessed a man like Filippo it
would be possible to live in security without arms. In Florence, also,
Filippo gave the design for the house of the Barbadori, near the tower
of the Rossi in the Borgo San Jacopo, but it was not put into execution;
and he also made the design for the house of the Giuntini on the Piazza
d'Ognissanti, on the Arno. Afterwards, the Captains of the Guelph party
in Florence, wishing to build an edifice