Leave the Choir by the door by which you entered it, and seat yourself for a while at the intersection of the Nave and Transepts, in order to gain a good idea of the Apse, the Choir, and the general arrangement of the shortly cruciform building. Observe the beautiful vaulting of the roof, and the extent to which the church is born on its piers alone, the intervening walls (pierced by windows and triforium-arches) being intended merely for purposes of enclosure. Note also the fine ancient glass of the rose windows. Quit the church by the North or Left Aisle, and come back to it often. Those who are not afraid of a spiral staircase, mostly well lighted, should =ascend= the Left or =North Tower= (tickets fifty cents. each, at the base of the tower). Stop near the top to inspect the gallery, with the famous birds and demons. The view hence embraces from the front the Tower of St. Jacques; behind it, the hill of Montmartre, with the white turrets and cupolas of the church of the Sacré-Cœur; a little to the L, St. Eustache; then the Tribunal de Commerce; St. Augustin; the Louvre; the roof of the Ste. Chapelle; the Arc de Triomphe; the twin towers of the Trocadéro; the Eiffel Tower; the gilded dome of the Invalides; St. Sulpice, etc. The Île de la Cité is well seen hence as an island. Note also the gigantic size of the open screen, which looked so small from below. Ascend to the top. Good general panorama of the town and valley. This is the best total view of Paris, far superior to that from the Eiffel Tower, being so much more central. Return by the Pont d’Arcole (whence you get a capital notion of the bifurcation of the Seine around the Île St. Louis), and then pass the modern Hôtel-de-Ville, with St. Gervais behind it, on your way home to the Rue de Rivoli. [Illustration: [Map of] HISTORIC PARIS] MAP OF HISTORIC PARIS.