The urban problems of Paris had been recognized in the 18th century; Voltaire complained about the markets "established in narrow streets, showing off their filthiness, spreading infection and causing continuing disorders." He wrote that the façade of the Louvre was admirable, "but it was hidden behind buildings worthy of the Goths and Vandals." He protested that the government "invested in futilities rather than investing in public works." In 1739 he wrote to the King of Prussia: "I saw the fireworks which they fired off with such management; would rather they started to have a Hôtel de Ville, beautiful squares, magnificent and convenient markets, beautiful fountains, before having fireworks."