and Belgrand built new sewer tunnels under each sidewalk of the new boulevards. The sewers were designed to be large enough to evacuate rain water immediately; the large amount of water used to wash the city streets; waste water from both industries and individual households; and water that collected in basements when the level of the Seine was high. Before Haussmann, the sewer tunnels (featured in Victor Hugo's Les Miserables) were cramped and narrow, just high and 75 to 80 centimeters (2 ft 6 in) wide. The new tunnels were 2.3 meters (7 ft 6 in) high and 1.3 meters (4 ft 3 in) wide, large enough for men to work standing up. These flowed into larger tunnels that carried the waste water to even larger collector tunnels, which were high and wide. A channel down the center of the tunnel carried away the waste water, with sidewalks on either side for the égoutiers, or sewer workers. Specially designed wagons and boats moved on rails up and down the channels, cleaning them. Belgrand proudly invited tourists to visit his sewers and ride in the boats under the streets of the city. The underground labyrinth built by Haussmann also provided gas for heat and for lights to illuminate Paris. At the beginning of the Second Empire, gas was provided by six different private companies. Haussmann forced them to consolidate into a single company, the Compagnie parisienne d'éclairage et de chauffage par le gaz, with rights to provide gas to Parisians for fifty years. Consumption of gas tripled between 1855 and 1859. In 1850 there were only 9000 gaslights in Paris; by 1867, the Paris Opera and four other major theaters alone had fifteen thousand gas lights. Almost all the new residential buildings of Paris had gaslights in the courtyards and stairways; the monuments and public buildings of Paris, the arcades of the Rue de Rivoli, and the squares, boulevards and streets were illuminated at night by gaslights. For the first time, Paris was the City of Light. Critics of Haussmann's Paris Contemporaneous Haussmann's renovation of Paris had many critics during his own time. Some were simply tired of the continuous construction. The French historian Léon Halévy wrote in 1867, "the work of Monsieur Haussmann is incomparable. Everyone agrees. Paris is a marvel, and M. Haussmann has done in fifteen years what a century could not have done. But that's enough for