1. Galileo and his Telescope Practical Optics and Cosmology Albert Van Helden Rice University University of Utrecht

2. The telescope was invented by children playing with lenses?.....

3. Hans Lipperheys patent application Oktober 1608

4. Jacob Metius of Alkmaar

5. And then there was also Sacharias Jansen

6. Giovanni Battista della Porta 1535-1615 Concave lenticulars show things clearer but smaller. Convex lenticulars show things larger but fuzzy. If you know how to put the two together, you will be able to help near-sighted as well as far-sighted people. Magia Naturalis, 1589

7. Gio. Battista Della Porta to Federico Cesi 28 augustus 1609 e una coglionaria et e preso dal mio libro 9 De refractione

16. Italian Spyglass First half of the 17th century length 21 cm, magnification 4× courtesy of R. Willach

17. French telescope, ca. 1620 length 63 cm, magnification 14× courtesy of R. Willach

36. 16101616 Il saggiatore, 1623