Among the great reservoirs, the most noticeable is that of Montmartre, rising high by the side of the church of the Sacré-Cœur, and containing within its gray walls no less than three lakes, one above another. The largest of all these storage basins in the city is that of the Vanne, at the side of the principal entrance to the Parc Montsouris; in its vast, vaulted enclosure, covered with turf, may be stored two hundred and fifty thousand cubic mètres of water. Visitors are admitted to the under vault, where, by the light of torches, the enormous walls and the innumerable columns that sustain this weight are dimly visible. The water of the Avre, drawn from the two sources of the Vigne and Verneuil, is to be stored in the still larger reservoir on the heights of Saint-Cloud, similar in construction and now nearly completed. Each of the three sections in which it is built will contain a hundred thousand cubic mètres. The ancient mediæval methods have all been put away, the inevitable little open gutter running down the middle of the street--celebrated by Boileau and Mme. de Staël, and many others--has long since disappeared, but the water-supply is not yet entirely adequate, and the citizens may still suffer for the lack of a pure liquid to drink,--as they did through so many centuries. It not infrequently happens, as it did in the early autumn of 1898, that several quarters of the city are simultaneously deprived of eau de source, and compelled to use the river-water alone. Every effort is made to avert this--as it is rightly considered--calamity, the streets are placarded with official notices warning the inhabitants of the approaching curtailment of their supply, and they are notified in a similar manner when the scarcity is over. Two solutions have been proposed for this insufficiency, both of them involving such heavy expense that the municipality shrinks from adopting either;--the first, to supply every dwelling with a double set of pipes, one carrying the pure water of the aqueducts, and the other the river-water, forced up into the upper stories; the second is to go as far as the lakes Neuchâtel, or Geneva, for an uncontaminated supply. The complete application of the _tout à l'égout_ system has been delayed by the want of the greatly-increased volume of water necessary for its application, and strong petitions have been presented demanding the postponement of the application of the law of 1894. The present supply is about a hundred and twenty-four litres of eau de source and ninety-six of eau de rivière daily for each inhabitant, but in summer this amount may become greatly diminished. Paris thus stands second in the amount of daily water-supply in the European capitals,--the figures ranging from Rome with four hundred and fourteen litres per capita, daily, to Constantinople with fifteen. London has only a hundred and seventy-three for each inhabitant daily; and Berlin, seventy-three, next to the Turkish capital.