CHAPTER II.

FAILING HEALTH AND LOSS OF SIGHT.

Galileo’s Labours at Arcetri.—Completion of the “Dialoghi delle nuove Scienze.”—Sends it to the Elzevirs at Leyden.—Method of taking Longitudes at Sea.—Declined by Spain and offered to Holland.—Discovery of the Libration and Titubation of the Moon.—Visit from Milton.—Becomes blind.—Letter to Diodati.—On a hint from Castelli, petitions for his Liberty.—The Inquisitor to visit him and report to Rome.—Permitted to live at Florence under restrictions.—The States-General appoint a Delegate to see him on the Longitude question.—The Inquisitor sends word of it to Rome.—Galileo not to receive a Heretic.—Presents from the States-General refused from fear of Rome.—Letter to Diodati.—Galileo supposed to be near his end.—Request that Castelli might come to him.—Permitted under restrictions.—The new “Dialoghi” appear at Leyden, 1638.—They founded Mechanical Physics.—Attract much notice.—Improvement of health.—In 1639 goes to Arcetri again, probably not voluntarily 284