Nevertheless, the sewerage system of Paris is conceived and carried out in its general plan with an appreciation of the requirements of modern sanitary science and an intelligent employment of the science of the engineer that are quite admirable. The methods of disposing of the city's refuse in use by many American municipalities, as those of New York and Chicago, are, by comparison, but dull and stupid perpetuation of antiquated traditions. The animated controversy over the great question of _Tout à l'égout_, "all refuse to the sewer," was not finally settled till 1894, and this method has as yet not been applied to all the quarters of the city, as stated above, but is being gradually extended, and nothing but time seems to be wanting to bring about in this capital a complete solution of one of the most difficult problems of material civilization. The object of the Parisian method is to avoid fouling the Seine in any way, and to utilize all the city's refuse, instead of throwing it away or allowing it to accumulate, a menace to health and a hideous nuisance. By an excellent system of underground conduits, well lighted and ventilated, the sewage and the rain-water are collected, carried by canals and pipes outside the city, and applied, after proper treatment, to the fertilization of certain arid tracts of land farther down the river. The principal agent in this "hygienic transformation of Paris" was the engineer Belgrand, who, at his death, in 1870, had increased the length of the municipal sewers from two hundred and twenty-eight kilomètres in 1860 to six hundred. It has now attained a total of fourteen hundred and twenty-one, representing a capital of a hundred and fifty millions of francs. The first principle of Belgrand's system was to avoid any discharge from the sewers into the river during its course through Paris. The great main sewer, the _collecteur général_, of the right bank, called the collecteur d'Asnières, follows the quais from the basin of the Arsenal to the Place de la Concorde, then burrows under the heights of the Batignolles to reach Clichy; the collecteur général of the left bank, which includes the poor little Bièvre, traverses the bed of the Seine by means of a siphon at the Pont de l'Alma and is prolonged by the collecteur Monceau, which passes under the hill of the Place de l'Étoile to join the collecteur d'Asnières. A third collecteur, known as the _départemental_, or _du Nord_, at a higher level, receives the drainage of Belleville and Montmartre, and issues from the city by the Porte de La Chapelle to reach the Seine at Saint-Denis. A new siphon, constructed under the Seine in 1895 and 1896, unites the collecteur général of the left bank to the collecteur d'Asnières. The sewage of the Iles Saint-Louis and de la Cité is carried by two other siphons to the collecteurs of the quais of the right and left banks.