The excavation of the sewer of Paris has been no slight task. The last ten centuries have toiled at it without being able to bring it to a termination, any more than they have been able to finish Paris. The sewer, in fact, receives all the counter-shocks of the growth of Paris. Within the bosom of the earth, it is a sort of mysterious polyp with a thousand antennae, which expands below as the city expands above. Every time that the city cuts a street, the sewer stretches out an arm. The old monarchy had constructed only twenty-three thousand three hundred metres of sewers; that was where Paris stood in this respect on the first of January, 1806. Beginning with this epoch, of which we shall shortly speak, the work was usefully and energetically resumed and prosecuted; Napoleon built⁠—the figures are curious⁠—four thousand eight hundred and four metres; Louis XVIII , five thousand seven hundred and nine; Charles X