. Bulletin. Science. Figure 4.—The proposed i,000-foot iron tower designed by Clarke, Reeves & Co. for the Cen- tennial Exhibition of 1876 at Philadelphia. (From Scientific American, Jan. 24, 1874, vol. 30, P- 47-) two widely separated points by the deep bands of trussing which formed the first and second platforms. A slight curvature inward was gi\en to the main piers to further widen the base and increase the stability of the structure. At a point slightly above the second platform, the four members converged to the extent that conventional bracing becaine more economical, and they were
. Bulletin. Science. Figure 4.—The proposed i,000-foot iron tower designed by Clarke, Reeves & Co. for the Cen- tennial Exhibition of 1876 at Philadelphia. (From Scientific American, Jan. 24, 1874, vol. 30, P- 47-) two widely separated points by the deep bands of trussing which formed the first and second platforms. A slight curvature inward was gi\en to the main piers to further widen the base and increase the stability of the structure. At a point slightly above the second platform, the four members converged to the extent that conventional bracing becaine more economical, and they were joined. That this theory was successful not only practically, but visually, is evident from the resulting work. The curve of the legs and the openings beneath the two lower platforms are primarily responsible for the Tower's graceful beauty as well as for its structural soundness. The design of the Tower was not actually the work of Eiffel himself but of two of his chief engineers, Emile Nouguier (1840-?) and Maurice Koechlin (1856-1946)—the men who had conducted the high pier studies—and the architect Stephen Sauvestre (1847-?). In the planning of the foundations, extreme care was used to ensure adequate footing, but in spite of the Tower's light weight in proportion to its bulk, and the low earth pressure it exerted, uneven pier settle- ment with resultant leaning of the Tower was con- sidered a dangerous possibility.^ To compensate for this eventuality, a device was used whose ingenious directness justifies a brief description. In the base of each of the 16 columns forming the four main legs was incorporated an opening into which an 800-ton hydraulic press could be placed, capable of raising the member slightly. A thin steel shim could then be inserted to make the necessary correction (fig. 5). The system was used only during construction to overcome minor erection discrepancies. In order to appreciate fully the problem which confronted the Tower's designers and sponso
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Keywords: ., bookauthorunitedstatesdepto, bookcentury1900, booksubjectscience
