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 .. . o that of pneumatic caissons — sinking a shaft through PROGRESS IN CIVIL ENGINEERING 341) excessively soft wet soil. The process is very recent, it having been inventedby Dr. F. H. Poetsch, of Prussia, in 1883. It has been used only in a veryfew cases up to the present time, but where it has been
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 .. . o that of pneumatic caissons — sinking a shaft through PROGRESS IN CIVIL ENGINEERING 341) excessively soft wet soil. The process is very recent, it having been inventedby Dr. F. H. Poetsch, of Prussia, in 1883. It has been used only in a veryfew cases up to the present time, but where it has been used it lias accom-plished results which were practically unattainable by ordinary methods. Avery brief description of one instance of its use will explain the general many years engineers had been battled in their attempts to sink a shallthrough 107 feet of quicksand at the Centrum mine, near Berlin, Poetsch sunk sixteen pipes in a circle around the proposed location of theshaft, and in thirty-three days had succeeded in producing a frozen circularwall six feet thick, within which the excavation was readily made and theshaft suitably lined. The freezing is accomplished by circulating a freezingliquid (chloride of calcium) through the tubes. After the shaft is completed. MANCHESTEB the pipes can be thawed loose from the wall of ice by simply circulating a hotliquid instead of a cold one. The pipes can then be redrawn uninjured, andused over again —a consideration of no small advantage. The process is notcheap. It would seldom, if ever, be used where the more common methodsare practicable: but for passing through very soft and wet soils it is fre-quently the only possible method. History records the construction of a ship canal across the Suez Isthmusas early as 600 b. c. ; that it continued in use for about 1400 years and wasthen abandoned. It was very small : all traces of it are now utterly authentic records of it are very meagre, and they s
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Keywords: ., bookcentury1800, bookdecade1890, bookidtri, booksubjectinventions
