Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress .. . Uponentering the chamber the upper door was shut, and air was pumped in untilthe pressure equaled the pressure in the cylinder underneath, which was alsothe pressure necessary to keep back the water from the excavation. Thelower door could then be opened and the working chamber entered. To pass P
Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress .. . Uponentering the chamber the upper door was shut, and air was pumped in untilthe pressure equaled the pressure in the cylinder underneath, which was alsothe pressure necessary to keep back the water from the excavation. Thelower door could then be opened and the working chamber entered. To pass PROGRESS IN CIVIL ENGINEERING 347 out, the reverse process in-inverse order was necessary. This was the firstpneumatic caisson ever sunk, although such plans had been proposed andeven patented in England several years before. The idea was essentially thepresent plan, but the process has been improved and enlarged. The requiredpressure is substantially that due to the weight of a column of water as highas the depth of the base of the caisson below the water surface. In the caseof the St. Louis bridge, the bottom of the caisson was sunk to 109 feet 8|inches below the water surface, which required an air pressure of about 47pounds per square inch in the working chamber. Such a pressure is danger-. FORMAL OPENING OP SUEZ of Ships in Canal. November 16, 1869. ous to those working in it. The men literally 4- live fast. Great exertion iseasily made, but is followed by corresponding exhaustion after leaving thecaisson. Those having heart disease, or who have been debilitated by previousexcesses, are liable to be seriously affected — generally by a form of paralysiswhich has been specifically named by physicians the caisson disease. Atthe St. Louis bridge, when working at .the greatest depths, the men Avere onlyworked four hours per day. in two-hour shifts. Facilities were likewise pro-vided to have them bathe, rest, and take hot coffee on coming out of the work-ing ch
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Keywords: ., bookcentury1800, bookdecade1890, bookidtri, booksubjectinventions
