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. Bulletin - United States National Museum. Science. Figure 19.—The successive stages in the enlargement of a mid-19th-century railroad tunnel, using the Austrian system of timbering. MHT Figure 20. M. I. Brunel's Thames Tunnel, 1825-1843,1116 first driven beneath a body of water. MilT model—y4" scale. (Smithsonian photo 49260-F.) 220 II I I I I IN 240: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations
. Bulletin - United States National Museum. Science. Figure 19.—The successive stages in the enlargement of a mid-19th-century railroad tunnel, using the Austrian system of timbering. MHT Figure 20. M. I. Brunel's Thames Tunnel, 1825-1843,1116 first driven beneath a body of water. MilT model—y4" scale. (Smithsonian photo 49260-F.) 220 II I I I I IN 240: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States National Museum; Smithsonian Institution; United States. Dept. of the Interior. Washington : Smithsonian Institution Press, [etc. ]; for sale by the Supt. of Docs. , U. S. Govt Print. Off.
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Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience