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
Water supply and sanitation in the Netherlands Water supply and sanitation in the Netherlands "This article was written in 2008 with some updates in 2012. Please feel free to further update it, if need be." Water supply and sanitation in the Netherlands is provided in good quality and at a reasonable price to the entire population. Water consumption is one of the lowest in developed countries at 128 litres per capita per day and water leakage in the distribution network is one of the lowest in the world at only 6%. A large array of institutions is responsible for providing water and sanitation services: 10 regional water