Thirty years ago, at the epoch of the insurrection of the 5th and 6th of June, it was still, in many localities, nearly the same ancient sewer. A very great number of streets which are now convex were then sunken causeways. At the end of a slope, where the tributaries of a street or crossroads ended, there were often to be seen large, square gratings with heavy bars, whose iron, polished by the footsteps of the throng, gleamed dangerous and slippery for vehicles, and caused horses to fall. The official language of the Roads and Bridges gave to these gratings the expressive name of Cassis. 103