Telescope earliest existing record of a telescope was a 1608 patent submitted to the government in the Netherlands by Middelburg spectacle maker Hans Lippershey for a refracting telescope. The actual inventor is unknown but word of it spread through Europe. [[Galileo Galilei|Galileo]] heard about it and, in 1609, built his own version, and made his telescopic observations of celestial objects. The idea that the [[Objective (optics)|objective]], or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope. The potential advantages of using [[parabolic reflector|parabolic mirrors]]—reduction of [[spherical aberration]] and no
Zacharias Janssen people he had the local magistrate interview were trying to recount details 50 or 60 years after the fact and Boreel may have confused the names of spectacle makers from his childhood. He may have also been confused about a microscope built by another optician for Drebbel, claiming it was built by Zacharias Janssen. An investigation begun in 1816 in preparation for a memorial to commemorate Janssen as the inventor of the telescope and microscope turned up further problems with the claim including the Lippershey and Metius patent applications, Janssen late 1585 date of birth, and no record of him