sentence: So late as 1610, Galileo, a Florentine, discovered and introduced the use of telescopes, and by applying them to observe the motions and appearances of the heavenly bodies, afforded additional means for ascertaining the true structure of the universe.
modified: fix grammar: So late as 1610, Galileo, an Florentine, discovered and introduced the use of telescopes, and by applying them to observe the motions and appearances of the heavenly bodies, afforded additional means for ascertaining the true structure of the universe.