Bbrunelleski himself invented such mechanisms as hoist, cranes and horizontal winch. According to the well-known biographer Dgordgo Vasari (1511-1574), for the purpose of the elimination of the rival Brunelleski pretended to be sick so that Ghiberti should perform work by himself. The latter did not know how to carry out the construction, and therefore works stopped. Works were renewed only if Brunelleski again appeared at the construction site. Thus, Brunelleski affirmed his authority.