For the regulation of offices Cosimo employed the revolutionary machinery which was in theory the ultimate enforcement of popular sovereignty. The _balia_ which had recalled the Medici in 1434 had received from the parliament full power to reform the state. Every five years this power was renewed—in 1439, 1444, 1449, and 1454. The most important act of the _balia_ was the appointment of ten _accoppiatori_ to superintend the filling of the bags with the names of those who were eligible for office. This was in itself a fairly ample assurance that no opposition to the Medici could be anticipated from the magistracy; and to make it doubly sure, the names of the gonfalonier and priors were selected every two months by the _accoppiatori_. They were made, as the phrase went, not by lot, but by hand. But as time went on, this prolonged departure from normal procedure gave rise to grumbling; and as there were good reasons for avoiding at the moment any appearance of disunion in the city, Cosimo determined to yield. In 1455 the _balia_, which had been renewed the year before, was abolished, and the practice of drawing the names of the signoria was revived. The concession was more apparent than real; for the bags had only recently been refilled, and three years would elapse before a new _squittinio_ would be necessary. For that time the ascendency of the Medici party was secure, and before it had elapsed measures might be taken to prolong it. But that the revival of liberty was of some moment is proved by the proposal in the signoria of January 1458 to restore the _catasto_. Cosimo’s partisans urged him to employ energetic measures to defeat a scheme which attacked their own pockets. But he was not unwilling to teach them how dependent they were upon his support, and he allowed the system of strict and impartial assessment to be revived.