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
The Netherlands in World War I citizens were in demand as spies, as they could travel freely throughout Europe. Some of these spies were executed for espionage. Haicke Janssen and Willem Roos, two unemployed Dutch sailors, were executed in 1915. Exotic dancer and courtesan Mata Hari, convicted of spying for Germany in France, was executed in 1917. In total seven Dutch citizens were executed by the British, French, and Germans. Many more were imprisoned. The Netherlands in World War I The Kingdom of the Netherlands was neutral during World War I. This stance arose partly from a strict policy of neutrality in international affairs that started