piers in forming the supports of the first storey some 170 feet above the base. The arches which spring from the ground and rise nearly to the level of these girders are not so much intended to add to the strength of the structure as to increase its architectural effect. The first storey stands about 180 feet above the ground, and is provided with arcades, from which fine views of Paris may be obtained. Here there are spacious restaurants of four different nationalities. And in the centre of the second storey (380 feet high) is a station where passengers change from the inclined lifts to enter other elevators that ascend vertically to the higher stages of the tower. On the third storey, 900 feet above the ground, there is a saloon more than 50 feet square, completely shut in by glass, whence a vast panorama may be contemplated. Above this again are laboratories and scientific observatories, and, crowning all, is the lighthouse, provided with a system of optical apparatus for projecting the rays from a powerful electric light. This light has been seen from the Cathedral at Orléans, a distance of about 70 miles. [Illustration: FIG. 26_c_.—_The Eiffel Tower._ ] The buildings of the Paris Exhibition of 1889 are themselves splendid examples, not only of engineering skill, but of good taste and elegant design in iron structures and their decorations. The vast _Salle des Machines_ (machinery hall) exceeds in dimensions anything of the kind in existence, for it is nearly a quarter of a mile long, and its roof covers at one span its width of 380 feet, rising to a height of 150 feet in the centre. This great hall is to remain permanently, as well as the other principal galleries with their graceful domes. The Eiffel Tower having proved one of the most striking features of the great Paris Exhibition, and of itself a novelty sufficient to attract visitors to the spot, and having, long before the Exhibition closed, completely defrayed the expense of its construction, with a handsome profit besides, its success has naturally provoked similar enterprises,—as, for instance, at Blackpool, a seaside resort in Lancashire, there has been erected an openwork metal tower, resembling the Paris structure, but of far less altitude. _Tall Buildings in American Cities._