This portion of Grenelle, lying between the Champ de Mars and the densely populated streets of the centre of the district, has an aspect all its own, characterized by vast bare expanses, and long and almost deserted streets running at right angles and fringed by factories with lofty, interminable gray walls. During work-hours nobody passes along these streets, and on raising one's head one sees only lofty chimneys belching forth thick coal smoke above the roofs of big buildings with dusty window panes. And if any large cart entrance happens to be open one may espy deep yards crowded with drays and full of acrid vapor. The only sounds are the strident puffs of jets of steam, the dull rumbling of machinery, and the sudden rattle of ironwork lowered from the carts to the pavement. But on Sundays the factories do not work, and the district then falls into death-like silence. In summer time there is but bright sunshine heating the pavement, in winter some icy snow-laden wind rushing down the lonely streets. The population of Grenelle is said to be the worst of Paris, both the most vicious and the most wretched. The neighborhood of the École Militaire attracts thither a swarm of worthless women, who bring in their train all the scum of the populace. In contrast to all this the gay _bourgeois_ district of Passy rises up across the Seine; while the rich aristocratic quarters of the Invalides and the Faubourg St. Germain spread out close by. Thus the Beauchêne works on the quay, as their owner laughingly said, turned their back upon misery and looked towards all the prosperity and gayety of this world. Mathieu was very partial to the avenues, planted with fine trees, which radiate from the Champ de Mars and the Esplanade des Invalides, supplying great gaps for air and sunlight. But he was particularly fond of that long diversified Quai d'Orsay, which starts from the Rue du Bac in the very centre of the city, passes before the Palais Bourbon, crosses first the Esplanade des Invalides, and then the Champ de Mars, to end at the Boulevard de Grenelle, in the black factory region. How majestically it spread out, what fine old leafy trees there were round that bend of the Seine from the State Tobacco Works to the garden of the Eiffel Tower! The river winds along with sovereign gracefulness; the avenue stretches out under superb foliage. You can really saunter there amid delicious quietude, instinct as it were with all the charm and power of Paris.