In about 1660, a public test was conducted in Rome to compare the work of two optical-instrument makers: the already-famous Eustachio Divini, and the younger Giuseppe Campani, chiefly known as a clockmaker. The trial, known as the paragone degli occhiali [telescope competition], involved a distance-reading of printed texts. These consisted of experimental optical charts prepared in Florence by the Accademia del Cimento. The charts displayed phrases taken from Dante, Petrarch, and Ariosto, set in characters of various sizes and—to avoid fraud—rearranged to produce meaningless expressions. The charts were gradually moved farther away from the competing telescopes to establish which instrument provided the sharpest image at the greatest distance. The texts were not disclosed to the telescope observers beforehand. The charts may be regarded as the predecessors of the eyecharts used by today's opticians to measure sight. The test was repeated on various occasions in the presence of high-ranking spectators. While the competition ended with no official winner, Campani's telescopes emerged as the more precise. Some of these instruments were added to the Medici collection at the time, and are now preserved at the Museo Galileo of Florence.