One day as Philip stood at the window of his palace, where he was wont to amuse himself by watching the Seine flow by, some carts rattled along the muddy road beneath the window and stirred so foul and overpowering an odour that the king almost fell sick. Next day the provost and the sheriffs and chief citizens were sent for and ordered to set about paving the city with stone. The work was not however completed until the reign of Charles V., a century and a half later. It was done well and lasted till the sixteenth century, when it was replaced by the miserable cobbles, known as the pavement of the League. Whether the city grew much sweeter is doubtful; certainly Paris in the sixteenth and seventeenth centuries was as evil-smelling as ever. Montaigne, in the second half of the sixteenth century, complains that the acrid smell of the mud of Paris weakened the affection he bore to that fair city, and Howell writes in 1620, "the city is always dirty, and by perpetual motion the mud is beaten into a thick, black and unctuous oil that sticks so that no art can wash it off, and besides the indelible stain it leaves, gives so strong a scent that it may be smelt many miles off, if the wind be in one's face as one comes from the fresh air of the country." [Illustration: WALL OF PHILIPPE AUGUSTE, COUR DE ROUEN.] The great fortified wall of Philip Augustus began at the north-west water-tower, which stood just above the present Pont des Arts, and passed through the quadrangle of the Louvre where a line on the paving marks its course to the Porte St. Honoré, near the Oratoire. It continued northwards by the Rue du Jour to the Porte Montmartre, whose site is marked by a tablet on No. 30 Rue Montmartre. Turning eastward by the Painters' Gate (135 Rue St. Denis) and the Porte St. Martin, near the Rue Grenier St. Lazare, the fortification described a curve in a south-easterly direction by the Rue des Francs Bourgeois, where traces of the wall have been found in the Cour de l'Horloge of the Mont de Piété, and of a tower at No. 57. The line of the wall continued in the same direction by the Lycée Charlemagne, No. 131 Rue St. Antoine, where stood another gate, to the north-east water-tower, known as the Tour Barbeau, which stood near No. 32 Quai des Célestins. The opposite or southern division began at the south-east water-tower, La Tournelle, and the Gate of St. Bernard on the present Quai de la Tournelle, and went southward by the Rues des Fossés, St. Bernard and Cardinal Lemoine, to the Porte St. Victor, near No. 2 Rue des Ecoles. The wall then turned westward by the Rue Clovis, where at No. 7 one of the largest and best-preserved remains may be seen. It enclosed the abbey of St. Geneviève, and the Pantheon stands on the site of the Porte Papale. The south-western angle was turned near the end of the Rue Soufflot and the beginning of the Rue Monsieur le Prince. In a northerly direction it