Letter from the Secretary of WarU.S. Government Printing Office, 1881 |
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20 Gravel 3-inch pipe 50 per cent alluvial alluvium Apparently before drying April 26 Atchafalaya Atchafalaya rivers Average banks Blue clay bluff bolt in stone boring bottom Bullerton section Cairo caving cent Gravel channel color Contains particles copper bolt Corps of Engineers crests cross-section Dark sand Dark-gray sand deposit descent discharge distance E. H. WILSON eleva feet flood Fort Pillow Fulton section gauge gravel increases gray sand grows coarser high-water inch Island Landing levees Light-brown sand Location of Diameters Location of layers loess material mean velocity Memphis meters miles Mississippi River Commission ness nitric acid Notes and analysis Number observations occurred outlet parabola particles of lignite Plum Point pump quicksand Red River Respectfully submitted rise sample sandy clay scour sediment skiff slope stage stone post stratum stream surface above low-water SUTER thence Thick tion Tiptonville top of copper triangulation velocity vivi volume width
Popular passages
Page 2 - To direct and complete such surveys of said river, between the Head of the Passes near its mouth to its headwaters as may now be in progress, and to make such additional surveys, examinations, and investigations, topographical, hydrographical, and hydrometrical, of said river and its tributaries, as may be deemed necessary by said commission to carry out the objects of this act.
Page 4 - surveys of the Mississippi River between the Head of the Passes, near its month, and its headwaters, now in progress" ; to make " additional surveys and examinations of said river and its tributaries...
Page 7 - The bank revetments are intended not only to stop the constant, and in some localities very rapid, enlargement produced by erosion and caving of concave bends, but in addition thereto to check the growth of bars and shoals below by accretions supplied directly therefrom. The process of laying this revetment will vary greatly in different localities, but will commonly, or at least in many cases, consist in first freeing the bank of snags, stumps, and brush, and then placing a mattress, composed of...
Page 126 - I have but few words to say on the subject of levees. If the results I have given in this paper are correct, then the levee system, instead of favoring, as is alleged, the tendency of the bed of the river to rise, has precisely the reverse effect. By confining the waters within their limits, they increase the velocity and abrading power of the current, causing a deepening, rather than an elevation, of the bed.
Page 11 - ... it is believed that the repair and maintenance of the extensive lines already existing will hasten the work of channel improvement through the increased scour and depth of river-bed which they would produce during the high-river stages.
Page 11 - ... their closure be accompanied by the requisite contraction of the channel to a more nearly (uniform high-water width, a lowering of the flood-level may be expected to such extent as will ultimately render the maintenance of the levees as an aid to navigation practically needless above Red River, and greatly lessen the necessity of their permanent maintenance for that purpose below Red River, even at a reduced height. While it is not claimed that levees in themselves are necessary...
Page 11 - In a restricted sense, as auxiliary to a plan of channel improvement only, the construction and maintenance of a levee system is not demanded. But in a larger sense, as embracing not only beneficial eliects upon the channel, but as a protection against destructive floods, a levee system is essential ; and such system also, promotes and facilitates commerce, trade, and the postal service.
Page 11 - ... higher level within the river-bed than it would attain if not thus restrained. It would seem to follow, from the law that the, volume of water flowing in the bed determines the size, that prior to the construction of levees the area of the mean cross-section of bed of the Mississippi River...
Page 29 - When timber was convenient, stations were in some cases built and left standing. The observer stood on a platform disconnected from the instrument support. The stations were marked by stones 3 feet in length, dressed to 6 by 6 inches at one end, the balance rough. A small hole was drilled in the top. They were planted vertically, the top projecting but a few inches above ground. The targets were octagonal poles, of 3 inches diameter for the upper and 1 inch for the lower part of the work.