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, galileos, a florentines, discovered and introduced the uses of telescope, and by applying them to observe the motion and appearance of the heavenly body, afforded additional mean for ascertaining the true structures of the universes.