Galileo’s device was a simple telescope — two glass lenses at the ends of a leather tube that magnified objects nine times — and it would forever change our understanding of the universe. Established theories, centuries old, would fall; it would embarrass and anger the Roman Catholic Church; and it would mark the birth of modern astronomy.
But on Aug. 25, 1609, the practical Galileo focused on the telescope’s military benefits: He told the Venetian senators that it would be invaluable in war, since one could see ships sailing into Venice’s harbor a full two hours before they became visible to the naked eye. The Senate, duly impressed, doubled his salary. (The tradition perseveres: Scientists routinely tout military and other applied uses for their research in hopes of securing funding.)
.. and we will try not confuse you with "astrology"! :)